Fabrication of Particles and Crystals of Poly(p-phenylene pyromelliteimide) and the Study on Crystal Structure
Fabrication of Particles and Crystals of Poly(p-phenylene pyromelliteimide) and the Study on Crystal Structure
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DOI：
10.1021/ma062032y
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发表时间：
2007
期刊：
影响因子：
5.5
通讯作者：
Kanji Wakabayashi;T. Uchida;S. Yamazaki;K. Kimura;K. Shimamura
中科院分区：
文献类型：
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作者：
Kanji Wakabayashi;T. Uchida;S. Yamazaki;K. Kimura;K. Shimamura
用相分离法研究了均苯四甲酸二酐(PMDA)与对苯二胺(PPDA)聚合过程中聚对苯二甲酸亚胺(PPPI)的形态结构。聚合反应在330℃下进行6h，待PMDA完全溶解后，在芳香族溶剂中加入不同温度的PPDA。随着PPDA加入量(Tad)的升高，析出物的形态发生了很大变化。当TAD为240C时，通过液态−液相分离形成液滴，形成细小颗粒。相反，当Tad高于280°C时，齐聚物结晶形成菱形晶体和针状晶体星状聚集体的混合物。TAD影响齐聚物的亚胺化程度，导致PPPI形态发生变化。用高分辨透射仪研究了菱形晶体的晶体结构和分子链取向.
Morphologies of poly(p-phenylene pyromelliteimide) (PPPI) were investigated by using phase separation during polymerization of pyromellitic dianhydride (PMDA) and p-phenylene diamine (PPDA). Polymerizations were carried out at 330 °C for 6 h. PPDA was added to the solution of PMDA in an aromatic solvent at various temperatures after PMDA was entirely dissolved. The morphology of the precipitates was drastically changed with the temperature of PPDA addition (Tad). When Tad was 240 °C, the fine particles were formed through the formation of droplets via liquid−liquid phase separation. On the contrary, when Tad was higher than 280 °C, the mixture of lozenge-shaped crystals and starlike aggregates of needlelike crystals were formed by the crystallization of oligomers. Tad influenced the degree of imidization of oligomers, resulting in the variation in the morphology of PPPI. Crystal structure and molecular chain orientation of the lozenge-shaped crystals were also investigated by high-resolution transmission ...