新型苯并噁唑侧基聚酰亚胺的合成、结构与性能研究

Synthesis,Structure and Properties of the Novel Polyimide with Benzoxazoline Pendent Group

为了改善聚酰亚胺的不溶不熔性,一类可溶性苯并噁唑侧基聚酰亚胺树脂被成功制备.从合成的新型二元胺单体出发,制备了侧链为邻羟基苯胺酰胺结构的聚酰亚胺体系,进一步催化环化邻羟基苯胺酰胺为苯并噁唑结构,并对这两类不同结构的聚合物树脂进行了红外光谱的结构表征,以及最终成膜的力学性能和耐热性能测试.研究结果表明:苯并噁唑侧基聚酰亚胺的力学性能优于相应的主链型聚酰亚胺,且TGA分析表明,其初始分解温度高达597℃,有望用于航空航天方面高强、高模、耐高温的结构材料.

A novel diamine monomer 3,5-diaminobenzoic-4＇-（o-hydroxy） aniline acylamide has been synthesized, and a new polyimide （PI） containing pendent benzoxazoline group was synthesized from this diamine, 3,3＇,4,4＇-oxydiphthalic dianhydride （ODPA） and bis（4-aminophenyl）ether （ODA） by a one-step high- temperature polycondensation with a certain catalyzer in 1-methyl-2-pyrrolidinone （NMP）. This PI is soluble in NMP. At the same time, mechanical and thermally stable properties of the PI film were investigated. The excellent mechanical properties of general polyimide films are reasonably maintained, and the polyimide film with pendent groups showes higher tensile strength （158 MPa） and modulus （2.4 GPa）. TGA study showes a typical two-step weight loss behavior corresponding to the pyrolysis of pendent groups and main chains of the PI with （o-hydroxy）-anilide, respectively. Moreover, the PI with benzoxazoline side groups has one-step weight loss behavior, and an initial decomposition temperature near 597 ℃ was obtained.