摘要
合成了一种含氰基联苯氧基侧链的二元胺单体,然后通过两步法热酰亚胺化工艺制备了新型的含氰基联苯基团侧链的聚酰亚胺。通过侧链的引入,聚酰亚胺的溶解性获得了很大的提高,同时聚酰亚胺的Tg也大大降低,从而大大改善了聚酰亚胺的溶液与熔融加工性能。在加工性改善的同时,这种侧链聚酰亚胺仍然保持了原有无侧链聚酰亚胺的优异力学性能。X射线衍射结果表明,没有侧链且较为刚性的BPDA/MPDA的聚酰亚胺表现出一种短程有序结构,但这种短程有序受到氰基联苯侧链的明显抑制。TGA研究表明侧链聚酰亚胺表现出典型的两段式失重行为,分别对应于侧链与主链的热分解。
A novel diamine with pendent cyano-biphenyl group was newly synthesized. Based on this monomer, several novel polyimides bearing side chains composed of cyano-biphenyl mesogenic end groups and hexylene spacer were prepared. By incorporating side chains, the solubility of resulted polyimide was greatly enhanced; meanwhile the excellent mechanical properties of general polyimides films were reasonably maintained, the polyimide with side chains showed high tensile strength and modulus. X-ray diffraction revealed ODPA based polyimides with biphenyl side chains only showed one amorphous halo centered around (22°), while for the more rigid BTDA based polyimides, short-range ordering in some extent were observed, this ordering structure was reduced by the introduction of cyano biphenyl group. TGA studies showed typical two-step weight loss behaviors corresponding to the pyrolysis of side chains and main chains respectively.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2004年第5期101-104,共4页
Polymer Materials Science & Engineering
基金
国家自然科学基金(20274026)
国家八六三(2001AA334020)资助项目
