过氧化苯甲酰在液态聚碳硅烷交联中的应用

Application of dibenzoyl peroxide in cross-linking of a liquid polycarbosilane

聚碳硅烷热解前的交联对于提高其最终陶瓷产率至关重要。研究了过氧化苯甲酰(BPO)引发液态超支化聚碳硅烷(HBPCS)的交联反应对于陶瓷产率的影响。FT-IR和GPC证实,添加为0.5%～2.0%(质量分数,下同)的BPO,即可在80～140℃下引发HBPCS交联;在考察的实验条件下,提高交联温度、延长反应时间或增加BPO用量,均可提高HBPCS交联程度。BPO用量为2.0%时,HBPCS交联样品在1000℃下的陶瓷产率高达65%,比未加BPO的提高25%。

In order to increase the final ceramic yield, the cross-linking of polycarbosilane prior to its pyrolysis is very important. In this paper, benzoyl peroxide (BPO) was used to initiate the cross-linking of a hyperbranched liquid polycarbosilane (HBPCS), and the influence of the cross-linking on the ceramic yield was studied. The results indicate that the cross-linking was successfully initiated at 80-140°C with the weight ratio of BPO to HBPCS of 0.5%-2.0%, which was conformed by means of Fourier transform infrared (FT-IR) and gel permeation chromatography (GPC). It was found that higher reaction temperature, longer reaction time or more BPO content improves the cross-linking reaction under the investigated reaction conditions. The ceramic yield of cross-linked HBPCS intiated by 2.0% BPO reached 65%, which is 25% higher than that of HBPCS without BPO.