高分子量氟硅生胶催化剂的选择及应用

Selection and Application of Catalyst for High Molecular Weight Fluorosilicone Raw Rubber

在高分子量氟硅生胶合成领域,通常用碱来催化氟硅单体D3F[2,4,6-三甲基-2,4,6-三(3,3,3-三氟丙基)环三硅氧烷]阴离子开环聚合。本研究为了筛选出合适的催化体系,选用了不同碱分别与D3F反应,制备并评估了5种碱胶。其中,氢氧化钠(NaOH)和正丁基锂(nBuLi)碱胶外观均一透明,贮藏稳定性以及在D3F中的分散性较好,经反应成为有效成分(硅烷醇盐)的转化率较高,活性适中有利于控制副产物,与氢氧化锂(Li OH)、氢氧化钾(KOH)和四甲基氢氧化铵(TMAOH)相比,是更适合用于合成高分子量氟硅生胶的催化体系。

In the field of synthesis of high molecular weight fluorosilicone raw rubber,alkali is usually used to catalyze the anionic ring opening polymerization of fluorosilicone monomer D3F[2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl)cyclotrisiloxane].To screen out a suitable catalyst system,different bases were used to react with D3F,and five alkali gels were prepared and evaluated in this paper.Among them,sodium hydroxide(NaOH)and n-butyl lithium(nBuLi)alkali gel have uniform and transparent appearance,good storage stability and dispersion in D3F,high conversion rate of effective component(silanolate)through reaction,and moderate activity which is conducive to controlling by-products.Compared with lithium hydroxide(LiOH),potassium hydroxide(KOH)and tetramethylammonium hydroxide(TMAOH),they are more suitable for synthesizing high molecular weight fluorosilicone raw rubber.