Thermoplastic elastomers of the poly[ester-b-ether] copolymer type (PEE) co
mprising a hard block of poly(butylene terephthalate) (PBT) and oligoether
soft segments, differing in the molecular weight of the oligoether [alpha,o
mega-dihydroxy poly(oxytetramethylene) (PTMO); M-n = 650, 1000, and 2900 g/
mol] were synthesized and analyzed. Synthesized PEEs were modified by a dim
er fatty acid (DFA, M-n = 570 g/mol) as a component of the soft segments. E
ach copolymer (consisting of one hard-segment component and two components
of the soft segments) was obtained in a two-stage process involving transes
terification and polycondensation in the melt. Elastomer series were prepar
ed with a constant PET mass ratio of 50; the content of PTMO and DFA segmen
ts was changed. Differential scanning colorimetry results showed a single g
lass transition temperature for the mixed PTMO-DFA soft phase, which indica
tes that ether and aliphatic units are able to create a homogenous amorphou
s phase.