POLYMER BULLETIN
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2021
·Vol. 79
·期 9
·7177-7192
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IF 2.87
Pan Zhaoqun,Chen Mianfeng,Zeng Keling,Kang Yingzi
In this paper, a cyclotetrasiloxane modified with epoxy resin was synthesized via hydrosilylation with 1, 3, 5, 7-tetramethylcyclotetrasiloxane (D4H) and 4-vinyl-1-cyclohexane 1, 2-epoxide (VCHO). The structure of tetramethylcyclotetrasiloxane modified with cyclohexane epoxide (D4H–VCHO) was characterized by Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC). The effects of feeding methods, feeding ratios, catalyst dosages, reaction temperature and reaction time on the products were investigated. After 4-h reaction with 8 ppm catalyst at 90 °C, D4H–VCHO was obtained with an epoxy value of 0.521 and a refractive index of 1.4920. Then, with 4-methylhexahydrophthalic anhydride as a curing agent and tetrabutylammonium bromide as a catalyst, the obtained D4H–VCHO was cured at 90 °C for 1 h and then 120 °C for another hour. The cured products showed high light transmittance, strong thermal stability, suitable hardness and low water absorption. The glass transition temperature of cured materials was 151.6 °C, indicating the improvement of flexibility. In addition, the introduction of epoxy groups greatly enhanced the adhesion of silicone resins to substrates. The results demonstrated that the epoxy-modified silicone materials could be applied as LED packaging materials.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2015
·Vol. 132
·期 27
·
IF 1.768
Yan Zhang,Yin-wen Li,Jian Zheng,Hui-long Guo,Xiao-xiao Guan,Man-geng Lu,Kun Wu,Li-yan Liang
A novel thermal stability and highly transparent silicone resin-type material was prepared via hydrosilylation of vinyl-polyhedral oligomeric silsesquioxanes (POSS)-grafted methylhydrosilicone oil and vinylmethylsilicone oil in the presence of Karstedt catalyst. The morphology, mechanical property, thermal stability, optical transmittance, thermal-oxidation resistance of the vinyl-POSS-reinforced silicone resins were systematically investigated. Scanning electron microscopy showed that the vinyl-POSS-reinforced silicone resins had good compatibility with polydimethylsiloxane (PDMS) systems. The mechanical analysis and thermo gravimetric analysis indicated that the mechanical properties and thermal stability increased with increasing quantity of vinyl-POSS. However, the optical transmittance increased with the increasing amount of vinyl-POSS rather than decreased. In addition, the incorporation of vinyl-POSS did not improve the thermal resistance of the PDMS polymers. The product has the potential application for LED packaging. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42187.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
Materials
·
2017
·Vol. 10
·期 2
·149
·
IF 2.654
Liang Wang,Da-Gang Guo
A UV-curable poly(butyl fumarate) (PBF)/poly(propylene fumarate)-diacrylate (PPF-DA) hybrid material with good performance for LED encapsulation is introduced in the paper. They have been prepared by radical polymerization using PBF and PPF-DA macromers with a UV curing system. PBF and PPF-DA were characterized by Fourier-transform infrared (FT-IR) and H-nuclear magnetic resonance (1H NMR). The thermal behavior, optical and mechanical properties of the material were examined by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), ultraviolet-visible spectroscopy (UV–vis), and a material testing system mechanical testing machine, respectively. The results indicated that the hybrid material has a suitable refractive index (n= 1.537) and high transmittance (99.64% in visible range) before/after thermal aging. With the increasing of the double bond ratio from 0.5 to 2, the water absorption ratios of the prepared encapsulation material were 1.22%, 1.87% and 2.88%, respectively. The mechanical property experiments showed that bonding strength was in the range of 1.86–3.40 MPa, tensile-shear strength ranged from 0.84 MPa to 1.57 MPa, and compression strength was in the range of 5.10–27.65 MPa. The cured PBF/PPF-DA hybrid material can be used as a light-emitting diode (LED) encapsulant, owing to its suitable refractive index, high transparency, excellent thermal stability, lower water absorption, and good mechanical properties.Keywords:poly(butyl fumarate)-based polymer;composites;characterization;UV-curing;LED encapsulant
研究领域:
材料科学
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高分子化学
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光电子学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
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2020
·Vol. 38
·期 9
·973-982
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IF 3.154
Zhao Dong,Shan Shu-Xi,Zhang Meng,Zhang Xiao-A,Jiang Sheng-Ling,Lyu Ya-Fei
Vinyl-containing titanium-silphenylene-siloxane oligomers ( O1 , O2 , O3 , and O4 ) with different molar ratios of titanium to silicon were successfully synthesized in high yields by nonhydrolytic sol-gel reaction, and the obtained four oligomers were further crosslinked with methylphenyl hydro-silicone oil ( 4 ) to form corresponding polymers ( P1 , P2 , P3 , and P4 ) by hydrosilylation reaction. Their structures were characterized with spectroscopic characterization techniques including FTIR, 1 H-NMR, and Raman spectroscopy. The effect of titanium element on crosslinking behavior, thermal resistance, refractive index, transparency, thermal aging stability, glass transition temperature, and surface properties of the polymers were studied. Compared with titanium-free polymer P1 , the thermal resistance, refractive index, and thermal aging stability of titanium-silphenylene-siloxane polymers ( P2 , P3 , and P4 ) were significantly improved. The titanium-silphenylene-siloxane polymers achieved a high refractive index ( n = 1.580–1.584) and thermostability ( T 5d > 500 °C). In thermal aging, the polymers exhibited superior performances with high optical transparency (~90% at 450 nm) and exhibited high thermal stability (~84% at 450 nm after thermal aging at 150 °C for 120 h). These data indicate that the polymers have potential application in optical materials such as LED encapsulants.
研究领域:
材料科学
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聚合物化学
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光学材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）