Academic literature on the topic 'UV curable composites'

碩士<br>淡江大學<br>化學學系碩士班<br>103<br>A low surface energy and hydrophobic material, Polydimethylsiloxane (PDMS) has been selected to react with isophorone diisocyanate (IPDI) and forming a NCO-terminated PDMS-containing Polyurethane (PU) prepolymer, it then reacts further with 2-hydroxyethyl methacrylate (HEMA) and results in a formation of acrylate-terminated PDMS-containing PU oligomer. It is compounded with hydrophobic long-chain hydrocarbon (its carbon number more than 16 and that is similar to wax) acrylate (monomer) and becomes UV-curable hydrophobic PU coating material. Nano-particles are generated from a sol-gel process by mixing tetra-ethyl siloxane (TEOS) and 3-(trimethyyloxysilyl)propyl methacrylate (TESPMA) that creates even rough surface and that increases water-resistance on the coated hydrophobic textile surface after UV-curing process. Hydrophobic textile treatment: A refined PET textile (treated with diluted NaOH solution and cleaned with de-ionized water) is treated with UV-curable hydrophobic PU oligomers and cured with UV-radiation or heating. The results of hydrophobic treated textiles are evaluated by AATCC testing methods.

碩士<br>淡江大學<br>化學學系碩士班<br>103<br>Hydrophilic NCO-terminated PU oligomer is obtained from hydrophilic polyethylene glycols-2000(PEG-2000)and dimethylolpropanic acid(DMPA) with isophorone diisocyanate(IPDI). It is reacted further with 3-acryloloxy -2-hydropropyl methacrylate (AHM) and forming UV-curable hydrophilic PU oligomer. DMPA offers COOH hydrophilic center.SiO2/TiO2 hybrids can be formulated within hydrophilic PU oligomers (in situ) before water dispersion. It is dispersed into water phase after neutralized with triethyl amine (TEA) as an aqueous-based dispersion UV-curable hydrophilic PU. This aqueous-based PU includes both thermal curing agent (TMPTA-AZ for ring-opening reaction) and UV-curing recipes (photo-initiator and reactive diluents). Hydrophobic PET textile is treated with aqueous-based dispersion of UV-curable resin and UV-cured with after dry.There are two different curing reactions with this hydrophilic PU coating material taking place: 1. COOH reacts withTMPTA-AZvia a ring-opening reaction.2.UV-curing of acrylated terminal groups PU and reactive diluents.The final cured hydrophilic PU forms inter-penetrating networks (IPN) with PET textile and it results water washing durable hydrophilic textile treatments after 30 washing cycles according to AATCC-135 method. The hydrophilic textile treated with this prepared PU resin,it demonstrate a quick and efficient method to improve the long lasting textile hyrophilicity by thermal and UV-curing dual processes.

碩士<br>淡江大學<br>化學學系碩士班<br>98<br>In this article, two series organic -inorganic nano composites were invetigated and compared with each other. Hybridization of UV-curable Polysiloxane-containg PU composite with surface modified nano-silica particles via glycidyl methacrylate (GMA). A PDMS-containing PU oligomer that is obtained from NCO-terminated PU prepolymer with 2-hydroxyethyl methacrylate. The physical properties (such as gel content, water-uptake, enthanol-uprtake, ect.), the thermal properties (thermalgravimentric analysis and dynamic mechanical analysis), the UV/vis spectra transmittance, and scanning electron microscope (SEM) of the orangic-inorangic nanocomposites were evaluated in this article.

碩士<br>淡江大學<br>化學學系碩士班<br>95<br>In this article, the modification of the aqueous-based polyurethane (PU) is the main target. Firstly, the NCO-terminated aqueous-based PU prepolymer was synthesized from the poly-addition reaction of the diisocyanate (e.g. isophorone diisocyanate, IPDI), polypropylene glycol (PPG) and 2,2’-dimethylolpropanoic acid (DMPA). Following, the 2-hydroxyethyl methacrylate (2-HEMA) was used to react with the NCO-terminated functional groups of the prepolymer to modify it and the UV-curable aqueous-based PU was obtained. The various dosages of nano-Silica (MA-ST, nano-silica with 15 nm diameter and 30 w/w % dispersed in methanol) were hybridized with the UV-curable aqueous-based PU and cured by the UV irradiation to obtain the series of organic/inorganic nano-composites. The physical (such as gel content, water-uptake, solvent resistance, contact angle and etc.), mechanical (such as tensile strength and elongation, Shore-a hardness et al.) and thermal (such as thermogravimetric analysis and dynamic mechanical analysis) properties were evaluated in this article. In addition, the discussion of phase separation was investigated by the scanning electronic microscopy and UV transmittance, in this study.

博士<br>國立交通大學<br>材料科學與工程系所<br>95<br>Preparation and characterizations of the photo-curable organic/inorganic nano-hybrids for OLED packaging are carried out in this study. The experimental works can be classified into two portions: the first is relating to the polymer/clays nanocomposite resins. After clays-modification with synthesized surfactants, the modified clays, or called the acrylateclays were respectively added into photo-curable co-polyacrylate and epoxide resin matrices. The applicability to OLED packaging of epoxide/acrylateclays nanocomposite resin was evaluated by characterizing the lifetime of devices. The second part studies the preparation and characterizations of photo-curable co-polyacrylate/SiO2 nanocomposite material by in-situ sol-gel process. Reliability of OLEDs encapsulated by the co-polyacrylate/SiO2 was also investigated in this part of study so as to evaluate its applicability to OLED packaging. Experimental results revealed that the surfactant synthesis generated five different products. The products containing nitrogen atoms can be acidified and serve as the surfactants to intercalate into clay galleries. It was found that the synthesized surfactants may replace 71.4% of cations in clay lamellas and consequently form the acrylateclays. They effectively enlarged the d-spacing of clay lamellas from 13.6 to 33.2Å according to XRD analysis. The DTG analysis showed that the methylacrylate groups in the synthesized surfactants may react with acrylate/methylacrylate groups in monomers via photo-polymerization process. The photo-crosslinking subsequently promoted the compatibility between organic/inorganic portions. Such an effect led to the formation of nano-scale clay segments with thickness about 60 to 80 nm in co-polyacrylate/acrylateclays resin sample and an intercalated clay structure in epoxide/acrylateclays resin sample, as revealed by the TEM observation. The 5% weight loss temperature (Td) of co-polyacrylate/acrylateclays nanocomposite material was increased up to 16�aC when 5 wt.% of clay was added. The average optical transmittance of co-polyacrylate/acrylateclays resin sample reduced from 88.7% to 76.6% in visible-light wavelength range and the moisture absorption decreased from 3.44% to 1.31%. For epoxide/acrylateclays nanocomposite resin containing 5 wt.% intercalated segments, the Td increased from 149 to 213�aC, the coefficient of thermal expansion (CTE) reduced from 228.9 ppm/�aC to 80.5 ppm/�aC, the average optical transmittance slightly reduced from 86.0% to 83.7%, the moisture absorption decreased from 12.70% to 6.12% and the adhesion strength remained 43.8 kgf/cm2. For the epoxide/acrylateclays nanocomposite applied to OLED packaging, the lifetime of nanocomposite-sealed OLED is two-fold higher than that of acrylate resin-sealed OLEDs. The intercalated clay structure could sufficiently increase the permeation path of moisture, subsequently retarded the degradation of OLEDs. For the photo-curable co-polyacrylate/silica nanocomposite resin containing 10 wt.% nano-sized silica particles, the glass transition temperature (Tg) ascended from 86�aC to 107�aC, the CTE decreased from 99.2 ppm/�aC to 30.6 ppm/�aC, the Td remained 180�aC, the moisture permeability reduced from 13.59 g/m2��24 hrs to 10.41 g/m2��24 hrs, the Young’s modules increased from 9.5 GPa to 265.8 GPa, the adhesion strength improved from 20.2 kgf/cm2 to 42.8 kgf/cm2 and the average optical transmittance changed from 82.3% to 82.0%; besides, at 10 kV/cm its leakage current density greatly diminished from 235 nA/cm2 to 1.3 nA/cm2, the dielectric constant was as low as 3.93 and the tangent loss was 0.0472. By applying co-polyacrylate/silica nanocomposite resin to direct encapsulation of bottom-emitted OLEDs, it found that the curing process did not affect the luminance of encapsulated devices and the device driving voltage decreased from 6.77V to 6.09V due to improved insulation property. Moreover, the lifetime of nanocomposite-encapsulated OLED increased from 178 hrs for resin-encapsulated OLED to 350 hrs for nanocomposite-encapsulated OLED. Experimental analyses indicated that excess UV irradiation may degrade the physical properties of nanocomposite resin such as insulation property and thermal resistance so as to deteriorate the lifetime of devices. Finally, above studies indicate that the dispersion of inorganic fillers and adhesion properties of nanocomposite sealing resins played important roles on the reliability of OLEDs.

碩士<br>中原大學<br>化學研究所<br>106<br>This dissertation is mainly focused on the study of polymer composites containing beads milled waste sawdust and applied in anticorrosion application. First of all, the sawdust obtained from cutting of commercially available solar panels was processed by beads-milled procedure by Zr beads of ~ 5 mm in diameter. Subsequently, the photo-polymerization of styrene monomer in the presence of suitable amount of beads-milled sawdust was performed under UV radiation of exposed wavelength of 365 nm, exposed time of 4 hours, exposed distance of 10 cm. The as-prepared polystyrene (PS)/Si sawdust composites were characterized by Fourier transformation infrared (FTIR) spectroscopy. Morphological dispersion of sawdust in PS was studied by scanning electron microscopy (SEM) and EDX. It should be noted that the PS/Si sawdust composites were found to exhibit better anticorrosion performance as compared to that of neat PS based on a series of electrochemical corrosion measurements in saline conditions. According to the test results, the addition of the micro-slice structure of the Si sawdust can effectively improve the corrosion resistance of polystyrene. The polystyrene added with the Si sawdust has increased from the original corrosion protection efficiency from 58.81% to 93.57%, confirming the addition. Si sawdust can prolong the diffusion path of corrosion factor to achieve anti-corrosion effect. The O2 gas permeability of composite membranes was found to lower than that of neat PS membrane, after adding Si sawdust the penetration rate of polystyrene to oxygen decreased from the original 23.64 g/m2-h to 11.55 g/m2-h, which supports the corresponding data of anticorrosion performance of coatings.

碩士<br>國立臺灣科技大學<br>纖維及高分子研究所<br>86<br>This study concerns a novel process to disperse blue dichroic dyes (M483)in varying concentrations of ferroelectric liquid crystal (CS-1024) to manufature the display device of Dye Guest-Host Ferroelectric Liquid Crystals(DGHFLC)and produce the new type of Dye Guest-Host Polymer DispersedFerroelectric Liquid Crystals (DGHPDFLC) with a single polarizer. The anisotropic absorption effect of the dichroic dye and the characteristics of low threshold voltage, fast switch speed and wide viewingangle of ferroelectric liquid crystals combined with the processibility of thepolymer were used to investigate the performance and the influence of formationconditions on the cure degree of a polymer matrix and the electro-opticproperties of the Polymer/DGHFLC composite film. Formation conditions includedthe intensity of the UV light and the content of the the prepolymer(NOA65). Our main objective was to resolve the problems of traditional FLC and PDFLCliquid crystal displays, such as low brightness, narrow viewing angle and so on.We used the following equipment: polarizing microscope, polarizingmicro-spectrometer, He-Ne laser, arbitrary waveform generator and digitaloscilloscope to study the physical properties of DGHFLC and DGHPDFLC. The results show that both the addition of dye and the content of thepolymer increase the rotational viscosity of the whole mixed system and lowerresponse time. In addition, it rises the bistability and memory effect of DGHFLCand DGHPDFLC much more than those of ferroelectric liquid crystals. For bothcontrast ratio and the rate of transmitted light the DGHPDFLC is better thanDGHFLC. During the measurement of physical properties, the ferroelectric phasetransition temperature tended to go down after the addition of dye during theexperiment. The results could be attributed to the phase equilibrium of thetwo mixed compounds of dye and liquid crystal which induces little change in theliquid crystal phase transition temperature.

<p>The performance of solid rocket motors (SRMs) is extremely dependent on propellant formulation, operating pressure, and initial grain geometry. Traditionally, propellant grains are cast into molds, but it is difficult to remove the grains without damage if the geometry is too complex. Cracks or voids in propellant can lead to erratic burning that can break the grain apart and/or potentially overpressurize the motor. Not only is this dangerous, but the payload could be destroyed or lost. Some geometries (i.e. internal voids or intricate structures) cannot be cast and there is no consistent nor economical way to functionally grade grains made of multiple propellant formulations at fines scales (~ mm) without the risk of delamination between layers or the use of adhesives, which significantly lower performance. If one could manufacture grains in such a way, then one would have more control and flexibility over the design and performance of a SRM. However, new manufacturing techniques are required to enable innovation of new propellant grains and new analysis techniques are necessary to understand the driving forces behind the combustion of non-traditionally manufactured propellant.</p> <p>Additive manufacturing (AM) has been used in many industries to enable rapid prototyping and the construction of complex hierarchal structures. AM of propellant is an emerging research area, but it is still in its infancy since there are some large challenges to overcome. Namely, high performance propellant requires a minimum solids loading in order to combust properly and this translates into mixtures with high viscosities that are difficult to 3D print. In addition, it is important to be able to manufacture realistic propellant formulations into grains that do not deform and can be precisely functionally graded without the presence of defects from the printing process. The research presented in this dissertation identifies the effect of a specific AM process called Vibration Assisted Printing (VAP) on the combustion of propellant, as well as the development of binders that enable UV-curing to improve the final resolution of 3D printed structures. In addition, the combustion dynamics of additively manufactured layered propellant is studied with computational and experimental methods. The work presented in this dissertation lays the foundation for progress in the developing research area of additively manufactured energetic materials. </p> <p>The appendices of this dissertation presents some additional data that could also be useful for researchers. A more detailed description of the methods necessary to support the VAP process, additional viscosity measurements and micro-CT images of propellant, the combustion of Al/PVDF filament in windowed propellant at pressure, and microexplosions of propellant with an Al/Zr additive are all provided in this section. </p>