| 摘要 |
A polymer foam comprises a rigid foamed wholly aromatic polymer which is capable of forming an anisotropic melt phase and which comprises not less than 10 mole percent or recurring units of the moiety: <CHEM> wherein at least some of the hydrogen atoms present upon the rings may optionally be replaced by substituents selected from alkyl groups of 1 to 4 carbon atoms, alkoxy groups of 1 to 4 carbon atoms, halogen, phenyl, substituted phenyl and mixtures thereof. |
