262 HIGH PERFORMANCE POLYMERS
naphthalate, respectively, by a melt condensation
technique, distilling off ethylene glycol [38]. Zinc
acetate and antimony trioxide were used as catalysts.
The copolyesters were extensively characterized with
respect to intrinsic viscosities, solubilities, thermal
properties, and, moisture absorption. Details can be
found in the literature [38].
11.2.2.2 Poly(ether ester) Elastomers
Block poly(ether ester) (PEE) elastomers are syn-
thesized with DMT and NDC. Alcohol compo-
nents are 1,4-butanediol, and poly(tetramethylene
ether) glycol of a molecular weight of 1000.
Poly(tetramethylene ether glycol terephthalate) units
are functional as the soft segment in the block struc-
tures. The introduction of the 2,6-NDA group into