碳硼烷酚醛树脂的合成及性能研究

Synthesis and Properties of m-Carborane-Based Bisphenol-Type Phenolic resin

以m-碳硼烷为原料,通过Ullmann反应和脱甲基反应获得1,7-二(4-羟基苯基)-m-碳硼烷(1),进一步得到热固性的碳硼烷酚醛树脂(preP1),研究了反应温度、反应时间、摩尔比、催化剂种类和用量对碳硼烷酚醛树脂合成的影响。通过1H-NMR、FTIR等标准方法表征了单体和树脂的结构,并研究了固化物的热失重性能和高温结构转变行为。结果表明,催化剂为NaOH、控制和条件为100℃/8h时,得到数均分子量(M n)为1035的preP1,HRMS分析表明其主要成分为羟甲基化碳硼烷双酚A。preP1固化产物在氮气和空气气氛下900℃时的残炭率分别为88.9%和92.9%,远高于市售硼酚醛固化物。空气中preP1在685℃时B—H键与氧气反应生成含B—O—B键的三维网状结构,因此固化物发生明显增重。

Abstract 1,7-Bis （4-hydroxyphenyl）-m-carborane （preP1） was synthesized from m-carborane by Ullmann reaction, demethylation, and reaction with formaldehyde . The effects of catalyst species, phenol/formaldehyde molar ratio, temperature and time on synthetic reactions were carefully studied. The obtained preP1 was characterized with FTIR,1H NMR,13C NMR and MS methods. TGA behavior and structure transformation of cured preP1 was also investigated. The results show that preP1 （Mn = 1035） with hydroxymethylcarboranebisphenolA as main component was obtained when NaOH is used as catalyst under the condition of 100℃/8h. The char of cured preP1 at 900℃ in nitrogen and air is 88.9% and 92.9% , which are much higher than that of commercially obtained boron-containing phenolic resin. It is believed that under air B-H bonds in preP1 could react with oxygen and transform to three-dimensional network structure containing B-O-B bonds. Therefore, the cured products gain weight at 685℃.