The Preparation And Performance Of Biodegradable Polyester Amide Copolymers

In order to prove the usability of biodegradable plastic,a new type of polyester amide copolymers were successfully synthesized by polycondensation reaction in this paper, and their processes of synthesis and all aspects of properities were analyzed.(1) A series of poly(butylene succinic-co-butylene hexamethylenediamine) copolyesters were synthesized from succinic acid,butyl glycol, 1,6- hexamethylenediamine through polycondensation reaction.The researches showed that with n(butyl glycol + 1, 6 hexamethylenediamine) : n succinic acid = 1.3:1, adding 0.3 wt% of catalyst dibutyl tin laurate, the esterification temperature was 180 ℃ and the reaction time between 8 h, the polycondensation temperature was 235 ℃ and the reaction time between 5 h,the molecular weight of polyester amide prepolymers was highest. The best chain extension process was adding 5 wt% of TDI, the chain extension temperature was 130 ℃ and reaction time was 4 h, the properties of polyester amide copolymers were best.(2) The copolymers were prepared for film, and the molecular weight ranged from 5.4 × 104 to 6.5 × 104. With the increasing of amine, the melting point,crystallization temperature and thermal decomposition temperature of copolymers decreased. The introduction of 1, 6-hexamethylenediamine improved the degradation property of polymer. The tensile strength of the polymers film was also improved. When the amine content was 10 %, the tensile strength of polymer film reached to 39.7 MPa, but the elongation at break decreased. From the thinking of thermal properties and mechanical properties of copolymer, when amine content was 6 %, the comprehensive properties of copolyesters were best.(3) The poly(butylene succinic-co-butylene hexamethylenediamine) copolyesters were modified by branched chain. Branched chain decreased the thermal stability of copolymers slightly and improved the degradation property. When the content of branched chain was 1:6, the melt temperature was 104.79 ℃ and the decomposition temperature was 352.39 ℃, the tensile strength was 27.91 MPa, the elongation at break was 721.76 %. In a word, the comprehensive properties of polymer film achieved the best.(4) Theological test was used to guide the processing of polymers. The influence of content of branched chain on the viscosity, energy storage modulus and shear stress was studied by rotational rheometer. And the best processing technology were determined. The increase of the content branched chain reduces the viscosity of polymers, the storage modulus of was greately influenced by shear rate, and shear stress was influenced by shear rate a little. When the content of branch chain was less than 1:6, the tensile strength and elongation at break increased as the temperature rise. With the increase of content of branched chain, the properties of copolymers were affected by the temperature a little.