Synthesis,Crystallization Behavior And Properties Of Poly(Butylene Succinate-co-1,2-decadiene Succinate) Copolyesters

In recent years,with the successive promulgation of plastic restriction and plastic ban,biodegradable polymers are gaining wider attention.poly(butylene succinate)(PBS)is considered to be one of the most promising biodegradable polymers,but the disadvantages of poor toughness and slow crystallization rate of PBS limit its large-scale application.Therefore,in this thesis,we first synthesized several branched poly(butylene succinate-co-1,2-decadiene succinate)copolymers by a copolymerization in method order to overcome the shortcomings of PBS and then systematically investigated the effect of side chains on the properties of these copolyester.Composite materials were further prepared with modified multi-walled carbon nanotubes(f-MWCNTs).The main conclusions of this thesis are as follow.1.A series of PBDS copolymers were synthesized by a condensation polymerization method.The results showed that the introduction of side chains weakened the crystallization ability of PBDS;consequently,the crystallization rate and crystallinity of PBDS were lower than those of PBS.However the crystallization mechanism and crystal structure of PBDS were exactly the same as those of PBS.The introduction of side chains significantly improved the toughness of PBDS.2.To better understand the relationship between molecular structure and properties,PBES20,which had the same main chain structure as PBDS,was synthesized.PBDS copolymers had a weaker crystallization ability than liner PBES due to the poorer molecular chain regularity of PBDS20.However,the toughness of PBDS20 was better than that of PBES20.3.PBDS20/f-MWCNTs composites were prepared by a solution casting method.The addition of f-MWCNTs significantly improved the crystallization performance of the PBDS copolymers;therefore,the crystallization rate of PBDS20 was also significantly enhanced.Dynamic mechanical experiments also demonstrated that the storage modulus of the composites was also significantly improved.In sum,in this thesis we explored different methods of modifying PBS from the perspective of structure and performance,and systematically investigated the effect of branched structure on the performance,which should be important for the performance regulation and practical application of PBS.