Two series of polyesters have been synthesized, one based on terephthalic a
cid and the other based on 2,6-naphthalene-dicarboxylic acid. Three diols w
ere used: ethylene glycol, 1,4-butanediol and 1,10-decanediol. The polymers
have been characterized and their thermal and radiation stabilities examin
ed. The temperatures for 5% weight loss at a scanning rate of 20 degrees C
min(-1) were in the range 376-424 degrees C. The stability of the polyester
s decreased as the number of carbon atoms in the aliphatic diol increased,
and the terephthalate polymers were not as stable as the naphthalate-based
polymers. On radiolysis at 77 K about 50% of the radicals formed were anion
radicals, with the total radical yields in the range 0.19-0.41 for the pht
halate polyesters and in the range 0.08-0.12 for the naphthalate-based poly
mers. The radical yields increased with an increasing number of carbon atom
s in the diol units. Radiolysis at 298 K produced radical yields in the ran
ge 0.02-0.06 for the phthalate polyesters and in the range 0.01-0.05 for th
e naphthalate-based polymers. (C) 1999 Society of Chemical Industry.