Synthesis And Properties Of Biodegradable Polyester Ureide Multiblock Copolymers

A series of polyester ureide multiblock copolymers with different feed composition have been synthesised with toluene-2,4-diisocyanate(TDI)as a chain extender by melt polymerization.Different feed composition of biodegradable block copolymer was prepared into films by the plate vulcanizing machine.The properties of copolymers and films were studied.The main researches are as follows:Poly(butylene-succinate-urea)(PBSu)and poly(adipate-succinate-ura)(PBAu)has been successfully synthesized with succinic acid(SA),adipic acid(AA),1,4-butanediol(BDO)and urea(UR)as the main raw material.The molecular weight of PBSu and PBAu is 10.9×10~3 and13.96×10~3 respectively.Biodegradable polyester ureide multiblock copolymers(PBSu-co-PBAu)composed of poly(butylene-succinate-urea)(PBSu)and poly(adipate-succinate-uera)(PBAu)will be synthesized with toluene-2,4-diisocyanate(TDI)as a chain extender by melt polymerization.Study the influence of polymerization time,temperature and addition of toluene-2,4-diisocyanate(TDI)on the chain-extension.Though the single factor synthesis to get the best polymerization conditions that the polymerization time,temperature and addition of toluene-2,4-diisocyanate(TDI)is 4.5 hours,130 o C and 6 percent respectively.A series of polyester ureide multiblock copolymers with different feed composition that mass ratio of PBSu to PBAu are 100:0?90:10?70:30?50:50?30:70?10:90?0:100 respectively have been synthesized according to the best polymerization conditions.Polyester ureide multiblock copolymers possessed higher melting temperature than the polyester ureide random copolymers.And possessed more excellent thermal stability.its initial decomposition temperature(T_d)range from359? to 365?,far higher than its processing temperature(120?-120?).The apparent viscosity of polyester ureide multiblock copolymers is higher than the homopolymer.And possessed better elasticity effect than the homopolymer.Different feed composition of biodegradable block copolymer was prepared into films by the plate vulcanizing machine.With the increase ofthe content of PBAu,The elongation at break of polyester ureide multiblock copolymer films increased.When the content of PBAu ranges from 70% to 90%,the polyester ureide multiblock copolymer films possessed excellent toughness and high tensile strength.The biodegradable properties,oxygen barrier properties and the luminousness of polyester ureide multiblock copolymer films are related to the degree of crystallinity.With the decrease of crystallinity,The oxygen barrier properties of polyester ureide multiblock copolymer films decreased.But the biodegradable properties and the luminousness of polyester ureide multiblock copolymer films increased.