Jin Chen, Yang Hao, Zhang Yang, Zhang Shuting, Long Xu, Dong Hong, Song Yanjiang, Qu Zhirong, Wu Chuan
College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, China.
Polymers (Basel). 2024 Oct 7;16(19):2835. doi: 10.3390/polym16192835.
Linear chlorinated phosphazene acid is prepared using PCl and NHCl as raw materials. Using hexaethylcyclotrisiloxane as the monomer, 1,1,3,3-tetramethyldisiloxane or 1,3-divinyl-1,1,3,3-tetramethyldisiloxane as the end-capping agent, and linear chlorinated phosphazene acid as the catalyst, polydiethylsiloxane oligomers terminated with active Si-H or Si-CH=CH groups have been prepared. Using hexaethylcyclotrisiloxane and 1,3,5,7-octamethylcyclotetrasiloxane as comonomers, 1,1,3,3-tetramethyldisiloxane or hexamethyldisiloxane as the end-capping agent, or using hexaethylcyclotrisiloxane and octamethylcyclotetrasiloxane as comonomers, 1,1,3,3-tetramethyldisiloxane as the end-capping agent, copolymers containing active Si-H bonds and dimethylsiloxane segments have been prepared under the catalysis of linear chlorinated phosphazene acid. The effects of catalyst dosage, reaction temperature, reaction time, end-capping agent, and polymerization monomer dosage on polymer yield and structure were investigated. Using 300 ppm of linear chlorinated phosphazene acid, oligomers and copolymers containing an active Si-H bond and diethylsiloxane segment were prepared under mild conditions. The molecular weight of the obtained polymers was close to their designed values, but their PDI values were small. The highest yield of , -bisdimethylsiloxyl-terminated PDES oligomers reached 93%. Using oligomers and copolymers containing Si-H bonds and diethylsiloxane segments as crosslinkers, a silicone gel containing diethylsiloxane segments was prepared by hydrosilylation reaction. With the introduction of a diethylsiloxane segment, the glass transition temperature of the silicone gel decreased relative to that of the PDMS oligomer, but the temperature at 5% weight loss in nitrogen atmosphere decreased from 347 °C to 312 °C. The mechanism of the ring-opening polymerization of hexaethylcyclotrisiloxane catalyzed by linear chlorinated phosphazene acid is also discussed.
以PCl和NHCl为原料制备线性氯化磷腈酸。以六乙基环三硅氧烷为单体，1,1,3,3-四甲基二硅氧烷或1,3-二乙烯基-1,1,3,3-四甲基二硅氧烷为封端剂，线性氯化磷腈酸为催化剂，制备了以活性Si-H或Si-CH=CH基团封端的聚二乙硅氧烷低聚物。以六乙基环三硅氧烷和1,3,5,7-八甲基环四硅氧烷为共聚单体，1,1,3,3-四甲基二硅氧烷或六甲基二硅氧烷为封端剂，或以六乙基环三硅氧烷和八甲基环四硅氧烷为共聚单体，1,1,3,3-四甲基二硅氧烷为封端剂，在线性氯化磷腈酸催化下制备了含活性Si-H键和二甲基硅氧烷链段的共聚物。研究了催化剂用量、反应温度、反应时间、封端剂和聚合单体用量对聚合物产率和结构的影响。使用300 ppm的线性氯化磷腈酸，在温和条件下制备了含活性Si-H键和二乙硅氧烷链段的低聚物和共聚物。所得聚合物的分子量接近其设计值，但其PDI值较小。以含Si-H键和二乙硅氧烷链段的低聚物和共聚物为交联剂，通过硅氢加成反应制备了含二乙硅氧烷链段的硅凝胶。随着二乙硅氧烷链段的引入，硅凝胶的玻璃化转变温度相对于聚二甲基硅氧烷低聚物有所降低，但在氮气气氛中5%失重温度从347℃降至312℃。还讨论了线性氯化磷腈酸催化六乙基环三硅氧烷开环聚合的机理。
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