| 摘要 |
<p>Segment type thermoplastic copolyesters consist of a large no. of recurring long chain ester and 66-95 wt.% short chain ester units joined together in a head-to-tail manner by ester gps. and where long chain ester units have structure: and short chain units have structure: (where G is bivalent residual radical remaining after terminal OH gp. elimination from poly (alkyene oxide) glycol of mol. wt. 400-4000 and C:O ratio of 2.0-4.3; R is bivalent radical remaining after COOH gp. elimination from dicarboxylic acid of mol.wt. =300 and D is as G except that OH gps. are from a diol of mol. wt. =250). These copolymers have low viscosity when warm, high thermal stability, good flow characteristics, rapid setting time, etc., making them suitable for moulding and extruding operations. They can be used to make films, pipes, tubes, etc.</p> |
