Research On The Structure And The Properties Of The Low Viscosity Polyimide Resin

The main purpose of this paper is to synthesize soluble polyimides with high molecular weight, low viscosity that are suitable for Resin Transfer Molding. In this dissertation, the main works are listed as follows:1. Twelve kinds of Phenylethynyl end-capped polyimides were synthesized by using2,3,3’,4’-Tetracarboxydiphenyl oxide dianhydride,3,3,4’,4’-Tetracarboxydiphe-nyl oxide dianhydride,2,3,3’,4’-biphenyltetracarboxylic dianhydride,3,4’-oxydian-iline,4,4’-oxydianiline,m-phenylenediamine and2,2’-Bis(trifluoromethyl)benzidine.2. The results show that, all kinds of polyimides exhibit low melt viscosity and excellent solubility at high temperature.5%thermal weight loss (T5%) of all the cured resins is higher than530℃, all resins exhibit preferable thermal stability. The glass transition temperature (Tg) of the polyimides resins are high, and the highest Tg is358℃. In addition, the resin castings show good mechanical properties.3. Using NMP as solvent, the carbon fiber reinforced polyisoimide matrix composites were, the flexural strength of the carbon fiber reinforced composites is more than1Gpa, and its retention is more than50%at high temperature, exhibit excellent mechanical properties...