【摘要】 以均苯四甲酸酐(PMDA)和甲苯二异氰酸酯(TDI)为原料,采用一步法缩聚反应在较低的温度下制备了PMDA-TDI聚酰亚胺。采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、差示扫描量热(DSC)、扫描电镜(SEM)、热重(TG)和耐溶剂性能分析等方法对聚酰亚胺进行表征,探讨不同TDI和PMDA的摩尔比对聚酰亚胺产品结构和性能的影响。结果表明,随着TDI和PMDA的摩尔比增大,产物中的聚脲和TDI二聚体增多,导致聚酰亚胺产品纯度降低,同时玻璃化转变温度降低,耐热性能略有下降。当TDI和PMDA摩尔比为1.1时,合成的聚酰亚胺纯度最高,耐热性能最好,同时该样品具有优异的耐溶剂性能。更多还原

【Abstract】 A kind of polyimide(PI) was synthesized via one-step polycondensation using pyromellitic dianhydride(PMDA) and toluene diisocyanate(TDI).The FTIR,XRD,DSC,SEM,TG and chemical resistant tests were conducted to characterize the effect of mole ratio of TDI to PMDA on the structure and performance.Results showed that,the polyurea and TDI-dimer in product increased with the mole ratio of TDI to PMDA,leading to the decrease in product purity,glass transition temperature and heat resistance.It is indicated that the PMDA-TDI PI synthesized with the mole ratio of TDI to PMDA of 1.1 has the optimal product purity and heat resistance,meanwhile has a good solvent resistance.更多还原