SYNTHESIS OF POLYESTERAMIDES FROM N,N''-BIS(2-HYDROXYETHYL)-TEREPHTHALAMIDE AND CHAIN EXTENSION REACTION
由对苯二甲酰胺二醇合成聚酯酰胺及其扩链反应的研究

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.Chainextension 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)prepolymem 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 T_g of PEA(80/20)increased,and its △H_m as well as T_m decreased.PEA(0/100)is a non-crystallizable polyesteramide,and its T_g 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.