摘要
首先制备液晶基元,以对羟基苯甲酸甲酯和1,4-丁二醇为原料,钛酸四正丁酯为催化剂,通过熔融酯交换反应合成了液晶基元双(对羟基苯甲酸)丁二醇酯。对反应的最佳条件进行了考察得出结论:在对羟基苯甲酸甲酯为15.5 g,1,4-丁二醇为4.4 mL,钛酸四正丁酯为2.5 mL,反应温度为160℃时,反应进行的较完全,分出甲醇的量接近理论值4 mL。对所得的液晶基元的DSC及POM分析表明,该液晶基元没有液晶性。然后,将液晶基元与对苯二甲酰氯反应制得对苯二甲酰氯苯甲酸丁二醇酯(PHTO),将对苯二甲酰氯苯甲酸丁二醇酯(PHTO)与2,4-甲苯二异氰酸酯(2,4-TD I)反应制得液晶聚氨酯。用差热扫描量热分析仪(DSC)、偏光显微镜(POM)对产物的熔点和清亮点、液晶性进行表征。结果表明:合成的聚氨酯产物在202℃(熔点)和261℃(清亮点)之间为热致性向列型液晶。
The recent research and development of liquid crystalline polyurethanes were revieved, Bis （ p - hydroxybenzoic acid） butanediolate which is a kind of mesogenic unit was synthesized by melting transesterification using methyl - p - hydroxybenzoate, 1,4 -butanediol, and tetrabutyl titanate as catalyst. The best reaction conditions were studied. Consequently, the optimum conditions were determined as follows： methyl - p - hydroxybenzoate 15.5g, 1,4 - butanediol 4.4mL, tetrabutyl titanate 2.5mL, temperature 160℃. While the monomer reacted completely, the yield of methanol quantity approached 4mL which is the value of theory. The mesogenic unit was identified by means of DSC and HS - POM analysis. It was found that the production is not liquid crystalline compound. The LCPU was characterized by FTIR,DSC and POM. The observation of POM showed that the hquid crystal polyurethane was a thermotropic nematic liquid crystalline polymer at certain temperature range.
出处
《辽宁化工》
CAS
2008年第4期220-222,226,共4页
Liaoning Chemical Industry
关键词
液晶
热致性
合成
聚氨酯
Liquid
Thermotropic
Synthesis
Crystalline polyurethane
