Log in

Relevant bibliographies by topics / Polyolefin / Journal articles

To see the other types of publications on this topic, follow the link: Polyolefin.

Journal articles on the topic 'Polyolefin'

Author: Grafiati

Published: 4 June 2021

Last updated: 22 June 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Polyolefin.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Kresge, E. N. "Polyolefin Thermoplastic Elastomer Blends." Rubber Chemistry and Technology 64, no. 3 (July 1, 1991): 469–80. http://dx.doi.org/10.5254/1.3538564.

Full text

Abstract:

Abstract Thermoplastic elastomers based on blends of polyolefins are an important family of engineering materials. Their importance arises from a combination of rubbery properties along with their thermoplastic nature in contrast to thermoset elastomers. The development of polyolefin thermoplastic elastomer blends follows somewhat that of thermoplastic elastomers based on block copolymers such as styrene-butadiene-styrene triblock copolymer and multisegmented polyurethane thermoplastic elastomers which were instrumental in showing the utility of thermoplastic processing methods. Polyoleflns are based on coordination catalysts that do not easily lend themselves to block or multisegmented copolymer synthesis. However, since polyolefins have many important attributes favorable to useful elastomeric systems, there was considerable incentive to produce thermoplastic elastomers based on simple α-olefins by some means. Low density, chemical stability, weather resistance, and ability to accept compounding ingredients without compromising physical properties are highly desirable. These considerations led to the development of polyolefin thermoplastic elastomer blends, and two types are now widely used: blends of ethylene-propylene rubber (EPM) with polypropylene (PP) and blends of EPDM and PP in which the rubber phase is highly crosslinked. This article reviews the nature of these blends. Both physical and Theological properties are very dependent on the morphology and crosslink density of the blend system. Moreover, the usefulness of practical systems depends extensively on compounding technology based on added plasticizers and fillers.

APA, Harvard, Vancouver, ISO, and other styles

2

Zhang, Ni, Mingzhu Ding, and Yingjin Yuan. "Current Advances in Biodegradation of Polyolefins." Microorganisms 10, no. 8 (July 29, 2022): 1537. http://dx.doi.org/10.3390/microorganisms10081537.

Full text

Abstract:

Polyolefins, including polyethylene (PE), polypropylene (PP) and polystyrene (PS), are widely used plastics in our daily life. The excessive use of plastics and improper handling methods cause considerable pollution in the environment, as well as waste of energy. The biodegradation of polyolefins seems to be an environmentally friendly and low-energy consumption method for plastics degradation. Many strains that could degrade polyolefins have been isolated from the environment. Some enzymes have also been identified with the function of polyolefin degradation. With the development of synthetic biology and metabolic engineering strategies, engineered strains could be used to degrade plastics. This review summarizes the current advances in polyolefin degradation, including isolated and engineered strains, enzymes and related pathways. Furthermore, a novel strategy for polyolefin degradation by artificial microbial consortia is proposed, which would be helpful for the efficient degradation of polyolefin.

APA, Harvard, Vancouver, ISO, and other styles

3

Goring, Paul D., Colin Morton, and Peter Scott. "End-functional polyolefins for block copolymer synthesis." Dalton Transactions 48, no. 11 (2019): 3521–30. http://dx.doi.org/10.1039/c9dt00087a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Fazekas, Timothy J., Jill W. Alty, Eliza K. Neidhart, Austin S. Miller, Frank A. Leibfarth, and Erik J. Alexanian. "Diversification of aliphatic C–H bonds in small molecules and polyolefins through radical chain transfer." Science 375, no. 6580 (February 4, 2022): 545–50. http://dx.doi.org/10.1126/science.abh4308.

Full text

Abstract:

The ability to selectively introduce diverse functionality onto hydrocarbons is of substantial value in the synthesis of both small molecules and polymers. Herein, we report an approach to aliphatic carbon–hydrogen bond diversification using radical chain transfer featuring an easily prepared O -alkenylhydroxamate reagent, which upon mild heating facilitates a range of challenging or previously undeveloped aliphatic carbon–hydrogen bond functionalizations of small molecules and polyolefins. This broad reaction platform enabled the functionalization of postconsumer polyolefins in infrastructure used to process plastic waste. Furthermore, the chemoselective placement of ionic functionality onto a branched polyolefin using carbon–hydrogen bond functionalization upcycled the material from a thermoplastic into a tough elastomer with the tensile properties of high-value polyolefin ionomers.

APA, Harvard, Vancouver, ISO, and other styles

5

Zhu, Lei, Haojie Yu, Li Wang, Yusheng Xing, and Bilal Ul Amin. "Advances in the Synthesis of Polyolefin Elastomers with “Chain-walking” Catalysts and Electron Spin Resonance Research of Related Catalytic Systems." Current Organic Chemistry 25, no. 8 (April 28, 2021): 935–49. http://dx.doi.org/10.2174/1385272825666210126100641.

Full text

Abstract:

In recent years, polyolefin elastomers play an increasingly important role in industry. The late transition metal complex catalysts, especially α-diimine Ni(II) and α-diimine Pd(II) complex catalysts, are popular “chain-walking” catalysts. They can prepare polyolefin with various structures, ranging from linear configuration to highly branched configuration. Combining the “chain-walking” characteristic with different polymerization strategies, polyolefins with good elasticity can be obtained. Among them, olefin copolymer is a common way to produce polyolefin elastomers. For instance, strictly defined diblock or triblock copolymers with excellent elastic properties were synthesized by adding ethylene and α-olefin in sequence. As well as the incorporation of polar monomers may lead to some unexpected improvement. Chain shuttling polymerization can generate multiblock copolymers in one pot due to the interaction of the catalysts with chain shuttling agent. Furthermore, when regarding ethylene as the sole feedstock, owing to the “oscillation” of the ligands of the asymmetric catalysts, polymers with stereo-block structures can be generated. Generally, the elasticity of these polyolefins mainly comes from the alternately crystallineamorphous block structures, which is closely related to the characteristic of the catalytic system. To improve performance of the catalysts and develop excellent polyolefin elastomers, research on the catalytic mechanism is of great significance. Electron spin resonance (ESR), as a precise method to detect unpaired electron, can be applied to study transition metal active center. Therefore, the progress on the exploration of the valence and the proposed configuration of catalyst active center in the catalytic process by ESR is also reviewed.

APA, Harvard, Vancouver, ISO, and other styles

6

Peng, Wenhao. "High-value recycling and biodegradation of polyolefin materials." Applied and Computational Engineering 23, no. 7 (December 4, 2023): 25–29. http://dx.doi.org/10.54254/2755-2721/23/ojs/20230604.

Full text

Abstract:

The pollution of plastic materials has seriously affected global environmental problems. Polyolefin materials are widely used as raw materials for plastics. This is due to their practical physical properties and low cost. However, there are major challenges in the disposal of waste polyolefin materials. Recycling and degradation have emerged as the two main approaches for the treatment of plastic waste today. Through a comprehensive literature analysis and review of methods, this paper provides an in-depth study of recycling and biodegradation of polyolefin materials. The study is based on a detailed search of several papers through Google Scholar in order to provide valuable insights into the different methods that are used for the recycling and biodegradation of polyolefins. The review summarizes the most effective technologies for recycling and biodegradation, while highlighting recent advances and future directions in the field. In particular, the research has focused on two main approaches: closed-loop recycling and chemical recovery. The latter technology is aimed at non-polluting biodegradation, which has become an increasingly important topic of interest for the scientific community. Given the urgency of the environmental challenges posed by polyolefins, the development of efficient and sustainable recycling and degradation methods is essential to create a circular economy and ensure a sustainable future.

APA, Harvard, Vancouver, ISO, and other styles

7

Peng, Wenhao. "High-value recycling and biodegradation of polyolefin materials." Applied and Computational Engineering 23, no. 1 (November 7, 2023): 25–29. http://dx.doi.org/10.54254/2755-2721/23/20230604.

Full text

Abstract:

The pollution of plastic materials has seriously affected global environmental problems. Polyolefin materials are widely used as raw materials for plastics. This is due to their practical physical properties and low cost. However, there are major challenges in the disposal of waste polyolefin materials. Recycling and degradation have emerged as the two main approaches for the treatment of plastic waste today. Through a comprehensive literature analysis and review of methods, this paper provides an in-depth study of recycling and biodegradation of polyolefin materials. The study is based on a detailed search of several papers through Google Scholar in order to provide valuable insights into the different methods that are used for the recycling and biodegradation of polyolefins. The review summarizes the most effective technologies for recycling and biodegradation, while highlighting recent advances and future directions in the field. In particular, the research has focused on two main approaches: closed-loop recycling and chemical recovery. The latter technology is aimed at non-polluting biodegradation, which has become an increasingly important topic of interest for the scientific community. Given the urgency of the environmental challenges posed by polyolefins, the development of efficient and sustainable recycling and degradation methods is essential to create a circular economy and ensure a sustainable future.

APA, Harvard, Vancouver, ISO, and other styles

8

Pasch, Harald, Lars-Christian Heinz, Tibor Macko, and Wolf Hiller. "High-temperature gradient HPLC and LC-NMR for the analysis of complex polyolefins." Pure and Applied Chemistry 80, no. 8 (January 1, 2008): 1747–62. http://dx.doi.org/10.1351/pac200880081747.

Full text

Abstract:

The synthesis and characterization of polyolefins continues to be one of the most important areas for academic and industrial polymer research. One consequence of the development of new "tailor-made" polyolefins is the need for new and improved analytical techniques for the analysis of polyolefins with respect to molar mass and chemical composition distribution. The present article briefly reviews different new and relevant techniques for polyolefin analysis. Crystallization analysis fractionation is a powerful new technique for the analysis of short-chain branching in linear low-density polyethylene (LLDPE) and the analysis of polyolefin blends and copolymers regarding chemical composition. For the fast analysis of the chemical composition distribution, a new high-temperature gradient high-performance liquid chromatography (HPLC) system has been developed. The efficiency of this system for the separation of various olefin copolymers is demonstrated. The correlation between molar mass and chemical composition can be accessed by on-line coupling of high-temperature size exclusion chromatography (HT-SEC) and 1H NMR spectroscopy. It is shown that the on-line NMR analysis of chromatographic fractions yields information on microstructure and tacticity in addition to molar mass and copolymer composition.

APA, Harvard, Vancouver, ISO, and other styles

9

Tumasev, R. V., O. A. Arkatov, M. A. Goryaynov, V. K. Dudchenko, E. A. Mayer, and A. N. Pestryakov. "Modernization of Technology and Organization of Production of Triethylaluminium Co-Catalyst for Olefin Polymerization." Advanced Materials Research 772 (September 2013): 15–19. http://dx.doi.org/10.4028/www.scientific.net/amr.772.15.

Full text

Abstract:

Actual and prospective Russian market of polyolefins is analyzed. Growth of polyolefin capacities and triethylaluminium consumption as co-catalyst with Ti-Mg catalysts for polypropylene production in Russian Federation is shown. Quality of Russian and foreign triethylaluminium is compared. Project of modernization of TEA installation at Tomskneftekhim LTD is presented.

APA, Harvard, Vancouver, ISO, and other styles

10

Shi, Bo, and Mike Shlepr. "Thermoplastic films containing lignin and their optical polarization properties." Journal of Polymer Engineering 36, no. 5 (July 1, 2016): 521–28. http://dx.doi.org/10.1515/polyeng-2015-0052.

Full text

Abstract:

Abstract A soda lignin, Protobind 2400, was blended at ratios up to thirty weight percent with polyolefins or the aliphatic-aromatic copolyester Ecoflex and films were cast with a twin-screw extruder. The mechanical properties, structure, and optical properties of the resultant films were characterized by tensile tests and microscopy. Films for all blends of this modified lignin were successfully cast without operational issues. Film elongation was maintained for both the polyolefins and Ecoflex. Lignin significantly increased the modulus of the polyethylene films but decreased the modulus of the polypropylene and Ecoflex films. Lignin was found as lamellae oriented in the machine direction of the polyolefin films, but as spherical domains in the Ecoflex film. It was concluded that the oriented lamellar structure was critical to the behavior of the polyolefin-lignin blends as optical polarization films (OPFs). Additional development around improvement of this property, which for the prototypes produced here was about one-tenth the efficiency of commercially available OPFs, to produce a sustainable OPF was recommended.

APA, Harvard, Vancouver, ISO, and other styles

11

Deng, Huiyun, Handou Zheng, Heng Gao, Lixia Pei, and Haiyang Gao. "Late Transition Metal Catalysts with Chelating Amines for Olefin Polymerization." Catalysts 12, no. 9 (August 24, 2022): 936. http://dx.doi.org/10.3390/catal12090936.

Full text

Abstract:

Polyolefins are the most consumed polymeric materials extensively used in our daily life and are usually generated by coordination polymerization in the polyolefin industry. Olefin polymerization catalysts containing transition metal–organic compound combinations are undoubtedly crucial for the development of the polyolefin industry. The nitrogen donor atom has attracted considerable interest and is widely used in combination with the transition metal for the fine-tuning of the chemical environment around the metal center. In addition to widely reported olefin polymerization catalysts with imine and amide donors (sp2 hybrid N), late transition metal catalysts with chelating amine donors (sp3 hybrid N) for olefin polymerization have never been reviewed. In this review paper, we focus on late transition metal (Ni, Pd, Fe, and Co) catalysts with chelating amines for olefin polymerization. A variety of late transition metal catalysts bearing different neutral amine donors are surveyed for olefin polymerization, including amine–imine, amine–pyridine, α-diamine, and [N, N, N] tridentate ligands with amine donors. The relationship between catalyst structure and catalytic performance is also encompassed. This review aims to promote the design of late transition metal catalysts with unique chelating amine donors for the development of high-performance polyolefin materials.

APA, Harvard, Vancouver, ISO, and other styles

12

Kowalska, Ewa. "Mechanical Properties of Rubber Scrap – Polyolefine Compositions." Progress in Rubber, Plastics and Recycling Technology 18, no. 3 (August 2002): 173–93. http://dx.doi.org/10.1177/147776060201800303.

Full text

Abstract:

The mechanical properties and the structure of sections of specimens prepared from rubber scrap – polyolefin compositions were investigated. The comminuted vulcanised rubber scrap rubber scrap was used in an amount of 5 – 75 wt%. The mode of incorporation and the method of preparation of the composition in a single-screw or a twin screw extruder, was examined. The maximum amount of the rubber scrap that can be added to compositions prepared by single screw extruder and a twin screw extruder was found to be up to 75 wt% and up to 30 wt% and for both polyolefins, respectively. Silanes were studied as additives intended to compatibilize thermoplastics and rubber scrap. The mode of incorporation of silanes and the method of preparation of the composition were examined. The mechanism of formation of rubber scrap – polyolefin compositions was defined.

APA, Harvard, Vancouver, ISO, and other styles

13

Nifant’ev, Ilya E., Pavel D. Komarov, Oksana D. Kostomarova, Nikolay A. Kolosov, and Pavel V. Ivchenko. "MAO- and Borate-Free Activating Supports for Group 4 Metallocene and Post-Metallocene Catalysts of α-Olefin Polymerization and Oligomerization." Polymers 15, no. 14 (July 19, 2023): 3095. http://dx.doi.org/10.3390/polym15143095.

Full text

Abstract:

Modern industry of advanced polyolefins extensively uses Group 4 metallocene and post-metallocene catalysts. High-throughput polyolefin technologies demand the use of heterogeneous catalysts with a given particle size and morphology, high thermal stability, and controlled productivity. Conventional Group 4 metal single-site heterogeneous catalysts require the use of high-cost methylalumoxane (MAO) or perfluoroaryl borate activators. However, a number of inorganic phases, containing highly acidic Lewis and Brønsted sites, are able to activate Group 4 metal pre-catalysts using low-cost and affordable alkylaluminums. In the present review, we gathered comprehensive information on MAO- and borate-free activating supports of different types and discussed the surface nature and chemistry of these phases, examples of their use in the polymerization of ethylene and α-olefins, and prospects of the further development for applications in the polyolefin industry.

APA, Harvard, Vancouver, ISO, and other styles

14

ALLAHVERDIYEVA, KH V., N. T. KAKHRAMANOV, M. I. ABDULLIN, L. KH KHAMEDOVA, and S. S. ALIYEVA. "Physicomechanical properties of nanocomposites based on a mixture of graphite, technical carbon, and metal-filled polyolefins." Plasticheskie massy 1, no. 1-2 (March 31, 2022): 37–40. http://dx.doi.org/10.35164/0554-2901-2022-1-2-37-40.

Full text

Abstract:

The paper presents the results of a study of the effect of the concentration of graphite, technical carbon, aluminum and copper on the physicomechanical properties of nanocomposites based on polyolefins. High-density polyethylene, low-density polyethylene and polypropylene were used as polyolefin. To improve the technological compatibility of the mixed components of the mixture, compatibilizers were used, which are copolymers of polyethylene and polypropylene with maleic anhydride.

APA, Harvard, Vancouver, ISO, and other styles

15

Kranzinger, Lukas, Roland Pomberger, Daniel Schwabl, Helmut Flachberger, Markus Bauer, Markus Lehner, and Wolfgang Hofer. "Output-oriented analysis of the wet mechanical processing of polyolefin-rich waste for feedstock recycling." Waste Management & Research: The Journal for a Sustainable Circular Economy 36, no. 5 (March 24, 2018): 445–53. http://dx.doi.org/10.1177/0734242x18764294.

Full text

Abstract:

In recent years, an increasing number of studies have revealed that plastics and their components (e.g. plasticisers) pose an environmental risk. However, it is hard to imagine how our industrialised society could do without these materials, since the fields of application are manifold. One possible approach to tackle this mounting problem is the implementation of a comprehensive and well-functioning collection and recycling system. An international comparison shows that only a small proportion of the total plastics in circulation is collected and recycled. The investigations conducted under the present research project, ‘Plastic Reborn’, focused on both identification and analysis of the discharge paths of polyolefin-rich waste streams, under the Austrian waste management system. Another objective was determining the utilisation potential of the output fractions of these polyolefin-rich waste streams, generated from a wet mechanical processing pilot plant. Experiments have shown that the polyolefins are successfully separated from the waste streams and that a total polyolefin potential of 429,000 t y−1 remains unexploited in the Austrian waste management system. Thus, these separated plastic fractions can make a significant contribution to the implementation of the European Circular Economy Directive. The residual fractions meet the legal and company-specific requirements for their use as solid recovered fuels in co-combustion plants.

APA, Harvard, Vancouver, ISO, and other styles

16

Najaf Kakhramanov, Najaf Kakhramanov, Khayala Allakhverdiyeva Khayala Allakhverdiyeva, Qalina Martynova Qalina Martynova, Fatima Mustafayeva Fatima Mustafayeva, Yunis Kahramanli Yunis Kahramanli, Nazim Sadikhov Nazim Sadikhov, and Azer Amirov Azer Amirov. "New Approaches for the Interpretation of the Structure and Phase Transitions in Nanocomposites Based on Modified Polyolefins and Technical Carbon." Journal of the chemical society of pakistan 45, no. 2 (2023): 119. http://dx.doi.org/10.52568/0012142/jcsp/45.02.2023.

Full text

Abstract:

The results of the investigation of the thermomechanical characteristics of maleinized polyolefine-based nanocomposite materials with different carbon black content are presented. The high density polyethylene, low density polyethylene and polypropylene were used as polyolefins. Highly structured amorphous carbon black of the Printex XE 2B brand with a nanoparticle size of 20 nm, introduced into the composition of the polyolefin in an amount of 1.0–20 wt%, was used as technical carbon. To improve the compatibility of polyolefins with technical carbon, a compatibilizer was used – high-density polyethylene graft copolymer with 5-6 wt% maleic anhydride (PEMA) brand Exxelor PO1040 and polypropylene graft copolymer with 5-6 wt% maleic anhydride (PPMA) brand Exxelor PO1020. The compatibilizer was introduced into the composition of polyolefins in the amount of 2.0 wt%. An electron microscopic, derivatographic and X-ray diffraction analysis of nanocomposites with different technical carbon content was carried out. Thermomechanical studies were carried out on a Kanavets instrument. It was found that with an increase in the content of technical carbon within 1.0, 5.0, 10, 20 wt%, the regularity of change in the thermomechanical curves undergoes significant changes. At a technical carbon concentration of 10 and 20 wt%, an area as a plateau appears on the thermomechanical curves. The most thermally stable plateau appeared for nanocomposites based on maleized LDPE* and PP* with 20 wt% technical carbon content. New scientific approaches are presented for interpreting the discovered regularities, taking into account modern theoretical concepts of the supramolecular crystal structure of nanocomposites and the interfacial amorphous region.

APA, Harvard, Vancouver, ISO, and other styles

17

Motha, Kshama, Ulla Hippi, Kimmo Hakala, Maija Peltonen, Vuokko Ojanperä, Barbro Löfgren, and Jukka Seppälä. "Metallocene-based functionalized polyolefins as compatibilizers in polyolefin nanocomposites." Journal of Applied Polymer Science 94, no. 3 (August 31, 2004): 1094–100. http://dx.doi.org/10.1002/app.20977.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Eaves, David. "The Properties of Crosslinked Foams Produced from Metallocene Polyolefins." Engineering Plastics 5, no. 7 (January 1997): 147823919700500. http://dx.doi.org/10.1177/147823919700500702.

Full text

Abstract:

A unique foaming process is briefly described and the properties of polyolefin foams produced by this process are reviewed. The influence of parameters such as foam density, crosslink level and cell structure are discussed, and in particular the effect of polymer type is examined. Foam grades based on metallocene polyolefins have recently been introduced, and the properties of these materials are compared with those of foams based on other polymers.

APA, Harvard, Vancouver, ISO, and other styles

19

Eaves, David. "The Properties of Crosslinked Foams Produced from Metallocene Polyolefins." Polymers and Polymer Composites 5, no. 7 (January 1997): 477–82. http://dx.doi.org/10.1177/096739119700500702.

Full text

Abstract:

A unique foaming process is briefly described and the properties of polyolefin foams produced by this process are reviewed. The influence of parameters such as foam density, crosslink level and cell structure are discussed, and in particular the effect of polymer type is examined. Foam grades based on metallocene polyolefins have recently been introduced, and the properties of these materials are compared with those of foams based on other polymers.

APA, Harvard, Vancouver, ISO, and other styles

20

Silva-Vela, Alejandro, Francine Roudet, Nataly Calderón, Paul Huanca-Zuñiga, Danny Tupayachy-Quispe, and Jonathan Almirón. "Study of the Mechanical Properties of Polymer Composites Based on Polyolefins with the Addition of Rice Husk and Compatibilizer." Materials Science Forum 1053 (February 17, 2022): 9–15. http://dx.doi.org/10.4028/p-804xor.

Full text

Abstract:

The present work studies the mechanical behavior of rice husk as a reinforcement element in mixtures of polyolefins. The composites were made by polyolefin mixtures of 30% LDPE, 40% HDPE and 30% PP, rice husk and Polybond as a compatibilizer. Samples for the tensile test were prepared by injection and compressive methods. The results confirm that rice husk alongside the compatibilizer bring about positively in the strength of composites. In reference to the adherence of rice husk to the mixture of polyolefins, which was studied from the microstructure of composites, the addition of compatibilizer improves the adherence between the polyolefins and rice husk, and thereby the quality in the fracture surface. These composites are considered to be a good alternative for the recovery of plastic agricultural waste.

APA, Harvard, Vancouver, ISO, and other styles

21

Feigelshtein, Diana, Hannah Harel, Arnold Lustiger, and Gad Marom. "Chopped Polyethylene Fibre Reinforced Ethylene-Butene Copolymers." Advanced Composites Letters 9, no. 5 (September 2000): 096369350000900. http://dx.doi.org/10.1177/096369350000900505.

Full text

Abstract:

This study verifies the option to process chopped polyethylene fibre reinforced polyolefins without causing fibre relaxation. It generates a new family of materials whose property range is as wide as the number of combinations of matrix choice and fibre content. The generic effect of the fibre on the mechanical properties is to turn a soft polyolefin matrix, characterised by low modulus and yield stress and high ductility, into a rigid, high strength composite material.

APA, Harvard, Vancouver, ISO, and other styles

22

Mittal, Vikas. "Modeling of Tensile Modulus of Polyolefin-Layered Silicate Nanocomposites: Modified Halpin Tsai Models." Advanced Composites Letters 21, no. 5 (September 2012): 096369351202100. http://dx.doi.org/10.1177/096369351202100501.

Full text

Abstract:

The modified forms of Halpin Tsai model for the prediction of tensile modulus of polyolefin-layered silicate nanocomposites are discussed. The assumptions used in the conventional model like perfect alignment of the particulate filler, uniform shape and size of the filler particles as well as interfacial adhesion between the polymer and filler surface do not hold true in the case of polymer nanocomposites especially using polyolefinic matrices. The modulus reduction factors suggested for polar nanocomposites are also dependent on the polymer nature as well as filler morphology in the composite, thus, are not applicable directly to the polyolefin composites. A master curve could be generated for polyolefin nanocomposites which provided more accurate modulus reduction factor value based on the average aspect ratio of the filler. Incorporation of the effects of incomplete exfoliation as well as filler misalignment though improved the prediction capabilities of the model, however, it still did not match the predictions generated from finite element analysis or TEM analysis. The effect of absence of adhesion forces at the interface was incorporated by suggesting simple modification to the modified Halpin Tsai model equation. Master curves could be generated which predicted the relative tensile modulus of the composites accurately if the value of average aspect ratio was known.

APA, Harvard, Vancouver, ISO, and other styles

23

Feldman, Dorel. "Polyolefin, olefin copolymers and polyolefin polyblend nanocomposites." Journal of Macromolecular Science, Part A 53, no. 10 (September 3, 2016): 651–58. http://dx.doi.org/10.1080/10601325.2016.1212313.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Charfeddine, Ilhem, Jean‐Charles Majesté, Christian Carrot, and Olivier Lhost. "Surface tension and interfacial tension of polyolefins and polyolefin blends." Journal of Applied Polymer Science 139, no. 14 (November 11, 2021): 51885. http://dx.doi.org/10.1002/app.51885.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Hasegawa, Naoki, Hirotaka Okamoto, Masaya Kawasumi, Makoto Kato, Azusa Tsukigase, and Arimistu Usuki. "Polyolefin-clay hybrids based on modified polyolefins and organophilic clay." Macromolecular Materials and Engineering 280-281, no. 1 (August 1, 2000): 76–79. http://dx.doi.org/10.1002/1439-2054(20000801)280:1<76::aid-mame76>3.0.co;2-#.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Ye, Zhen, and Yuechao Zhao. "Polyolefin Elastomer Modified Asphalt: Performance Characterization and Modification Mechanism." Buildings 13, no. 5 (May 16, 2023): 1291. http://dx.doi.org/10.3390/buildings13051291.

Full text

Abstract:

The rapid growth of traffic load and volume has put forward higher requirements for road durability. To extend the service life of roads, this work investigated the feasibility of using polyolefin elastomers with a two-phase molecular structure to simultaneously improve the high and low-temperature performance of asphalt. The characteristics of the polyolefin modifier were evaluated by differential scanning calorimetry first. Following evaluation, the storage stability, workability, and rheological properties of modified polyolefin-modified asphalt were measured through softening point difference, rotary viscosity, dynamic shear rheometer, and bending beam rheometer. Additionally, the engineering performance of modified asphalt mixtures was also investigated through Marshall stability, wheel-tracking, and three points bending experiments. The results show that polyolefin has two glass transition points which facilitate the simultaneous improvement of the high and low-temperature properties of asphalt. Meanwhile, no concerns are found about the storage stability and workability of polyolefin-modified asphalt. Furthermore, the results of rheological properties indicate that polyolefin can significantly enhance the deformation resistance at high-temperature and cracking resistance at low-temperature of asphalt binders. While the fatigue performance of the polyolefin-modified asphalt is slightly reduced, the residual Marshall stability, dynamic stability, and ultimate tensile strain of the asphalt mixture containing 8% polyolefin are 1.05 times, 1.31 times, and 1.17 times those of the control sample, respectively. The results of infrared spectroscopy demonstrate that there is no chemical reaction between the polyolefin-modified and the virgin asphalt. The improvement of polyolefin on asphalt performance can be explained by the existence of both “rigid” and “flexible” structures in polyolefin.

APA, Harvard, Vancouver, ISO, and other styles

27

Zaikov, G. E., K. Z. Gumargalieva, A. Ya Polishchuk, A. A. Adamyan, and T. I. Vinokurova. "Polyolefin Biodegradation." International Journal of Polymeric Materials 44, no. 1-2 (August 1999): 107–33. http://dx.doi.org/10.1080/00914039908012139.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

RITTER, STEVE. "POLYOLEFIN SHUFFLE." Chemical & Engineering News 84, no. 19 (May 8, 2006): 9. http://dx.doi.org/10.1021/cen-v084n019.p009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

KRIEGER, JAMES. "POLYOLEFIN TECHNOLOGY." Chemical & Engineering News 72, no. 21 (May 23, 1994): 6–7. http://dx.doi.org/10.1021/cen-v072n021.p006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Greco, R., E. Martuscelli, G. Ragosta, and Yin Jinghua. "Polyolefin blends." Journal of Materials Science 23, no. 12 (December 1988): 4307–14. http://dx.doi.org/10.1007/bf00551924.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Denchev, Zlatan Z. "Polyolefin Blends." Macromolecular Materials and Engineering 293, no. 7 (June 3, 2008): 641. http://dx.doi.org/10.1002/mame.200800108.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Liauw, Christopher Mark. "Polyolefin Composites." Macromolecular Materials and Engineering 294, no. 5 (May 6, 2009): 352. http://dx.doi.org/10.1002/mame.200900085.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Kresge, E. N., D. J. Lohse, and S. Datta. "Polyolefin blends." Makromolekulare Chemie. Macromolecular Symposia 53, no. 1 (January 1992): 173–89. http://dx.doi.org/10.1002/masy.19920530117.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Zhao, Yucheng, Emma M. Rettner, Katherine L. Harry, Zhitao Hu, Joel Miscall, Nicholas A. Rorrer, and Garret M. Miyake. "Chemically recyclable polyolefin-like multiblock polymers." Science 382, no. 6668 (October 20, 2023): 310–14. http://dx.doi.org/10.1126/science.adh3353.

Full text

Abstract:

Polyolefins are the most important and largest volume plastics produced. Unfortunately, the enormous use of plastics and lack of effective disposal or recycling options have created a plastic waste catastrophe. In this work, we report an approach to create chemically recyclable polyolefin-like materials with diverse mechanical properties through the construction of multiblock polymers from hard and soft oligomeric building blocks synthesized with ruthenium-mediated ring-opening metathesis polymerization of cyclooctenes. The multiblock polymers exhibit broad mechanical properties, spanning elastomers to plastomers to thermoplastics, while integrating a high melting transition temperature ( T m ) and low glass transition temperature ( T g ), making them suitable for use across diverse applications ( T m as high as 128°C and T g as low as –60°C). After use, the different plastics can be combined and efficiently deconstructed back to the fundamental hard and soft building blocks for separation and repolymerization to realize a closed-loop recycling process.

APA, Harvard, Vancouver, ISO, and other styles

35

Pop-Iliev, Remon. "Foaming Ability of Rotomolding Polyolefin Resins." Advanced Materials Research 875-877 (February 2014): 1560–64. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.1560.

Full text

Abstract:

The main focus of the research presented in this paper is the investigation of the ability of various polyolefin resins to be converted into integral-skin cellular composites by using the rotational foam molding process. Integral-skin foamed rotational moldings are formally denoted as cellular composites ideally having a clearly distinct surface layer of solid skin of uniform thickness that is encapsulating a seamlessly coupled fine-celled foamed core or layer of uniform cell density and distribution. A systematic comparative material characterization study that attempts to derive practical guidelines about determining the roto-foamability of polyolefins that would be useful for rotomolding processors is presented. The study included two experimental methods of characterization, a melt rheology-based and a rotational foam molding processing-based. The experimental results from both implemented characterization methods revealed good agreement. A comprehensive insight into the key polyolefin material characteristics that would ensure satisfactory results if processed using the rotational foam molding technology have been provided. The experimental results revealed that high quality polyethylene (PE) based cellular morphologies can be obtained from both dry blended and melt compounded foamable compositions for both 6-fold and 3-fold expanded foams. Unlike PE resins, it was observed that successful foaming of polypropylene (PP) resins in rotational foam molding can only be successfully accomplished over a very narrow range of melt temperatures that are close to the melting point of the polymer and by using PP grades with a quite limited range of Melt Flow Rates (MFR).

APA, Harvard, Vancouver, ISO, and other styles

36

Kim, Tae Jin, Jun Won Baek, Seung Hyun Moon, Hyun Ju Lee, Kyung Lee Park, Sung Moon Bae, Jong Chul Lee, Pyung Cheon Lee, and Bun Yeoul Lee. "Polystyrene Chain Growth Initiated from Dialkylzinc for Synthesis of Polyolefin-Polystyrene Block Copolymers." Polymers 12, no. 3 (March 2, 2020): 537. http://dx.doi.org/10.3390/polym12030537.

Full text

Abstract:

Polyolefins (POs) are the most abundant polymers. However, synthesis of PO-based block copolymers has only rarely been achieved. We aimed to synthesize various PO-based block copolymers by coordinative chain transfer polymerization (CCTP) followed by anionic polymerization in one-pot via conversion of the CCTP product (polyolefinyl)2Zn to polyolefinyl-Li. The addition of 2 equiv t-BuLi to (1-octyl)2Zn (a model compound of (polyolefinyl)2Zn) and selective removal or decomposition of (tBu)2Zn by evacuation or heating at 130 °C afforded 1-octyl-Li. Attempts to convert (polyolefinyl)2Zn to polyolefinyl-Li were unsuccessful. However, polystyrene (PS) chains were efficiently grown from (polyolefinyl)2Zn; the addition of styrene monomers after treatment with t-BuLi and pentamethyldiethylenetriamine (PMDTA) in the presence of residual olefin monomers afforded PO-block-PSs. Organolithium species that might be generated in the pot of t-BuLi, PMDTA, and olefin monomers, i.e., [Me2NCH2CH2N(Me)CH2CH2N(Me)CH2Li, Me2NCH2CH2N(Me)Li·(PMDTA), pentylallyl-Li⋅(PMDTA)], as well as PhLi⋅(PMDTA), were screened as initiators to grow PS chains from (1-hexyl)2Zn, as well as from (polyolefinyl)2Zn. Pentylallyl-Li⋅(PMDTA) was the best initiator. The Mn values increased substantially after the styrene polymerization with some generation of homo-PSs (27–29%). The Mn values of the extracted homo-PS suggested that PS chains were grown mainly from polyolefinyl groups in [(polyolefinyl)2(pentylallyl)Zn]−[Li⋅(PMDTA)]+ formed by pentylallyl-Li⋅(PMDTA) acting onto (polyolefinyl)2Zn.

APA, Harvard, Vancouver, ISO, and other styles

37

SAITO, Junji, Nobuo KAWAHARA, Shingo MATSUO, Hideyuki KANEKO, Tomoaki MATSUGI, and Norio KASHIWA. "Syntheses, Structures and Functions of Polyolefin/non-Polyolefin Hybrids." KOBUNSHI RONBUNSHU 64, no. 12 (2007): 897–906. http://dx.doi.org/10.1295/koron.64.897.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Nifant’ev, Ilya E., Alexander N. Tavtorkin, Alexey A. Vinogradov, Sofia A. Korchagina, Maria S. Chinova, Roman S. Borisov, Grigory A. Artem’ev, and Pavel V. Ivchenko. "Tandem Synthesis of Ultra-High Molecular Weight Drag Reducing Poly-α-Olefins for Low-Temperature Pipeline Transportation." Polymers 13, no. 22 (November 14, 2021): 3930. http://dx.doi.org/10.3390/polym13223930.

Full text

Abstract:

Ultra-high molecular weight poly-α-olefins are widely used as drag reducing agents (DRAs) for pipeline transportation of oil and refined petroleum products. The synthesis of polyolefin DRAs is based on low-temperature Ziegler–Natta (ZN) polymerization of higher α-olefins. 1-Hexene based DRAs, the most effective at room temperature, typically lose DR activity at low temperatures. The use of 1-hexene copolymers with C8–C12 linear α-olefins appears to offer a solution to the problem of low-temperature drag reducing. The present work aims to develop two-stage synthesis of polyolefin DRAs that is based on selective oligomerization of ethylene in the presence of efficient chromium/aminodiphosphine catalysts (Cr-PNP), followed by polymerization of the olefin mixtures, formed at oligomerization stage, using efficient titanium–magnesium ZN catalyst. We have shown that oligomerization of ethylene in α-olefin reaction media proceeds faster than in saturated hydrocarbons, providing the formation of 1-hexene, 1-octene, and branched C10 and C12 olefins; the composition and the ratio of the reaction products depended on the nature of PNP ligand. Oligomerizates were used in ZN polymerization ‘as is’, without additional treatment. Due to branched character of C10+ hydrocarbons, formed during oligomerization of ethylene, resulting polyolefins demonstrate higher low-temperature DR efficiency at low polymer concentrations (~1 ppm) in comparison with benchmark polymers prepared from the mixtures of linear α-olefins and from pure 1-hexene. We assume that faster solubility and more efficient solvation of the polyolefins, prepared using ‘tandem’ ethylene-based process, represent an advantage of these type polymers over conventional poly(1-hexene) and linear α-olefin-based polymers when used as ‘winter’ DRAs.

APA, Harvard, Vancouver, ISO, and other styles

39

Bogdan, O. P., D. V. Zlobin, O. V. Murav'eva, S. M. Molin, and A. V. Platunov. "Evaluation of Nonuniformity of Elastic Properties of Sheets Made from Closed-Сell Polyolefin Foams by Acoustic Method." Devices and Methods of Measurements 12, no. 1 (March 19, 2021): 58–66. http://dx.doi.org/10.21122/2220-9506-2021-12-1-58-66.

Full text

Abstract:

The widespread use of polyolefin foams in strategically important industries is due to their high thermal, sound and vibration insulation properties. The aim of the work was to evaluate the non-uniformity of elastic properties over the area of sheets of polyolefin foams of various types using the acoustic non-contact shadow amplitude method of testing and confirmation by the structural analysis method.The article presents the developed installation and a new method of non-contact acoustic testing of sheets made of closed-cell polyolefin foams based on recording the amplitude of the pulse that passed through the sheet and allowing to assess to the unevenness of its elastic properties during scanning. Studies of uneven elastic properties were carried out on sheets of closed-cell polyolefin foams of the ISOLON 500 and ISOLON 300 brands which differ in material and manufacturing technology (technique of cross-linking, method and multiplicity of foaming).It is shown that the absolute amplitude of the signal and its spread relative to the average value is affected by the structure of the foam polyolefin material and its heterogeneity over the area of the studied sheet determined by the production technology which is confirmed visually using microscopy.Studies have shown the effect on the indications unevenness of the method of obtaining and the apparent density of the material. It is shown that the most uneven elastic properties and structure belong to sheets of polyolefin foam obtained by chemical cross-linking technology (the unevenness of Δ was 6.5 %). Among the physically cross-linked sheets of polyolefin foam the most uniform in structure and elastic properties are samples made of ethylene vinyl acetate with Δ = 3.8 %, as well as sheets with a high foaming rate (Δ = 3.9 %). The unevenness of structure of the studied sheets of polyolefin foams was confirmed by optical microscopy of sections in two mutually perpendicular directions.

APA, Harvard, Vancouver, ISO, and other styles

40

Schwabl, Daniel, Markus Bauer, and Markus Lehner. "Advancing Plastic Recycling by Wet-Mechanical Processing of Mixed Waste Fractions." Processes 9, no. 3 (March 9, 2021): 493. http://dx.doi.org/10.3390/pr9030493.

Full text

Abstract:

In this paper, an arc was drawn over ten years of research activities from three chairs of the Montanuniversitaet Leoben, as well as industrial partners. The superior objective of this research effort was to develop a wet-mechanical process for the recovery of polyolefin concentrates (90 wt% polyolefins) from mixed waste fraction for use in chemical recycling and to advance this new technology to commercial maturity. As a bridge technology, it would close the gap between state-of-the-art dry processing of mixed plastic waste materials and chemical plastic recycling via thermo-chemical conversion. The methods used were mainly tested in a lab-scale plant with a throughput capacity of 50 to 200 kg/h depending on the bulk density of the used feedstock. Further studies for the treatment and usage of the main products and by-products, as well as chemical analyses of them, were completed during the investigation. Within these series of tests, polyolefin concentrates, which satisfied the requirements for chemical recycling, could be recovered. With these data, a concept for an industrial pilot plant was developed and evaluated from an economic point of view. According to this evaluation, the realization of such an industrial pilot plant can be recommended.

APA, Harvard, Vancouver, ISO, and other styles

41

Sultana, S. M. Nourin, Emna Helal, Giovanna Gutiérrez, Eric David, Nima Moghimian, and Nicole R. Demarquette. "The Influence of a Commercial Few-Layer Graphene on the Photodegradation Resistance of a Waste Polyolefins Stream and Prime Polyolefin Blends." Recycling 9, no. 2 (April 9, 2024): 29. http://dx.doi.org/10.3390/recycling9020029.

Full text

Abstract:

This work investigated the photostabilizing role of a commercially available few-layer graphene (FLG) in mixed polyolefins waste stream (MPWS), ensuring extended lifespan for outdoor applications. The investigation was conducted by analyzing carbonyl content increase, surface appearance, and the retention of mechanical properties of UV-exposed MPWS/FLG composites. Despite the likely predegraded condition of MPWS, approximately 60%, 70%, 80%, and 90% of the original ductility was retained in composites containing 1, 4, 7, and 10 wt.% FLG, respectively. Conversely, just 20% of the original ductility was retained in unfilled MPWS. Additionally, less crack density and lower carbonyl concentrations of the composites also highlighted the photoprotection effect of FLG. For prime polyolefin blends, only 0.5 wt.% or 1 wt.% FLG was sufficient to preserve the original surface finishing and protect the mechanical properties from photodegradation. Hence, it was observed that MPWS requires more FLG than prime polyolefin blends to get to comparable property retention. This could be attributed to the poor dispersion of FLG in MPWS and inevitable uncertainties such as the presence of impurities, pre-degradation, and polydispersity associated with MPWS. This study outlines a potential approach to revalorize MPWS that possess a minimal intrinsic value and would otherwise be destined for landfill disposal.

APA, Harvard, Vancouver, ISO, and other styles

42

Kim, Dong Hyun, Seung Soo Park, Su Hyun Park, Jong Yeob Jeon, Hyo Bo Kim, and Bun Yeoul Lee. "Preparation of polystyrene–polyolefin multiblock copolymers by sequential coordination and anionic polymerization." RSC Advances 7, no. 10 (2017): 5948–56. http://dx.doi.org/10.1039/c6ra25848d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Matuana, L. M., S. Cam, K. B. Yuhasz, and Q. J. Armstrong. "Composites of Acrylonitrile-Butadiene-Styrene Filled with Wood-Flour." Polymers and Polymer Composites 15, no. 5 (July 2007): 365–70. http://dx.doi.org/10.1177/096739110701500503.

Full text

Abstract:

This study examined both the use of acrylonitrile-butadiene-styrene (ABS) as a plastic matrix for wood-plastic composites (WPCs) and the effect of impact modification on the mechanical properties of ABS/wood-flour composites. Blends of ABS filled with wood flour (both pine and maple) were processed into profile shape using a conical twin-screw extruder and the mechanical properties of the resulting composites were characterised and compared to WPCs made with polyolefins (HDPE and PP) and rigid PVC matrices. Generally, WPCs made with ABS matrix outperformed their polyolefin counterparts in both flexural strength and modulus, whereas ABS-based composites had inferior strength but greater modulus than those made with rigid PVC. The impact strength of ABS/wood-flour composites was below that of wood plastic composites made with polyolefins. However, impact modification with acrylonitrile-butadiene-styrene terpolymers had some effect in toughening of the ABS/wood-flour composites.

APA, Harvard, Vancouver, ISO, and other styles

44

Prashantha, K., J. Soulestin, M. F. Lacrampe, and P. Krawczak. "Present Status and Key Challenges of Carbon Nanotubes Reinforced Polyolefins: A Review on Nanocomposites Manufacturing and Performance Issues." Polymers and Polymer Composites 17, no. 4 (May 2009): 205–45. http://dx.doi.org/10.1177/096739110901700402.

Full text

Abstract:

Carbon nanotube reinforcement is a key emerging technology to simultaneously impart enhanced mechanical properties while adding multifunctional characteristics to polymer materials and systems. The promise of extraordinary improvement in-end use properties of polyolefin/carbon nanotube hybrid systems has spurred great interest and intensive activity in academics and industries. This review offers a comprehensive discussion of the preparation, compounding, properties and applications of such nanocomposites. The processing, dispersion and orientation of nanotubes, as well as the characterisation of physical and mechanical properties of carbon nanotube filled polyolefins are discussed. In particular the scientific principles and mechanisms in relation to the methods of manufacturing are highlighted, with an outlook towards commercial applications.

APA, Harvard, Vancouver, ISO, and other styles

45

Jeong, Boo Young, Min Ji Choi, Won-Ki Lee, Jae Hwan Chun, Jung Mi Cheon, and Chang-Sik Ha. "Preliminary studies of polyurethane adhesive for thermoplastic polyolefins(TPOs) using polyolefin polyol." Molecular Crystals and Liquid Crystals 660, no. 1 (January 2, 2018): 115–20. http://dx.doi.org/10.1080/15421406.2018.1456102.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Scoponi, Marco, Fiorella Pradella, and Vittorio Carassiti. "Photodegradable polyolefins. Photo-oxidation mechanisms of innovative polyolefin copolymers containing double bonds." Coordination Chemistry Reviews 125, no. 1-2 (May 1993): 219–30. http://dx.doi.org/10.1016/0010-8545(93)85019-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Libert, D., and A. Wyart. "Polyolefin molding compositions." Zeolites 18, no. 1 (January 1997): 92. http://dx.doi.org/10.1016/s0144-2449(97)85047-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Jenny, Charles, and Peter Maddox. "Supported polyolefin catalysts." Current Opinion in Solid State and Materials Science 3, no. 1 (February 1998): 94–103. http://dx.doi.org/10.1016/s1359-0286(98)80071-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Gallati, Hans. "Umweltfreundliche Polyolefin-Schaumstoffe." ATZ - Automobiltechnische Zeitschrift 109, no. 11 (November 2007): 1070–72. http://dx.doi.org/10.1007/bf03221936.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Shitov, D. Yu, T. P. Kravchenko, Yu M. Budnitskii, N. Z. Lin, and V. S. Osipchik. "Polyolefin-Based Nanocomposites." International Polymer Science and Technology 43, no. 6 (June 2016): 27–32. http://dx.doi.org/10.1177/0307174x1604300605.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!