摘要 |
A para-aramid fibrid film is disclosed that has at least 95% of the bonds of the polymer are para-oriented. A method for making said para-aramid fibrid film by (a) polymerizing a para-oriented aromatic diamine and a para-oriented aromatic dicarboxylic acid halide to an aramid polymer having only para-oriented bonds in a mixture of solvents consisting of N-methylpyrrolidone or dimethylacetamide and calcium chloride or lithium chloride to obtain a dope wherein the polymer is dissolved in the mixture of solvents and the polymer concentration is 2 to 6 wt. %, and (b) converting the dope to para-aramid fibrid film is also described. |