Abstract To investigate the optimal reaction conditions for the preparation of methoxy functionalized MQ silicone resin( MMQ),The MMQ was synthesized through the hydrosilylation reaction of Methyl-vinyl containing MQ silicone resin( MVMQ) and trimethoxy( TMOS) siloxane using H2PtCl6 as a catalyst. The conversion of vinyl groups in MVMQ was determined by means of measuring the mass fraction of unreacted vinyl groups using iodometric method. Then,the effects of reaction temperature,reaction time,catalyst dosage,and molar ratio of Si—H/Si—CH=CH2 on conversion ratio of vinyl groups were investigated. By fourier transform infrared spectrum( FT-IR) and nuclear magnetic resonance(~1H-NMR),the structure of the products were characterized. It showed that the MMQ was synthesized successfully and the optimal reaction conditions were reaction time of 6 h,reaction temperature of 80 ℃,catalyst dosage of 10 μg/g( relative to quality of MVMQ),and molar ratio of Si—H/Si—CH=CH2 of 1. 3∶ 1. The conversion rate of vinyl groups in MVMQ was 78. 58%.
|
Received: 18 September 2020
|
|
|
|