{HEAD ~ Preferred polyesters} have the formula; ##STR1## wherein each R1 is a 1,4 phenylene moiety; the R2 are essentially ethylene moieties, {TAIL ~ 1,2 propylene moieties} or a mixture thereof; each X is ethyl or preferably methyl; each n1 is from 1 to about 5; the sum of each n1 +n2 is from about 12 to about 43; u is from about 3 to about 10 
{ HEAD ~ Preferred polyesters } have the formula ; # # STR1 # # wherein each R1 is a 1,4 phenylene moiety ; the R2 are essentially ethylene moieties , { TAIL ~ 1,2 propylene moieties } or a mixture thereof ; each X is ethyl or preferably methyl ; each n1 is from 1 to about 5 ; the sum of each n1 + n2 is from about 12 to about 43 ; u is from about 3 to about 10
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