Polyesteramide (PEA(x/y)) prepolymers with intrinsic viscosity from 0.24 dL/g to 0.52 dL/g were synthesized through melt condensation polymerization from adipic acid

butanediol and N

N′-bis(2-hydroxyethyl)terephthalamide (HETA) at different butanediol (x) to HETA (y) molar ratios.Chain extension reaction was performed with 2

2′-(1

4-phenylene)-bis(2-oxazoline) (PBOX) or adipoyl biscaprolactamate (ABC) alone

or with combined PBOX +ABC chain extenders.High molecular weight PEA with intrinsic viscosity of 1.05 and 0.73 dL/g was obtained when PEA(90/10) and PEA(80/20) prepolymers were chain extended.The PEA prepolymers and the chain extended PEA were characterized by FTIR and 1H-NMR spectroscopy

differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).1H-NMR spectra revealed that during the preparation of PEA prepolymers

esteramide exchange side reaction took place.DSC studies indicated that after chain extension

the Tg of PEA(80/20) increased

and its ΔHm as well as Tm decreased.PEA(0/100) is a non-crystallizable polyesteramide

and its Tg is 65℃.TGA studies showed that as the content of HETA used in the synthesis of PEA(x/y) prepolymers increased

the thermal stability of the prepolymers decreased

because the introduced terephthalic diesterdiamide showed less stability