摘要
以γ-巯丙基三乙氧基硅烷、二苯基二甲氧基硅烷及六甲基二硅氧烷为原料,浓盐酸为催化剂,采用水解缩聚法,制得高折射率巯基MDT(S-MDT)硅树脂。将S-MDT硅树脂、苯基乙烯基硅油和2-羟基-2-甲基苯基丙酮于暗处搅拌均匀,经紫外光固化制得固化物。研究了催化剂用量、水解温度及时间、缩聚温度及时间、苯基质量分数对S-MDT硅树脂性能的影响,并采用红外光谱、核磁共振波谱、凝胶渗透色谱分析了产物结构与摩尔质量分布,还研究了S-MDT硅树脂的固化动力学及其固化物的力学性能、热稳定性和透光率。结果表明,较佳合成工艺为:催化剂用量2.00%、水解温度80℃、水解时间3 h、缩聚温度120℃、缩聚时间3 h、苯基质量分数16.23%、有机取代基与硅原子的量之比1.88。此条件下,S-MDT硅树脂为透明黏稠物,黏度为3890 m Pa·s、摩尔质量分布系数为1.11、折射率为1.5685。此外,当S-MDT硅树脂中巯基与苯基乙烯基硅油中乙烯基的量之比为2/1时,体系双键转化率为93%,固化物的拉伸强度为2.96 MPa、拉断伸长率为160%、交联密度为2.06×10^-3mol/cm^3、最大热分解速率温度为448.54℃、可见光透光率高于91%。
The thiol-based MDT(S-MDT)silicone resins with high refractive index have been synthesized based on hydrolysis polycondensation by usingγ-(methacryloyloxy)propyltrimethoxysilane,diphenyldimethoxysilane and hexamethyldisiloxane with hydrochloric acid(HCl)as catalyst.The prepared S-MDT silicone resin,phenyl vinyl silicone oil and 2-hydroxy-2-methyl propiophenone were mixed and stirred evenly in the dark,then cured under UV light.The properties of S-MDT silicone resins were studied by catalyst content,temperature and time of hydrolysis and polycondensation,and the mass fraction of phenyl.The structures and molecular weight distribution of the photo-curing products were analyzed by Fourier transform infrared spectroscopy,nuclear magnetic resonance spectroscopy and gel permeation chromatography.The curing kinetics of S-MDT silicone resin and the mechanical properties,thermal stability and transmittance of the cured product were also studied.Results show that the preferred synthesis process is hydrochloric acid of2.00 wt%,hydrolysis temperature of 80℃,hydrolysis time of 3 h,condensation temperature of 120℃,polycondensation time of 3 h,phenyl content of 16.23 wt%and R/Si value of 1.88.Under these conditions,S-MDT silicone resin is a transparent viscous substance with a viscosity of 3890 m Pa·s,a molecular weight distribution index of 1.11,and a refractive index of 1.5685.In addition,when the molar ratio of the mercapto group in the S-MDT silicone resin to the vinyl group in the phenyl vinyl silicone oil is 2/1,the liquid silicone resin has the double bond conversion rate of 93%.For the cured product,the tensile strength is 2.96 MPa,the elongation at break is 160%,the crosslink density is 2.06×10^-3 mol/cm^3,the maximum temperature of thermal decomposition rate is 448.54℃,and the visible light transmittance is higher than 91%.
作者
刘珠
杨先君
向洪平
洪鹏
黄梓英
李伟健
林浩源
罗青宏
刘晓暄
LIU Zhu;YANG Xian-jun;XIANG Hong-ping;HONG Peng;HUANG Zi-ying;LI Wei-jian;LIN Hao-yuan;LUO Qing-hong;LIU Xiao-xuan(Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter,School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,Guangdong)
出处
《有机硅材料》
CAS
2020年第3期1-12,共12页
Silicone Material
基金
国家自然科学基金(51873043,21604014)
大学生创新创业计划项目(gj201811845029,xj201911845359)。
关键词
液态MDT硅树脂
水解缩聚法
紫外光固化
高折射率
高可见光透光率
liquid MDT silicone resin
hydrolysis polycondensation
UV-curing
high refractive index
high visible light transmittance
