Study On The Synthesis Of Poly(Butylene Adipate-Co-Amidoethyl Adipate)Polyesteramide

As one kind of biodegradable materials, Polyesteramides(PEA) has attracted extensive attentions in recent years. But the PEA of high molecular weight is hard to be prepared, so its widely application is limited. In this paper we provide a new method to increase the molecular weight of the polyesteramides in a fast reaction by a chain-extending reaction. Its advantages over conventional polycondensations include the fast reaction, high efficiency, and the easy work-up allowing the use of continuous production processes.In this study, the HO-terminated prepolymer of poly(butylene adipate-co-amidoethyl adipate)(PBEA) was prepared by the polycondensation of adipic acid with ethanolamine and excessive1,4-butanediol. The PBEA pre-polymers with acid number less than1and molecular weight between1500and2000were obtained at a high temperature (180～190℃) and under reduced pressure.10～15%excessive1,4-Butanediol was used and zinc oxide was chose as the best catalyst. At the same time, terephthaloyl biscaprolactamate(TBC) was synthesized and used as chain-extenders for HO-terminated PBEA prepolymer. PBEA with high molecular weight were obtained by the chain-extending reaction with TBC under reduced pressure in bulk state. The influencing factors on the chain-extending reaction were studied. At220℃and TBC/PBEA prepolymer molar ratio of1.1, the PBEA with intrinsic viscosity of1.01dL/g was obtained. The PBEA prepolymer and the chain-extended PBEA were also characterized by GPC and DSC spectra, respectively. The molecular weight of the PBEA after the chain extension was increased evidently but the melting point decreased.Moreover, the influence of the amount of aminoethanol to the properties of PBEA prepolymers and chain-extended PBEA were studied. The polydispersity of chain-extended PBEA were enhanced when the content of aminoethanol increased, so the material might be easier to be processed. When the content of aminoethanol is less than10%, the melting point of PBEA decreased as the content of aminoethanol increasing; when the content of aminoethanol is more than10%, the melting point of PBEA increased as the content of aminoethano increasing.