Copolyester-ether polymers

Abstract

A segmented copolyester-ether polymer comprises 9.5 to 33 percent by weight hard segment residues of polybutylene terephthalate and 0.5 to 67 percent by weight soft segment residues of a polyether polyol comprised of n units of residue (1) and m units of residue (2), wherein the total value of n+m is in the range 2 to 70, m/(n+m) is in the range 0.05 to 0.98, and residues (1) and (2) have the structures: ##STR1## The polyether polyol is further characterized in that at least 95 percent of the hydroxyl groups are primary hydroxyl groups.

We claim: 
     
       1. A segmented copolyester-ether polymer comprising: (a) 99.5 to 33 percent by weight hard segment residues of polybutylene terephthalate and   (b) 0.5 to 67 percent by weight soft segment residues of a polyether polyol comprising: (i) n units of residue (1) having the formula: ##STR7## and (ii) m units of residue (2) having the formula: ##STR8## wherein the total value of n+m is in the range 2 to 70, m/(n+m) is in the range 0.05 to 0.98.     
     
     
       2. The segmented copolyester-ether polymer of claim 1 wherein the polyether polyol has at least 95 percent primary terminal hydroxyl groups. 
     
     
       3. The segmented copolyester-ether polymer of claim 1 prepared by melt condensation polymerization.