摘要 |
<p>Aramid polymers with small amounts of alkyl-and/or alkoxy-substitution on their aromatic diamine and/or aromatic diacid monomeric units are disclosed. Such aramid polymers show improved properties compared to similar aramids without the substitution. The aramids described herein are useful for films or fibers, for example, as employed in the manufacture of packaging, ropes, filter bags, or composites. The invention also includes a process for making such polymers, involving subjecting fibers or films made from such aramid polymers to heat treatment under tension.</p> |