4,4-(9-芴)二苯酚型聚碳酸酯的合成及其耐高温性能研究

Studies on Synthesis and Thermal Properties of Polycarbonate Derived from 9,9-Bis(4-hydroxyphenyl) Fluorene

以4,4-(9-芴)二苯酚(BHPF)和碳酸二苯酯(DPC)为原料,采用熔融酯交换法合成了4,4-(9-芴)二苯酚型聚碳酸酯(BHPF-PC).红外光谱、核磁共振碳谱及氢谱测试结果证实了所得聚合物的化学结构.采用了四苯基膦苯酚盐(C_(30)H_(25)OP)等2种季磷盐以及3种碱性无机盐催化剂作为合成聚碳酸酯的催化剂,结果四苯基膦苯酚盐的催化效果最好.分析了DPC/BHPF初始摩尔比对BHPF-PC的影响规律,随着DPC/BHPF初始摩尔比的增加,BHPF-PC的分子量呈现先增加后降低的趋势.进一步研究了聚合工艺包括缩聚时间和缩聚温度对BHPF-PC的影响,结果表明BHPF-PC分子量达到最大值所需要的时间随DPC/BHPF初始摩尔比的增加而增加.初始摩尔比为1.1∶1的DPC和BHPF,在1×10^(-5)mol/mol(BHPF)的四苯基膦苯酚盐催化作用下,于330℃缩聚150 min可以获得分子量最大的BHPF-PC.最后研究了BHPF-PC的耐高温性能和光学性能,其Tg达到了275℃,空气中失重率为5%时的分解温度T5%为440℃,同时透光率达到了88.1%,表明BHPFPC是一种具有优异耐高温性能的高光学透明材料.

Bisphenol-fluorene polycarbonate （BHPF-PC） was synthesized by melt transesterification of 9,9- bis（4-hydroxyphenyl） fluorene （BHPF） and disphenyl carbonate （DPC）. The chemical structure of the polymer was confirmed by a combination of FTIR,1H-NMR and 13C-NMR spectra tests. The influences of catalyst species and contents,the initial DPC/BHPF molar ratios, polymerization time and temperature on the ehemophysical properties of BHPF-PC were investigated. Two kinds of quaternary phosphonium salts including tetraphenylphosphonium phenolate （C30H25OP） and three kinds of inorganic salts were used as catalysts for the polymerization preparation of BHPF-PC, among which C30 H25 OP showed the highest catalytic activity. The impact of the initial DPC/BHPF molar ratios on the molecular weight of BHPF-PC was analyzed based on GPC measurements,and it was found that the molecular weight increased sharply when DPC was used in slight excess and then decreased with further increase of DPC/BHPF molar ratio. Furthermore,the effect of preparing conditions,such as polymerization time and temperature on the molecular weight variation of BHPF-PC was evaluated. The result indicated that the reaction time for obtaining maximum molecular weight increases with increasing initial molar ratio of DPC to BHPF. The BHPF-PC prepared by the condensation of DPC and BHPF with molar ratio of 1.1：1 in the presence of 1 × 10-5mol/mol of C30H25OP,a residence time of 150 minutes at 330℃ ,showed a desirably high molecular weight. Finally, the thermal and optical properties of BHPF-PC were evaluated. BHPF-PC has a glass transition temperature of 275℃, an initial decomposition temperature of 440℃（ T5% ） , and a light transmittance of 88.1% , indicating that BHPF-PC is an optical transparent material having excellent resistance to high temperature.