聚酰亚胺／聚N－乙烯吡咯烷酮分子复合物的合成和表征

由原位缩聚制备了刚性高分子聚酰亚胺（ＰＩ）和柔性基体聚Ｎ－乙烯吡咯烷附（ＰＶＰ）的分子复合物，并由实验证明了中间体聚酰胺酸（ＰＡ）和聚乙烯吡咯烷酮大分子之间存在的酸一碱相互作用．这种相互作用促进了混容性，使聚酰亚胺能以分子水平或接近分子水平分散在聚毗咯烷酮的基体之中．聚酰亚胺／聚Ｎ－乙烯吡咯烷团分子复合物的薄膜呈透明性，在整个组成范围内只有一个Ｔｇ，显示单相行为。当ＰＩ含量＜２０％时，ＳＥＭ相片呈现均相形貌，看不到ＰＩ微晶．广角Ｘ－ｒａｙ衍射图表明ＰＩ特征结晶峰消失，和无定形的ＰＶＰ完全混容．当ＰＩ含量＞４０％，ＳＥＭ显示有均匀分布的、棒状ＰＩ微晶存在．通过分子复合，即使ＰＩ含量为１０％，聚Ｎ－乙烯吡咯烷酮不再溶于乙醇，耐热性也有提高．

SYNTHESIS AND CHARACTERIZATION OF MOLECULAR COMPOSITES OF POLYIMIDE /POLYVINYLPYRROLIDONE

he molecular composites of a rigid polymer polyindde (PI) with a flexible matrix polymer polyvinylpyrrolidone (PVP) were successfully synthesized by in-situ polycondensation. A strong specific interaction of acid-base between the polyamic acid (the precursor of PI) and the PVP was confirmed experimentally. By this specific interaction the ndscibility of PI with PVP was substantially improved.The PI dispersed in the PVP matrix polymer on a molecular level or nearly molecular level.The films of the molecular composites of PI /PVP are transparent' Only one Tgexhibited over the whole composition range suggesting a homogeneous phase. No phase separation was observed by SEM for the sample with PI content <20%. Thewide angle X-ray diffraction patterns showed the disappearance of the crystallization peaks of PI. In this case the PI was totally miscible with theamorphous PVP. However when PI content was >40% the finely dispersed rod-likePI micro-crystals can be found by SEM. Due to the molecular composite formationo f PVP with PI, the PVP become insoluble in ethanol even with only 10% PI.