Journal articles: 'Accelerated natural weathering'

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Kropat, Marcel, Martin A. Hubbe, and Frederik Laleicke. "Natural, accelerated, and simulated weathering of wood: A Review." BioResources 15, no. 4 (2020): 9998–10062. http://dx.doi.org/10.15376/biores.15.4.kropat.

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This review considers three aspects of the weathering of wood – natural weathering, accelerated weathering, and simulated weathering. Natural weathering begins when unprotected wood, such as an unpainted board, is exposed to cycles of solar radiation and rain. Unpainted barns and fenceposts take on a gray coloration and their surfaces may become rough, loosened, or checked with the passage of time. The underlying causes of such changes involve ultraviolet light, the effects of cyclic wetting and drying, and the action of certain fungi. Accelerated weathering tests have been used not only to evaluate the effectiveness of varnishes and paints, but also to aid in the understanding of factors affecting natural weathering. Simulated weathering usually has the goal of quickly and conveniently changing the appearance of fresh wood to give the impression of weathering. This might increase its appeal for various decorative purposes. Information about simulated weathering, though largely absent from the scientific literature, is very much alive in social media. This article considers the science behind all three types of weathering in the light of published accounts.

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Al Othman, Othman, Shan Faiz, and Muhammad Abduh Tuasikal. "Study of Natural and Accelerated Weathering on Mechanical Properties of Antioxidants Modified Low Density Polyethylene Films for Greenhouse." International Journal of Polymer Science 2014 (2014): 1–5. http://dx.doi.org/10.1155/2014/543930.

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Natural and accelerated weatherings were studied to inspect the effect of antioxidants to protect low-density polyethylene (LDPE) films for commercial application as greenhouse covering materials in Saudi Arabia. In this investigation, six different formulations of LDPE film with incorporation of antioxidants were prepared and compared with neat LDPE. The samples were extruded and blown into a film using twin-screw extruder and film blowing machine. The LDPE films were exposed for outdoor weathering in Riyadh during the period of 90 days (mid of June to mid of September) while the accelerated tests were performed by Weather-Ometer. The film having 0.2 wt% Alkanox-240 (AN-0.2) stabilizers showed the highest tensile strength among all samples during natural and 100-hour accelerated weathering (10.9 MPa and 21.8 MPa, resp.). The best elongation at break was witnessed in 0.2% Good-rite antioxidants which were 64% in natural weathering; however, 0.5% Good-rite antioxidants showed 232% in accelerated weathering. The film having 0.5 wt% Good-rite 3114 (GR-0.5) antioxidant could withstand 70 days during natural exposure before the tensile strength values were reduced to 2/3rd of the initial. The present study suggested that the addition of antioxidants Good-rite, Anox, and Alkanox can improve the mechanical strength, film’s life, effectiveness, and stability and they are suitable to be incorporated in LDPE for commercial greenhouse films.

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Yadav, Ranjana, Pandey K.K, and Vipin Kumar Chawla. "Bamboo lumber – an innovative sustainable raw material and an accelerated weathering study for establishing its durability." Journal of Bamboo and Rattan 21, no. 2 (2023): 77–85. http://dx.doi.org/10.55899/09734449.22/21.2c/332.

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Bamboo lumber was prepared using Bambusa bamboos species and its weathering performance was evaluated under natural and accelerated weathering. Specimens of bamboo lumber were exposed to natural weathering for 150 days. Another set of specimens were exposed to UV light source (UVA 360) in accelerated weathering tester up to 250 hours. A comparative study on the level of degradation in natural and accelerated weathering was made by evaluating CIEL*a*b* colour changes measured using a Hunter lab spectro-colorimeter. Rate of color change due to photo-degradation were evaluated. Results showed that all three color axes, viz. lightness (L*), redness (a*) and yellowness (b*) changed linearly with respect to time under natural exposure, but only L* was changed under accelerated weathering, keeping a* and b* values to be almost constant. Photodegradation of bamboo was mainly due to UV light absorption by chromophores present in the lignin, which constitutes about 32,2 % of total bamboo.

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Hyvärinen, Marko, Svetlana Butylina, and Timo Kärki. "Accelerated and Natural Weathering of Wood-Polypropylene Composites Containing Pigments." Advanced Materials Research 1077 (December 2014): 139–45. http://dx.doi.org/10.4028/www.scientific.net/amr.1077.139.

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In general, wood-polymer composites are vulnerable to weathering factors such as UV radiation, moisture, freeze-thaw action. Weathering can cause discoloration, chalking, dimensional change, and loss of mechanical properties of wood-polymer composites. This comparative study was focused on weatherability of wood–polypropylene composites made with and without pigments. Two types of inorganic pigments were applied: carbon black master-batch and synthetic iron oxide. Wood-polypropylene composite made without pigment was used as a reference. Also, composites prepared with addition of wollastonite were tested. The composite samples were exposed to outdoor weathering and in a parallel the accelerated UV weathering was conducted in xenon weathering chamber for the 2000 hours. The colour change was estimated by spectrophotometric method, and the change of Charpy impact strength after weathering was determined. The surface morphology was studied with scanning electron microscopy (SEM). The addition of pigments decreased the lightness of non-weathered composites. The change of lightness and total colour change of weathered composites were affected a lot by type of pigment and method of weathering. As, expected wood-polypropylene composite made with carbon black showed the best results in colour stability of composites exposed to weathering. SEM showed that accelerated weathering in the xenon chamber caused more significant changes in the morphology of the polymer surface layer of the composites than outdoor weathering. Charpy impact strength of all studied composites was found to retain after 2000 hours of outdoor weathering, although accelerated weathering caused significant reduction of Charpy impact strength of these composites.

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Lundin, Thomas, Steven M. Cramer, Robert H. Falk, and Colin Felton. "Accelerated Weathering of Natural Fiber-Filled Polyethylene Composites." Journal of Materials in Civil Engineering 16, no. 6 (2004): 547–55. http://dx.doi.org/10.1061/(asce)0899-1561(2004)16:6(547).

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Redhwi, Halim Hamid, Mohammad Nahid Siddiqui, Anthony L. Andrady, and Syed Hussain. "Accelerated Weatherability of the Low-Density Polyethylene Nanocomposites with Silica, Clay, and Zinc Oxide." Journal of Nanomaterials 2014 (2014): 1–5. http://dx.doi.org/10.1155/2014/516406.

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Nanocomposites based on low-density polyethylene (LDPE) with MMT clay, nanosilica, and nanoscale zinc oxide (at 5 wt.%) were prepared by melt processing and evaluated for durability using laboratory accelerated weathering. The changes in tensile properties of the nanocomposites with the duration of exposure were compared to data from natural weathering outdoors. The enhancement of degradation rates of the LDPE matrix by the presence of nanofillers in accelerated weathering is reported.

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Miranda de Lima, Adauto José, Setsuo Iwakiri, Kestur G. Satyanarayana, and María Guadalupe Lomelí-Ramírez. "Studies on the durability of wood-cement particleboards produced with residues of Pinus spp., silica fume, and rice husk ash." BioResources 15, no. 2 (2020): 3064–86. http://dx.doi.org/10.15376/biores.15.2.3064-3086.

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Wood-cement composites were considered as substitutes for wood or asbestos cement. This research is focused on the development, characterization, and durability of different wood-cement particle boards composed of wood waste [residual particles of pine species (Pinus spp.)], with silica fume or rice husk ash. The wood-cement panels produced by cold compression were evaluated for their physical and mechanical properties after accelerated and natural weathering for 28 and 91 days of curing, respectively. Results indicate that the performance of wood-cement panels containing the Pinus spp. residue was comparable to that of lignocellulosic aggregate in wood cement panels. Pine residue wood panels exhibited high levels of pozzolanic activity, suggesting that silica fume or rice husk ash could be used as a partial substitute in Portland cement. There was a significant loss of mechanical properties over time with both the reference panel and the panel produced with pozzolana. Although there was no direct correlation between the values of accelerated weathering tests and natural weathering tests, there was a larger degradation of the panels after 20 cycles of the accelerated weathering than that after 12 months of natural weathering. Morphology studies supported the observed results.

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Butylina, Svetlana, and Timo Kärki. "Resistance to weathering of wood-polypropylene and wood-wollastonite-polypropylene composites made with and without carbon black." Pigment & Resin Technology 43, no. 4 (2014): 185–93. http://dx.doi.org/10.1108/prt-03-2013-0019.

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Purpose – The purpose of this paper is to study natural and accelerated weathering of wood-polypropylene (WF-PP) and wood-wollastonite-polypropylene composites made with and without carbon black. Design/methodology/approach – Natural weathering was conducted in Ruokolahti, Finland in the time of year when solar radiation was maximal. The accelerated weathering tests included exposure to a xenon-arc source with and without spray, and a cyclic test consisting of water immersion–freeze–thaw stages. Findings – Both the type of weathering and the formulation of the composite determined the degree of change in their properties. Weathering, including xenon-arc exposure with spray resulted in much higher changes of colour of non-pigmented composites compared to natural weathering or xenon-arc weathering without spray. Both UV irradiation and moisture had an adverse effect on the Charpy impact strength of non-pigmented composites. Carbon black containing composites performed better than non-pigmented composites. Research limitations/implications – This study is a part of an ongoing research on the development of wood-polymer composites (WPCs) suitable for outdoor applications in Finnish climatic conditions. Outdoor weathering limited to 1,000 h cannot be used for the prediction of the service life of composites and was used here solely for comparative purposes. Originality/value – This paper will help to understand the effect of different weathering factors on the behaviour of WF-PP and wood-wollastonite-polypropylene composites made with and without carbon black (as UV stabiliser). The study demonstrated that while accelerated weathering tests provided useful information on the resistance of WF-PP composites to different weathering factors, they cannot be used alone to predict the behaviour of WPCs meant for outdoor application.

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Sandak, Anna, Jakub Sandak, Marion Noël, and Athanasios Dimitriou. "A Method for Accelerated Natural Weathering of Wood Subsurface and Its Multilevel Characterization." Coatings 11, no. 2 (2021): 126. http://dx.doi.org/10.3390/coatings11020126.

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The function of altering weathering factors and degradation mechanisms are essential for understanding the weathering process of materials. The goal of this work was to develop a method for the acceleration of natural weathering and to investigate the molecular, microstructure and macrostructure degradation of wood caused by the process. Tests were performed in the whole month of July, which, according to previous research, is considered as the most severe for weathering of wood micro-sections. Sample appearance was evaluated by colour measurement. Scanning electron microscopy was used for evaluation of the structural integrity and changes in the microstructure of wood morphological components. Changes on the molecular level were assessed by means of FT-IR spectroscopy. Observation of the effects of weathering allowed a better understanding of the degradation process. Typical structural damage, such as cracks on bordered pits and cross-field pits, and, as a consequence, their erosion, revealed the sequence of the degradation process. It was confirmed that earlywood was more susceptible to damage than latewood. Even if the weathering test was conducted for a relatively short time (28 days) the ultra-thin wood samples changed noticeably. The progress of alteration was similar as usually noticed for wood surfaces, but occurred at shorter exposure times. The estimated acceleration factor was ×3, compare to the natural weathering kinetics of wood. The research methodology presented can be used for the determination of the weather dose-response models essential to estimate the future service life performance of timber elements.

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Merah, Necar, Aziz Bazoune, and Zafar Khan. "Artificial and Natural Weathering of Chlorinated Polyvinyl Chloride (CPVC)." Advanced Materials Research 652-654 (January 2013): 1277–82. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.1277.

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The effects of natural and artificial weathering on mechanical properties of Chlorinated Polyvinyl Chloride (CPVC) pipe material are investigated. Tensile specimens, prepared from locally manufactured CPVC commercial pipes (4-in Schedule 80) were exposed for periods ranging from 2 weeks to 18 months in the harsh weather conditions of Dhahran, Saudi Arabia. The accelerated artificial weathering was carried out in the Q- Sun Xe-3-HS Xenon Test Chambers for periods ranging from 100 to 3000 hours. Standard tensile tests were performed before and after exposure. The tensile test results show that natural and accelerated artificial weathering had limited effects on the tensile and fracture strengths and modulus of elasticity of the material. However, the deterioration of the fracture strain is noticeable for exposure periods as short as 15 days of natural exposure and 100 hours of artificial UV exposure. Visual analysis of exposed specimens revealed that both types of exposures resulted in the discoloration of the specimens.

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Siddiqui, Mohammad N., Halim H. Redhwi, Anthony L. Andrady, Sarfaraz A. Furquan, and Syed Hussain. "Effect of Extensive Solar Ultra-Violet Irradiation on the Durability of High-Density Polyethylene- and Polypropylene-Based Wood–Plastic Composites." Polymers 17, no. 1 (2024): 74. https://doi.org/10.3390/polym17010074.

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The natural and laboratory-accelerated weathering of wood–plastic composites (WPCs) based on high-density polyethylene (HDPE) and polypropylene (PP) plastics was investigated in this study. Injection molded samples of WPCs with different loadings of wood fiber ranging from 0 to 36 wt.% of wood were subjected to laboratory-accelerated weathering and natural weathering. The integrity of samples weathered to different extents was tested using a standard tensile test and surface hardness test to investigate the dependence of these properties on the duration of weathering exposure. Tensile data were used to identify the loading of wood fibers in either plastic matrix that afforded superior ultra-violet (UV) stability. Tensile measurements under uniaxial strain yielded average values of tensile strength (TS), low-extension modulus (E), and elongation at break (EB). Both natural weathering outdoors and accelerated weathering in the laboratory showed that the TS and EB decreased while the E increased with the duration of exposure for all samples tested. The change in the average TS of composites with the duration of exposure offers valuable insights. The correlation between the tensile and hardness data for the WPC samples was explored. After naturally weathering at two exposure sites, the hardness of the WPCs was found to decrease between 8% to 12.5%, depending on the composition and exposure location parameters. Furthermore, no marked difference in performance with increasing wood fiber beyond 18 wt.% was observed. WPCs can be a key parameter in environmental sustainability by being used in the building and packaging industries, which reduces carbon emissions and waste generation.

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Sang, Tian, Christopher J. Wallis, Gavin Hill, and George J. P. Britovsek. "Polyethylene terephthalate degradation under natural and accelerated weathering conditions." European Polymer Journal 136 (August 2020): 109873. http://dx.doi.org/10.1016/j.eurpolymj.2020.109873.

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ISHIKAWA, Atsuko, Yutaka KATAOKA, Sumire KAWAMOTO, Masahiro MATSUNAGA, Masahiko KOBAYASHI, and Makoto KIGUCHI. "Correlation between natural and accelerated weathering of coated wood." MOKUZAI HOZON (Wood Protection) 40, no. 2 (2014): 55–63. http://dx.doi.org/10.5990/jwpa.40.55.

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Tidjani, Adams. "Photooxidation of polypropylene under natural and accelerated weathering conditions." Journal of Applied Polymer Science 64, no. 13 (1997): 2497–503. http://dx.doi.org/10.1002/(sici)1097-4628(19970627)64:13<2497::aid-app3>3.0.co;2-8.

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Chai, Ye Eun, Salma Chalouati, Hugo Fantucci, and Rafael M. Santos. "Accelerated Weathering and Carbonation (Mild to Intensified) of Natural Canadian Silicates (Kimberlite and Wollastonite) for CO2 Sequestration." Crystals 11, no. 12 (2021): 1584. http://dx.doi.org/10.3390/cryst11121584.

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Canada’s mineral reserves can play a very important role in curbing climate change if natural alkaline minerals are used for the process of mineral carbonation. In this work, the potential of using two Canadian natural silicates for accelerated carbonation is experimentally assessed: kimberlite mine tailing (Mg0.846Al0.165Fe0.147Ca0.067SiO3.381) from the Northwest Territories, and mined wollastonite ore (Ca0.609Mg0.132Al0.091Fe0.024SiO2.914) from Ontario. The aim of this work was to evaluate the weathering reactivity and CO2 uptake capacity via carbonation of these two comminuted rocks, both of which are made up of a mixture of alkaline minerals, under process conditions that spanned from milder to intensified. Research questions addressed include: does kimberlite contain a sufficient amount of reactive minerals to act as an effective carbon sink; is dehydroxylation necessary to activate kimberlite, and to what extent does it do this; do secondary phases of wollastonite hinder its reactivity; and can either of these minerals be carbonated without pH buffering, or only weathered? Incubator, slurry, and pressurized slurry methods of accelerated weathering and carbonation were used, and the effect of the process parameters (temperature, solid-to-liquid ration, reaction time, CO2 level, pH buffer) on the CO2 uptake and crystalline carbonates formation is tested. The reacted samples were analyzed by pH test, loss-on-ignition test, calcimeter test, and X-ray diffraction analysis. Results showed that wollastonite ore (rich in fast-weathering CaSiO3) is more suitable for accelerated carbonation than kimberlite tailing (containing slow-weathering hydrated magnesium silicates and aluminosilicates) when only its capability to rapidly form solid carbonates is considered. Incubator and pressurized buffered slurry methods proved to be most effective as under these conditions the precipitation of carbonates was more favorable, while the unbuffered slurry reaction conditions were more akin to accelerated weathering rather than accelerated carbonation.

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Ming, Jin Fa, Yao Xing Jiang, and Bao Qi Zuo. "Natural and Artificial Weathering of B.mori Silk Fabric." Advanced Materials Research 332-334 (September 2011): 3–10. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.3.

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Ultraviolet aging of B.mori silk fabric was studied under natural and artificial weathering conditions. Exposed samples were removed periodically and characterized by several analytical techniques. During both types of weathering, the results showed that yellowness index presented a rising trend with the extension of aging time; breaking strength of B.mori silk fabric decreased approximately 93.62%, 43.30% under natural aging 150 days and artificial accelerated aging 80 h, respectively; the peak intensity of amide I, and amide II, etc. significantly declined, even disappeared. At the same time, the conformation transition of B.mori silk was from random coil to β–pleated sheet following the prolonging of ultraviolet aging time. What’s more, the content of amino acid obviously declined especially histidine, tyrosine, and lysine etc. In addition, the results evidenced that during natural and artificial weathering, various performances of B.mori silk fabric changed similarly. So artificial weathering can be used to substitute for natural weathering for its weathering evaluation, which is helpful to understand the aging behavior and take measures to avoid aging and elongate its service life.

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Zhou, Qihua, Xuan Liu, Yanzhen Lu, Xiaoyao Dao, and Liuqing Qiu. "Accelerated Laboratory Weathering of Polypropylene/Poly (Lactic Acid) Blends." Polymers 15, no. 1 (2022): 17. http://dx.doi.org/10.3390/polym15010017.

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To solve the pollution problems that result from polypropylene (PP), suitable biopolymers such as poly (lactic acid) (PLA) were selected to blend with PP. Since PP/PLA blends are often exposed to the natural environment, it is necessary to study the photodegradation behavior of PP/PLA blends. In this paper, PP/PLA blends with different compositions were prepared by extrusion and subjected to the accelerated laboratory weathering equipment. The effects of compatibilizers on the degradation behavior of PP/PLA blends were also studied. The weatherability of PP/PLA blends was studied through weight loss, optical microscope, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results revealed that PP is easy to degrade than PLA during accelerated laboratory weathering. PP/PLA blends are susceptible to the accelerated laboratory weathering process, and PP-rich and PLA-rich blends reduce the weathering resistance. Moreover, the results indicate that the initial degradation temperature, melting temperature, and crystallization temperature decrease after weathering related to the decreased thermal stability of PP/PLA blends. For instance, the initial degradation temperature of PP/PLA8.2 reduces from 332.2 °C to 320.2 °C. Moreover, the compatibilized sample is generally more resistant to weathering conditions than the uncompatibilized one due to the higher compatibility of PP and PLA.

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Guo, Yan Fen, You Ji Tao, Gan Xin Jie, et al. "Degradation Behavior of Pure Polystyrene Subjected to Two Natural Climate Types and the Simulated Effect of Artificial Accelerated Weathering." Applied Mechanics and Materials 713-715 (January 2015): 2632–39. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.2632.

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Pure polystyrene (PS) was subjected to natural weathering in Qionghai (QH) and Ruoqiang (RQ) of China, representing hot and humid climate and xerothermic climate respectively. The degradation profile of pure PS was studied by Fourier Transform Infrared (FTIR) Spectroscopy, Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM), X-ray Photoelectron Spectroscopy (XPS) and Spectrophotometer. Artificial accelerated weathering tests protocol A and B were carried out to simulate hot and humid climate and xerothermic climate respectively. Results show that pure PS degrade slowly at the initial stage and then become faster. Color shift could be an appropriate indicator for evaluating simulated effect of artificial accelerated weathering and protocol A simulate hot and humid climate perfectly while protocol B turns out weak for xerothermic climate.

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Žiganova, Madara, Remo Merijs-Meri, Jānis Zicāns, Agnese Ābele, Ivan Bochkov, and Tatjana Ivanova. "Accelerated Weathering Testing (AWT) and Bacterial Biodegradation Effects on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/Rapeseed Microfiber Biocomposites Properties." Polymers 16, no. 5 (2024): 622. http://dx.doi.org/10.3390/polym16050622.

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In the context of sustainable materials, this study explores the effects of accelerated weathering testing and bacterial biodegradation on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/rapeseed microfiber biocomposites. Accelerated weathering, simulating outdoor environmental conditions, and bacterial biodegradation, representing natural degradation processes in soil, were employed to investigate the changes in the mechanical, thermal and morphological properties of these materials during its post-production life cycle. Attention was paid to the assessment of the change of structural, mechanical and calorimetric properties of alkali and N-methylmorpholine N-oxide (NMMO)-treated rapeseed microfiber (RS)-reinforced plasticized PHBV composites before and after accelerated weathering. Results revealed that accelerated weathering led to an increase in stiffness, but a reduction in tensile strength and elongation at break, of the investigated PHBV biocomposites. Additionally, during accelerated weathering, the crystallinity of PHBV biocomposites increased, especially in the presence of RS, due to both the hydrolytic degradation of the polymer matrix and the nucleating effect of the filler. It has been observed that an increase in PHBV crystallinity, determined by DSC measurements, correlates with the intensity ratio I1225/1180 obtained from FTIR-ATR data. The treatment of RS microfibers increased the biodegradation capability of the developed PHBV composites, especially in the case of chemically untreated RS. All the developed PHBV composites demonstrated faster biodegradation in comparison to neat PHBV matrix.

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Kajaks, Janis, Karlis Kalnins, and Juris Matvejs. "Accelerated Aging of WPCs Based on Polypropylene and Plywood Production Residues." Open Engineering 9, no. 1 (2019): 115–28. http://dx.doi.org/10.1515/eng-2019-0014.

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AbstractA lot of researchers are closely connected with natural, lignocellulose fibre containing bio-composites producing and studies. Various of polymer matrices, mainly polyolefins, combinations with natural fibres as a reinforcement are used. Our studies are focused on polypropylene based bio-composites containing birch plywood production by-product sanding dust (PSD) accelerated weathering processes. The nine groups of the samples with different composition were exposed in an accelerated weathering chamber for a total duration of the 1032 h. The surface colour, gloss, whiteness degree, micro-hardness and the tensile properties of the samples during the weathering were tested. In addition, the weathered surfaces were characterized by scanning electron microscopy (SEM) studies and by differential scanning calorimetry (DSC) investigations. The obtained results showed the following sight: after the weathering the surface of all samples is faded, also the changes of the gloss and of the whiteness degree occurs, but microhardness of the surface of specimens has decreased. The tensile strength of the samples changes a little, in the same time the tensile modulus increases significantly due to the decrease of the deformation ability of the polypropylene matrix and recrystallization processes in PP. The SEM images taken at the 100 and 500 times of the magnification revealed a lot of the different shape and sizes cracks on the surface of the weathered samples. DSC measurements showed the increase of the degree of crystallinity of the polypropylene after the weathering due to the recrystallization process in the polypropylene matrix.

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Baukh, Viktor, Hendrik P. Huinink, Olaf C. G. Adan, and Leendert G. J. van der Ven. "Natural versus accelerated weathering: Understanding water kinetics in bilayer coatings." Progress in Organic Coatings 76, no. 9 (2013): 1197–202. http://dx.doi.org/10.1016/j.porgcoat.2013.03.029.

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Gugumus, F. "The performance of light stabilizers in accelerated and natural weathering." Polymer Degradation and Stability 50, no. 1 (1995): 101–16. http://dx.doi.org/10.1016/0141-3910(95)00134-8.

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Al-Sulaiman, F., Z. Khan, N. Merah, M. A. Kounain, and M. Mehdi. "Effects of weathering on failure pressure of filament-wound GFRP thermoset pipes." Journal of Composite Materials 45, no. 6 (2010): 645–55. http://dx.doi.org/10.1177/0021998310377933.

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Burst tests have been performed on the glass fiber-reinforced (GFR) thermoset pipes before and after exposure to natural and accelerated environmental conditions. The main objective of this study was to explore the effects of long-term natural outdoor and artificial accelerated environmental conditions on the burst resistance of the vinyl-based and epoxy-based GFR filament wound thermoset pipes which are targeted for use in crude oil transportation. The pipes were exposed to natural outdoor and accelerated dry heat conditions. The results show that these environments did not produce any noticeable degradation in the hydrostatic burst resistance of the pipes up to 24 months of natural exposure and up to 10,000 h of dry heat exposure.

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Keržič, Eli, Boštjan Lesar, and Miha Humar. "Influence of weathering on surface roughness of thermally modified wood." BioResources 16, no. 3 (2021): 4675–92. http://dx.doi.org/10.15376/biores.16.3.4675-4692.

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Wood is one of the most important building materials. Thermally modified wood is entering the market and replacing wood preservatives and tropical wood species in some applications. Thermally modified wood is exposed to weathering similarly as other wood-based building materials. It has been reported that if thermally modified wood is exposed to weathering, its moisture performance might decrease fairly fast. Moisture performance reflects the material’s ability to remain dry and dry out fast when wet. The aim of this study was to determine whether this phenomenon is associated with crack formation or roughness. Norway spruce, thermally modified spruce, wax-treated thermally modified spruce, and European larch heartwood samples were exposed to artificial accelerated weathering and natural weathering for 9, 18, and 27 months. Samples were subsequently isolated, and their roughness was determined with a confocal laser scanning microscope on axial and longitudinal surfaces at 10× and 50× magnification. After weathering, roughness increased on both axial and longitudinal surfaces. This was evident from the profile 2D measurements (Ra) and surface 3D measurements (Sa). The effect of natural weathering on roughness was higher than artificial accelerated weathering, presumably due to synergistic effects of abiotic and biotic factors. This may be associated with Wenzel’s theory on the influence of roughness on the contact angles of water on the surface; namely, increased roughness will decrease the contact angle on hydrophilic surfaces.

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Alao, Percy, Kevin Visnapuu, Heikko Kallakas, Triinu Poltimäe, and Jaan Kers. "Natural Weathering of Bio-Based Façade Materials." Forests 11, no. 6 (2020): 642. http://dx.doi.org/10.3390/f11060642.

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Although there is a global awareness that the exploitation of non-renewable materials is unsustainable, there has been limited interest in fully utilizing natural, renewable resources like wood and its products because of the service durability concerns. One such issue is the aesthetical degradation of wooden facades due to the impact of weathering. This research was carried out as an international cooperation project to ascertain the weathering resistance of bio-based façade materials under the Estonian climate. In total, 120 bio-based façade materials obtained from 31 different companies, universities and research institutions from 17 countries were investigated. The specimens were placed on an exposure rack, inclined at an angle of 45° located at 59°23′50.6″ N 24°39′24.0″ E and then subjected to accelerated natural weathering for 2 years. Parameters such as precipitation, UV index, temperature and relative humidity were measured during the period of the natural weathering. The influence of the weathering on the colour change and cracks on the surface of test specimens was evaluated using Minolta Chroma Meter CR-121 (Konica Minolta INC., Tokyo, Japan) and Avongard Check Width Gauge (Avongard Ltd., Gloucestershire, UK), respectively. The results showed that the untreated natural wood façade materials presented the least resistance to weathering, while 63 of the tested materials developed checks. The outcome of this study is essential to the optimization of software-simulating changes in the appearance of façade materials in outdoor conditions.

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Kasagepongsan, Chainuson, and Sunisa Suchat. "Novel Engineered Materials: Epoxy Resin Nanocomposite Reinforced with Modified Epoxidized Natural Rubber and Fibers for Low Speed Wind Turbine Blades." Polymers 13, no. 16 (2021): 2761. http://dx.doi.org/10.3390/polym13162761.

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The objective of this study was to investigate nanocomposite materials with good outdoor resistance for wind turbine blade application. The nanocomposites based on epoxy resin with 5% of epoxidized natural rubber (ENR 50), 3% of nanofiller, and glass fibers, were subjected to experiments. The weathering resistance of nanocomposites was evaluated from the change in mechanical properties caused by accelerated aging, induced by UVB radiation in a weathering chamber. The accelerated aging improved tensile strength by about 35% at 168 h of exposure to UVB, via a curing effect. The nanocomposites were optimized for all the parts of wind turbine blades (Savonius and Darrieus types) that are generally designed for high strength, low weight, weathering resistance, and low rotational speed (2 m/s). A tree wind turbine with nanocomposite blades produced 5 kW power output when tested. Based on the findings in this work, the innovative nanocomposites have potential in manufacturing wind turbines to generate electricity.

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Carmona-Quiroga, Paula M., Robert M. J. Jacobs, Sagrario Martínez-Ramírez, and Heather A. Viles. "Durability of anti-graffiti coatings on stone: natural vs accelerated weathering." PLOS ONE 12, no. 2 (2017): e0172347. http://dx.doi.org/10.1371/journal.pone.0172347.

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Puterman, Moshe. "Natural and accelerated weathering of PVC and polypropylene waste-water pipes." Materials and Structures 22, no. 3 (1989): 170–75. http://dx.doi.org/10.1007/bf02472184.

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Brown, H. M., I. D. MacGregor, and L. A. Maclsaac. "Comparison of accelerated and natural weathering of coil-coated galvanised steel." Construction and Building Materials 5, no. 3 (1991): 123–26. http://dx.doi.org/10.1016/0950-0618(91)90062-p.

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Chopra, Swamini, Kavita Pande, Priadarshni Puranam, et al. "Explication of mechanism governing atmospheric degradation of 3D-printed poly(lactic acid) (PLA) with different in-fill pattern and varying in-fill density." RSC Advances 13, no. 11 (2023): 7135–52. http://dx.doi.org/10.1039/d2ra07061h.

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With accelerated weathering test instruments lacking the ability to correlate with actual instabilities during application, this work makes an attempt to explore the degradation of PLA under natural atmospheric conditions of UV, rain and humidity.

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Chen, Cheng Chung, Chao Shi Chen, Jyun Yong Jhan, and Ming Sheng Ko. "The Improve of Accelerated Carbonation on Engineering Properties of Basic Oxygen Furnace Slag." Key Engineering Materials 709 (September 2016): 42–45. http://dx.doi.org/10.4028/www.scientific.net/kem.709.42.

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Basic oxygen furnace (BOF) slag is characterized by high hardness, low abrasion, and high roughness. It is suitable as graded aggregate for engineering applications. However, the conversion process generated a great amount of unreacted free CaO, resulting in expansion and thus making the slag inconvenient for use in engineering applications. Accelerated carbonation of BOF slag is equivalent to natural weathering. Moreover, it can effectively shorten the weathering time. This study found that accelerated carbonation not only reduce expansion behaviors but also strengthen physical and mechanical properties. According to test results, the abrasion resistant, soundness, California bearing ratio, shear strength, and compressive strength have increased after carbonation.

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Yang, Teng Chun. "Improvement of Accelerated Weathering Test through Physicochemical Analysis for Polymeric Materials in Building Construction." Applied Mechanics and Materials 479-480 (December 2013): 1119–23. http://dx.doi.org/10.4028/www.scientific.net/amm.479-480.1119.

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In civil engineering, the long-term service life of buildings as environmental measures is one of important performances being comparable to structure and fire safety, and it is demanded to improve durability of materials in building construction. This improvement of material durability is highly associating with lifetime of building, and so as not to reach the limit state of building components. It is imperative to determine a specific means and method in order to identify the surrounding environment on the deteriorating effect for building components and materials, as well as predicting a process of degradation phenomena and the limit state of buildings. As part of building materials, polymeric materials become widespread in civil engineering because of taking advantage of excellent property, such as lightweight, high corrosion resistance, and good formability. However, we should look ahead the lifecycle cost in order to have effective application of this material, so it is necessary to understand the lifecycle of such material. In weathering, outdoor weathering test is the surest way to clarify exactly how a material, component, or products degrade by environmental stresses in an acceptable timeframe, but it usually takes few years to decades to obtain a useful or referable result. Meanwhile, accelerated weathering test methods have been proposed as a method to obtain the results in a short period of time than outdoor weathering test. However, the method of estimating a material durability in the actual environment from these obtained data has not yet been established.In this section, it would be showing some attentions for comparison of the results from outdoor and accelerated weathering test. Then the need for investigating weatherability of polymeric materials through physicochemical analysis are emphasized to improve the relevance and precision of durability under field and laboratory weathering test. Lastly, introducing the design of accelerated weathering method based on natural weathering characteristics.

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Zhang, Hongshen, and Hongfei Zheng. "Artificial and Natural Aging of Polypropylene Used in Passenger Vehicle Bumpers." Materiale Plastice 58, no. 2 (2021): 201–10. http://dx.doi.org/10.37358/mp.21.2.5492.

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Polypropylene (PP) has a wide range of applications in the automobile bumpers due to its many excellent properties. Mechanical properties of PP for automobile bumpers are investigated through an artificial accelerated aging test. The aging rules after different years of normal use and the artificial accelerated aging test are analyzed. The correlation between natural and artificially accelerated aging is also explored. It provides a reference for the study of the aging properties of polymers for automotive applications. Results show that the UV aging test can effectively simulate changes in tensile and bending strengths after natural aging and can be used to evaluate the weathering resistance of PP materials used in automotive bumpers. The tensile and bending strengths of these materials remain good during aging, and elongation is sensitive to aging. The short-term artificial accelerated aging test does not exert a significant influence on the impact strength of materials, and artificial accelerated aging does not completely reproduce the aging process of the material.

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Pospíšil, J., Z. Horák, J. Pilař, S. Nešpurek, N. C. Billingham, and W. D. Habicher. "Effect of Testing Conditions on Performance and Durability of Stabilisers in Plastics." Polymers and Polymer Composites 11, no. 2 (2003): 81–90. http://dx.doi.org/10.1177/096739110301100203.

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The accelerated thermal aging and weathering of stabilised plastics provides information on stabiliser efficiency and polymer durability more quickly than natural testing. This allows the monitoring of the material properties of plastics in the foreseen application environment and the development of new stabilisation formulations. The harshness of the testing method affects the individual processes involved regarding their activation energies and mechanisms, the physical relations in the polymer – stabiliser system, and the chemical and physical processes accounting for the consumption of stabilisers. The principal factors affecting any comparison of accelerated results with natural testing are outlined.

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Rashid, Muhammad Imran, Sikander Rafiq, Mahnoor Asif, and Ayesha Mobeen. "Weathering of Wood and Rocks and the Role of Coating in Protection." Non-Metallic Material Science 5, no. 2 (2024): 11–25. http://dx.doi.org/10.30564/nmms.v5i2.6090.

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This article explores the effect of weathering on the degradation of wood and rocks and discusses its prevention strategies and safety aspects. Weathering, including natural, enhanced, accelerated, silicates, polymer degradation and erosion is discussed in this article. Rocks weather naturally very slowly and gradually. Minerals weathering and silica-rich layer formation during single-stage and two-stage carbonation like serpentinization of rocks are discussed. A substantial amount of work has been performed for polymeric coatings globally to extend the life of coating surfaces. The ideal coating system would combine the advantages of performance offered by solvent-based coatings with the advantages offered by water-based coatings in the areas of environmental protection, health and safety. Weathering prevention will stop the wastage of materials.

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Fontaine, Gaëlle, Véronique Marchetti, and Serge Bourbigot. "Effects of accelerated and natural weathering on fire-retarded industrial wood composite." Journal of Fire Sciences 40, no. 5 (2022): 385–402. http://dx.doi.org/10.1177/07349041221102059.

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This study shows the impact of aging on the fire behavior of a fire-retarded polyvinyl chloride wood composite cladding intended for outdoor use. Two sets of composite wood cladding elements were examined: one aged naturally under exposed outdoors conditions for 1 year and the second, which underwent artificial accelerated aging. Optical microscopy, electron probe micro-analysis, and solid-state nuclear magnetic resonance of 27Al were used to investigate changes in the material properties after aging, distribution of chemical compounds, and aluminum environment. This study reveals the impact of different aging procedures on the physicochemical modifications of the composite material. In addition, after aging, the fire behavior of the two sets of composites as a function of fire exposure time was evaluated by cone calorimetry. Then, the natural aged composite was evaluated on a larger scale with the single burning item. The results surprisingly demonstrate that whatever the aging, the fire behavior of these wood composite was not affected.

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MATSUDA, Hisashi, Masashi YAGAMI, Yusuke TAJIMA, Nobuyoshi WATANABE, Hideaki SATO, and Masashi TAKEYAMA. "Accelerated weathering study on practical use plasma electrode using Natural wind tunnel." Proceedings of Conference of Hokkaido Branch 2020.57 (2020): 35–36. http://dx.doi.org/10.1299/jsmehokkaido.2020.57.35.

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Elert, K., and C. Cardell. "Weathering behavior of cinnabar-based tempera paints upon natural and accelerated aging." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 216 (June 2019): 236–48. http://dx.doi.org/10.1016/j.saa.2019.03.027.

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Deflorian, F., S. Rossi, L. Fedrizzi, and C. Zanella. "Comparison of organic coating accelerated tests and natural weathering considering meteorological data." Progress in Organic Coatings 59, no. 3 (2007): 244–50. http://dx.doi.org/10.1016/j.porgcoat.2006.09.036.

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TIDJANI, ADAMS, ANICET O. DASILVA, ELISABETH FANTON, and RENÉ ARNAUD. "NATURAL AND ACCELERATED WEATHERING OF STABILIZED COPOLYMER ETHYLENE-PROPYLENE (LOW ETHYLENE CONTENT)." Journal of Macromolecular Science, Part A 36, no. 4 (1999): 633–44. http://dx.doi.org/10.1081/ma-100101553.

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Russo, Pietro, Domenico Acierno, Luca Marinucci, Antonio Greco, and Mariaenrica Frigione. "Influence of natural and accelerated weathering on performances of photoselective greenhouse films." Journal of Applied Polymer Science 127, no. 3 (2012): 2213–19. http://dx.doi.org/10.1002/app.37914.

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Stadlmann, Alexander, Maximilian Pramreiter, Robert Stingl, Christian Kurzböck, Thomas Jost, and Ulrich Müller. "Durability of Wood Exposed to Alternating Climate Test and Natural Weathering." Forests 11, no. 9 (2020): 953. http://dx.doi.org/10.3390/f11090953.

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The use of wood-based materials in the automotive industry is currently under discussion and investigation. One of the major material requirements for such applications is sufficient weathering stability. This can be demonstrated by an accelerated aging process in which the samples are exposed to changing climatic conditions and a spray mist of an aqueous NaCl solution. The effects of media salt (NaCl) on the mechanical and physical properties of wood have scarcely been investigated. The presented study investigated the changes in bending strength (MOR), modulus of elasticity (MOE), and impact bending strength (α) of naturally and artificially weathered oak (Quercus spp.) and birch (Betula pendula Roth) wood. The tests provided comparable results. The decrease under natural weathering of oak was 3.73%, 4.69%, and 6.45% for MOR, MOE, and α. Under artificial weathering the decrease observed for oak was 7.33%, 10.87%, and 16.29% and 3.2%, 8.21%, and 4.03% for birch respectively. It is remarkable that α increased for birch wood at the beginning of the artificial weathering cycles. The penetration of the aqueous NaCl solution into the wood substance resulted in an increase in the wood’s equilibrium moisture content (EMC), which can be explained by the stronger hygroscopic properties of NaCl compared to wood. The higher impact strength at the beginning of artificial weathering can be partly explained by this increase in EMC. In order to investigate the penetration behavior of salt into the wood substrate, the artificially weathered samples were examined by means of energy dispersive X-ray analysis (EDX) and it was shown that the salt concentration changes significantly over the weathering cycles and sample cross-section.

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Aytin, Ayhan, and Nevzat Çakıcıer. "Weathering’s effect on color and roughness in some heat-treated wood species with modified water-based varnish." BioResources 17, no. 4 (2022): 6358–76. http://dx.doi.org/10.15376/biores.17.4.6358-6376.

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Heat treatment in wood materials and the use of water-based varnishes (WBV) in furniture made from heat-treated wood materials come to the fore in terms of supporting environmentally friendly production in the wood sector. In this study, the total color changes (ΔΕ*) and surface roughness (SR) were investigated after heat-treated tree species were exposed to natural and accelerated weathering with and without varnish. In this context, test samples were first divided into two groups. Surface treatment was applied to the samples in the first group by applying modified WBV (A1) and normal WBV (A2), and the second group was left unvarnished. Then, one group of the varnished samples was subjected to natural weathering (NAT) for 90 days and the other group was subjected to accelerated weathering (QUV) for 720 h with VAS samples, and then the ΔΕ* and SR values of the samples were calculated. The results revealed that ΔΕ* was the lowest in the QUV WBV group, and NAT was more effective than QUV in ΔΕ*. The highest SR values among all groups were measured in the VAS group, and among the varnished samples, there was no statistical difference between A1 and A2 in SR values, except for Rq.

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Hashim, Ummu Raihanah, Aidah Jumahat, Mohammad Jawaid, Rudi Dungani, and Salman Alamery. "Effects of Accelerated Weathering on Degradation Behavior of Basalt Fiber Reinforced Polymer Nanocomposites." Polymers 12, no. 11 (2020): 2621. http://dx.doi.org/10.3390/polym12112621.

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This work aims to give insight on the effect of accelerated weathering, i.e., the combination of ultraviolet (UV) exposure and water spraying, on the visual and mechanical properties of basalt fiber reinforced polymer (BFRP) composites. The solvent exchange method, sonication and high shear milling technique were used to prepare the nanocomposite laminates. Three types of laminates were fabricated, i.e., unmodified BFRP, nanosilica modified BFRP and graphene nanoplatelet (GNP) modified BFRP composites with the total fiber loading of 45 wt.%. Glass fiber reinforced polymer (GFRP) laminate was also prepared for performance comparison purposes between the natural and synthetic fibers. The laminates were exposed to UV with a total weathering condition of 504 h using a Quantum-UV accelerated weathering tester. The weathering condition cycle was set at 8 h 60 °C UV exposure and 4 h 50 °C condensation. The discoloration visual inspection on the tested specimen was observed under the optical microscope. The obtained results showed that the UV exposure and water absorption caused severe discoloration of the laminates due to photo-oxidation reaction. The effect of weathering conditions on tensile and flexural properties of unmodified BFRP composites indicated that the UV exposure and water absorption caused reduction by 12% in tensile strength and by 7% in flexural strength. It is also found that the reduction in tensile and flexural properties of nanomodified BFRP composites was smaller than the unmodified system. It concluded from this work, that the mineral based composites (i.e., BFRP) has high potential for structural applications owing to its better properties than synthetic based composites (i.e., GFRP).

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Park, Ju-Hyun, Myoung-Nam Kim, Se-Rin Park, and Sun-Myung Lee. "Properties and Lightfastness of Natural and Artificial Azurite Used As Painting Pigment." Korean Journal of Metals and Materials 61, no. 9 (2023): 704–13. http://dx.doi.org/10.3365/kjmm.2023.61.9.704.

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Azurite is an inorganic pigment commonly used in traditional painting arts and even today. This pigment has two types: natural azurite and synthetic artificial azurite, called blue verditer or blue bice. Because they have the same structure and similar appearance they are difficult to distinguish. The purpose of this study is to compare these two types pigments, focusing on material properties and accelerated weathering behavior. Natural azurite consist of copper carbonate and mineral compounds like quartz, kaolinite. On the other hand, artificial azurites are synthesized using azurite and calcite. As a result of thermal analysis, unlike natural azurite, the calcite in artificial azurite resulted in weight loss at three temperatures, at approximately 350 ℃, 650 ℃, and 840 ℃. According to the microscope analysis results, natural azurites have clearly blue angular particles with sharp edges, produced by crushing. Artificial azurite showed spherules and aggregates with tiny rounded or fibrous particles. After accelerated weathering tests, the natural azurites had no change in color, particle shape or original components, but the artificial azurites noticeably changed color and shape. The color changes of artificial azurites occurred due to the growth of calcite crystallite, a slight new product formation, and change in particle shape. Even though natural azurites are more expensive pigments, they provide superior color durability and particle shape stability compared to artificial azurites.

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MOCEIKIS, Rimvydas, Asta KIČAITĖ, Gintautas SKRIPKIŪNAS, and Aleksandrs KORJAKINS. "AGEING MODELS AND ACCELERATED AGEING TESTS OF GLASS FIBER REINFORCED CONCRETE." Engineering Structures and Technologies 10, no. 1 (2018): 10–17. http://dx.doi.org/10.3846/est.2018.1467.

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Glass fiber reinforced concrete (GRC) is used for 40 years to create world’s most stunning and complex architectural elements due to its high mechanical properties, particularly flexural strength. Yet it is very important to note that any type of glass fibers in the concrete matrix are undergoing complex ageing processes, resulting to significant decrease of initial mechanical characteristics of this composite material under natural weathering conditions. Aspects of GRC durability are mainly dependent from the properties of fibers and interaction between them and concrete matrix. In this article, long term strength retention of this composite material is discussed, existing experimental data of weathering tests presented, and main corrosion mechanisms explained. Lack of knowledge about freeze- thaw resistance of glass fiber reinforced concrete is addressed. Finally, latest attempts of GRC durability improvement are reviewed, such as adding micro fillers, polymers to the concrete matrix and enhancing surface of fibers in Nano scale.

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White, C. C., K. T. Tan, D. L. Hunston, et al. "Laboratory accelerated and natural weathering of styrene–ethylene–butylene–styrene (SEBS) block copolymer." Polymer Degradation and Stability 96, no. 6 (2011): 1104–10. http://dx.doi.org/10.1016/j.polymdegradstab.2011.03.003.

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Akers, S. A. S., and J. B. Studinka. "Ageing behaviour of cellulose fibre cement composites in natural weathering and accelerated tests." International Journal of Cement Composites and Lightweight Concrete 11, no. 2 (1989): 93–97. http://dx.doi.org/10.1016/0262-5075(89)90119-x.

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Nobari Azar, Farzad A., and Murat Şen. "Effects of accelerator type on stress relaxation behavior and network structure of aged natural rubber/chloroprene rubber vulcanizates." Journal of Elastomers & Plastics 49, no. 5 (2016): 381–96. http://dx.doi.org/10.1177/0095244316663268.

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Natural rubber/chloroprene rubber (NR/CR) blends are among the commonly used rubber blends in industry and continuously are exposed to severe weather changes. To investigate the effects of accelerator type on the network structure and stress relaxation of unaged and aged NR/CE vulcanizates, tetramethyl thiuram disulfide, 2-mercaptobenzothiazole, and diphenyl guanidine accelerators have been chosen to represent fast, moderate, and slow accelerator groups, respectively. Three batches have been prepared with exactly the same components and mixing conditions differing only in accelerator type. Temperatures scanning stress relaxation and pulse nuclear magnetic resonance techniques have been used to reveal the structural changes of differently accelerated rubber blends before and after weathering. Nonoxidative thermal decomposition analyses have been carried out using a thermogravimetric analyzer. Results indicate that there is a strong interdependence between accelerator type and stress relaxation behavior, network structure, cross-linking density, and aging behavior of the blends. Accelerator type also affects decomposition energy of the blends.

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Magill, Courtney, and Frank Matero. "In Situ Performance Assessment and Evaluation of Hydrophobic and Ultraviolet Protective Treatments for Historic Log Structures." UW National Parks Service Research Station Annual Reports 38 (January 1, 2015): 100–111. http://dx.doi.org/10.13001/uwnpsrc.2015.4105.

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Beginning in the summer of 2015, research was conducted on protective wood coatings and accelerated weathering testing methods for architectural log and timber. A rack for supplementary natural weathering testing of hydrophobic and ultraviolet protective surface treatments for logs was also erected as a subsequent phase at Grand Teton National Park. This laboratory and field research is part of an ongoing project to develop an appropriate treatment for historic log structures in the region that will preserve their original fabric while maintaining the intended historic appearance of the buildings, i.e., unpainted. The weathering rack will be in place for upwards of five years to verify the lab-based results from Phase I and to determine the long-term durability of the chosen treatments on already aged materials in situ. This report addresses the methods and materials for preparation of the weathering rack and samples as well as the methods being used to monitor their progress and initial results. Readings will be taken yearly to monitor the effects of weathering on each treatment.

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Journal articles on the topic 'Accelerated natural weathering'

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