| 摘要 |
Superpolyamides are made from m-xylylene diamine and aliphatic dicarboxylic acids having 6-10 carbon atoms. The polymers from a ,o -polymethylene acids having 6, 8 or 10 carbon atoms are crystalline and fibre-forming while the polymers from acids having 7 or 9 carbon atoms are amorphous and useful for films. The polyamides in general have melting points above 170 DEG C. and correspondingly high heat distortion points. The polyamides are obtained by first forming the salt and either separating the salt from aqueous solution prior to polymerization or heating the aqueous solution to remove water and form a low polymer, followed by further polymerization of the low polymer. In examples, polyamides are prepared from m-xylylene diamine and (1) and (2) adipic acid; (3) sebacic acid; (4) azelaic acid; (5) pimelic acid. |
