以同向紧啮合双螺杆挤出机为反应器,硅醇钠/乙酸乙酯（EA）为引发体系,通过三氟丙基甲基环三硅氧烷（F3）阴离子本体开环聚合,制备了聚三氟丙基甲基硅氧烷（PMTFPS）。采用红外光谱（FT-IR）,核磁共振（1H-NMR）和凝胶渗透色谱（GPC）确认了聚合物的结构与分子量,用电离飞行时间质谱分析了副产物的组成。研究表明,提高反应温度和EA用量可使反应平衡点提前到达。而螺杆转速对反应的主要影响在于改变聚合反应时间。因此,控制适当反应条件,使反应在平衡点到来时间之前终止,可得到高分子量以及高收率的PMTFPS。所得产物的数均分子量为2.41×105,分子量分散指数为1.12,产率为90.5%。
Poly[methyl（3,3,3-trifluoropropyl）] siloxane（PMTFPS） was polymerized by the anionic bulk ring-opening reaction of 1,3,5-tris（trifluoropropylmethyl） cyclotrisiloxane（F3） in a closely intermeshing twin-screw extruder using sodium silanolate/ethyl acetate（EA） as initiator system.The structure and number average molecular weight（M-n）of PMTFPS were confirmed by the analysis of FT-IR,1H-NMR and GPC.The constitution of side-products was analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.Finding that the increase of the reaction temperature and the dosage of EA can shorten the time for the reaction balance point to come.On the other hand,the rotation speed of screws mainly affects the polymerization retention time.Thus,to obtain PMTFPS with high M-n and yield,the polymerization is terminated before the occurrence of reaction balance point by adjusting suitable reaction conditions.In this work,PMTFPS with 2.41×105 of M-n,1.12 of distribution index and 90.5% of yield was achieved.
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