论文部分内容阅读
在偶氮二异丁腈(2,2′–azobisisobutyronitrile,AIBN)引发下,研究液态超支化聚碳硅烷(hyperbranched polycarbosilane,HBPCS)的无氧热交联,考察交联温度、AIBN用量以及时间对交联反应及陶瓷产率的影响。结果表明:较高的温度可促进交联;AIBN用量越多越有利于交联,陶瓷产率先增加而后稳定,其最佳用量为1.0%～2.0%(质量分数,下同);随着交联时间延长,HBPCS的交联程度和陶瓷产率先增加而后保持不变。对于AIBN用量1.5%的体系,HBPCS经80℃交联6h后,其1000℃下的陶瓷产率高达75%以上。此外,对最终陶瓷相组成进行表征,发现AIBN的引入能够有效抑制β-SiC的结晶。
Under anaerobic conditions of 2,2’-azobisisobutyronitrile (AIBN), the anaerobic thermo-crosslinking of liquid hyperbranched polycarbosilane (HBPCS) was investigated. The effects of crosslinking temperature, AIBN dosage and time on Crosslinking reaction and ceramic yield. The results showed that the higher temperature could promote the cross-linking. The more the amount of AIBN, the more conducive to cross-linking. The ceramic yield first increased and then stabilized. The optimal dosage of AIBN was 1.0% ~ 2.0% (mass fraction) With the extension of time, the degree of cross-linking of HBPCS and ceramic yield first increased and then remained unchanged. For a 1.5% AIBN system, HBPCS produced more than 75% ceramic at 1000 ℃ after being crosslinked at 80 ℃ for 6h. In addition, the final ceramic phase composition was characterized and found that the introduction of AIBN can effectively inhibit the β-SiC crystallization.