9,9-二[4-(4-胺基苯氧基)]苯基呫吨共缩聚改性聚对苯二甲酰对苯二胺

以9,9-二4-(4-胺基苯氧基)苯基]呫吨(BAPX)为第3单体,将其与对苯二甲酰氯、对苯二胺(PPD)在N-甲基-2-吡咯烷酮(NMP)中进行低温溶液共缩聚反应,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、反应初始温度、第3单体用量对共聚反应的影响,并用IR、DSC、TGA等方法对共聚物进行了表征.结果表明:新型聚芳酰胺的特性粘度为1.85～3.20 dL·g^-1,具有较高的玻璃化温度(305.6～325.7 ℃),在氮气氛中5%热失重温度为 524～544 ℃,800 ℃时的残炭率在52%以上.随着单体BAPX和PPD摩尔比的增加,共聚物的玻璃化温度逐渐降低,当BAPX和PPD摩尔比大于50/50时,共聚酰胺在常温下可溶于NMP、N,N-二甲基乙酰胺等极性有机溶剂中.

Copolymerization Modification of Poly(p-Phenylene-Terephthalaminde)with 9,9-Bis[4-(4-Aminophenoxy)phenyl]xanthene

A series of aromatic copolyamides was synthesized by low temperature solution polycondensation of 9,9-bis
4-(4-aminophenoxy)phenyl]xanthene(BAPX),terephthaloyl chloride and p-phenylenediamine(PPD)in N-methyl-2-pyrrolidinone.The effects of the molar concentration of monomer,reaction temperature and the molar ratio of BAPX to PPD on the copolycondensation reaction were investigated.The resulting copolyamides were characterized by IR,DSC and TGA,etc.The obtained copolyamides had high molecular weight with the inherent viscosity of 1.85-3.20 dL·g^-1,glass transition temperature(T_g)in the range of 305.6-325.7 ℃ and weight loss temperature(5%)in the range of 524～544 ℃,and char yield over 52% at 800 ℃ under nitrogen.It has been found the T_g decreases with the increase in molar ratio of BAPX to PPD.When the molar ratio of BAPX to PPD is greater than 50/50,these polymers were readily soluble in polar solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidinone at room temperature.