9,9-二[4-(4-羧基苯氧基)]苯基呫吨/对苯二胺/对苯二甲酸共聚酰胺的研究

采用Yamazaki聚合体系,以9,9-二4-(4-羧基苯氧基)苯基]呫吨(BCPX)为第三单体,将其与对苯二甲酸(PTA)、对苯二胺(PPD)进行共缩聚反应,合成了一系列含呫吨结构的聚酰胺共聚物.研究了单体摩尔浓度、反应温度、BCPX和PTA摩尔比等对共聚反应的影响,并用IR、DSC、TGA等方法对共聚物进行了表征.结果表明,新型聚芳酰胺的对数比浓粘度为1.90～2.95 dL?g^-1,具有较高的玻璃化温度(T_g=297.3～320.5 ℃),在氮气氛中5%热失重温度为522～540 ℃,800 ℃时的残炭率在51% 以上.随着单体BCPX和PTA摩尔比的增加,共聚物的T_g逐渐降低,当BCPX和PTA摩尔比大于50/50时,共聚酰胺在常温下可溶于N-甲基-2-吡咯烷酮、N,N-二甲基乙酰胺、吡啶等极性有机溶剂中.

The Copolyamides from 9,9-Bis[4-(4-Carboxyphenoxy)phenyl]xanthene,1,4-Diaminobenzene and 1,4-Dicarboxybenzene

New aromatic copolyamides bearing xanthene structure are prepared from 9,9-bis4-(4-carboxyphenoxy)phenyl]xanthene(BCPX),p-phenylenediamine(PPD)and terephthalic acid(TPA)using Yamazaki method via direct polycondensation.The effects of the molar concentration of monomer,reaction temperature and the molar ratio of BCPX to TPA on the copolycondensation reaction are investigated.The resulting copolyamides are characterized by IR,DSC and TGA,etc.The obtained copolyamides had high molecular weight with the inherent viscosity of 1.90～2.95 dL?g^-1,glass transition temperature(T_g)of 297.3～320.5 ℃ and 5% weight loss temperature of 522～540 ℃,and char yield over 51% at 800 °C under nitrogen.It has been found the T_g decreases with the increase in molar ratio of BCPX to TPA.When the molar ratio of BCPX to TPA is greater than 50/50,these polymers are readily soluble in polar solvents such as N-methyl-2-pyrrolidinone,N,N-dimethylacetamide and pyridine at room temperature.