紫外光固化丙烯酸酯化聚硅氧烷的合成及其弹性体性能研究

Synthesis and Property of UV-curable Acrylate Functionalized Polysiloxane

以二甲基二乙氧基硅烷(DMDESi)和γ-甲基丙烯酰氧基丙基甲基二甲氧基硅烷(USi-3311)为原料,四甲基氢氧化铵(TMAH)为催化剂,通过水解-缩聚反应合成了一种可快速紫外光固化成型为弹性体的丙烯酸酯化聚硅氧烷,并对缩聚反应条件、紫外光固化动力学及其弹性体性能进行了研究。结果表明,水解温度为60℃,水解时间为2 h,催化剂质量分数为0. 7%,缩聚温度为95℃,缩聚时间为1. 5 h,DMDESi和USi-3311的量之比为50∶1时,合成的丙烯酸酯化聚硅氧烷的黏度为2 528 m Pa·s,双键含量为12 mmol/100 g;光固化过程中双键转化率为90%,凝胶时间为4. 5 s;光固化弹性体的玻璃化温度为-126℃,拉伸强度和拉断伸长率分别为70 k Pa和107%。

A novel acrylicesterifiedpolysiloxane,which can berapidlycuredinto silicone elastomer,issynthesized by hydrolysis-condensation,with dimethyldiethoxysilane(DMDESi)andγ-methacryloxypropylmethyldimethoxysilane(USi-3311)as the raw materials,tetramethylammoniumhydroxide(TMAH)as the catalyst.The condensation conditions,UV curing kinetics,and the properties of the elastomers are studied.Results show that the optimum hydrolysis temperature is 60℃,hydrolysis time is 2 h,the mass fraction of catalyst is 0.7%,and the condensation temperature is 95℃,polycondensation time is 1.5 h,and the ratio of DMDESi to USi-3311 is 50∶1.The obtained polysiloxane has a viscosity of 2528 mPa·s and content of double bond of 12 mmol/100 g.During the photocuring process,the double bond conversion rate is 90%,and the gelation time is about 4.5 s.DMA demonstrates the glass transition temperature is-126℃.The tensile strength and elongation at break of silicone elastomer are 70 kPa and 107%,respectively.