Novel reagents, bis(1-methoxy-2-methyl-1-propenyloxy) silanes () have been shown to be very useful bifunctional protecting agents for various types of H-acidic materials, such as diols, dithiols, diacids and their combined materials. The reaction proceeds rapidly under mild conditions to give the corresponding silylene derivatives in almost quantitative yields.
The concomitant cationic polymerization of an epoxy resin and a hybrid monomer is a new concept for toughening epoxy resins. Thermolatent super acids are superior initiators of twin monomer polymerization and copolymerization. Determination of gel yield and instrumental characterization of the formed complex polymer network indicate that copolymerization occurs, integrating the linear silicone and novolak formed during twin polymerization into the epoxy network. (C) 2013 Elsevier Ltd. All rights reserved.
4H-1,3,2-Benzodioxasilines represent a class of monomers, which are suitable for the recently developed concept of twin polymerization. Relating to the prediction of quantum chemical calculations we are now able to confirm the results for the first step of the reaction: the selective ring opening of 4H-1,3,2-benzodioxasilines. An electrophilic attack of iodotrimethylsilane leads firstly to a bond cleavage at the oxymethylene group and not at the more stable Si–O–aryl bond, yielding ring-opened species.
Thermally Induced Twin Polymerization of 4<i>H</i>-1,3,2-Benzodioxasilines
作者:Patrick Kempe、Tina Löschner、Alexander A. Auer、Andreas Seifert、Gerhard Cox、Stefan Spange
DOI:10.1002/chem.201400038
日期:2014.6.23
The twin monomer 2,2′‐spirobi[4H‐1,3,2‐benzodioxasiline] (1) can be polymerized to nanostructured SiO2/phenolic‐resin composite material by thermallyinducedtwinpolymerization. Thermallyinducedtwinpolymerization represents a way to produce nanocomposites simply by thermal induction of twin monomers. Besides 1, the thermal reaction of several related salicylic (2‐oxybenzylic) silicon molecules
双单体2,2'-spirobi [4 H -1,3,2-苯并二恶唑啉](1)可以通过热诱导双聚合反应聚合成纳米结构的SiO 2 /酚醛树脂复合材料。热诱导的孪生聚合代表了一种简单地通过孪生单体的热诱导来生产纳米复合材料的方法。除1外,还研究了几种相关的水杨酸(2-氧苄基)硅分子的热反应。通过使用几种捕获试剂(例如,乙烯基化合物)研究了分子的热裂解。醌甲基化物加合物的大量出现表明,热机理不仅通过在甲醛位置的开环进行,而且通过邻位进行。甲基苯醌作为中心中间体或替代中间体。对1及其取代的类似物进行热初始化反应的产物分析以及量子化学计算都支持这一点。