| 摘要 |
Crystalline semiaromatic copolyamides exhibiting especially a glass transition temperature Tg higher than 142 DEG C, and therefore an excellent stability of the polymer at elevated temperatures, as well as a melting temperature Tm lower than 290 DEG C. …<??>They have a structure containing the repeat units (I), (II), optionally (II') and (III): (I) denoting: …<IMAGE>… (II) denoting: …<IMAGE>… (II') denoting: …<IMAGE>… and (III) denoting: …<IMAGE>… with R1, R2, R3 and R4 denoting alkyl groups containing from 1 to 3 carbon atoms, and A denoting …<IMAGE>… …<??>These copolyamides, which can be easily converted by a melt route, make it possible to obtain moulded articles, filaments or films in the case of which an excellent retention of mechanical properties as a function of temperature is observed. |
