Synthesis And Properties Of Functionalized PBS Polyesters

With the depletion of petroleum resources and severely environmental pollution,the research and development of biodegradable material has attracted more and more attention.Poly(butylene succinate)(PBS)has also been known as an important biodegradable aliphatic polyester and has attracted much interest,because of its good degradation property,excellent processability and physical property.However,the product of PBS has limited its further application owing to its high hydrophobicity and crystallinity as well as low degradation rate.Therefore,we want to modify the PBS by introducing different third modified monomers to improve the performance of PBS and provide PBS with new unique characters.In this paper,a series of functionalized PBS-based polyesters were synthesized by adding malic acid,N-acetyl-L-glutamic acid and 2.6-pyridinedicarboxylic acid,and the crystallization,thermal stability and degradation properties of the PBS were characterized.Firstly,a serials of biodegradable co-polyester of poly(butylene succinate-co-butylene malate)(P(BS-co-BM))bearing hydroxyl groups was successfully synthesized without hydroxy-protection.The synthesized co-polyester has good thermal stability.Compared with neat PBS,the glass transition temperature of P(BS-co-BM)increases to-26.1? and the crystallization property decreases with the increase of malic acid content.The water contact angle decrease to 40.6°,and the P(BS-co-BM)co-polyester has good hydrophilic property and the enzymatic degradation rate increased.The P(BS-co-BM)co-polyester was blended with commercial PBS,and the elongation at break of the blend increased by 100%.The synthesized co-polyesters has a certain toughening effect on PBS.Secondly,the bio-based N-acetyl-L-glutamatic acid has been used to obtain biodegradable co-polyesters of poly(butylene succinate-co-N-acetylglutamate)(P(BS-co-BGA))bearing acetylamino group through polycondensation.The synthesized co-polyester has good thermal stability,Compared with PBS,the crystallization temperature and melting point of P(BS-co-BGA)gradually decrease,the crystallization temperature decreases from 80.2? to 58?,the melting point decreases from 112.4? to 96.7?,the enzymatic degradation rate increased,the spherulite size gradually decreased and nucleation efficiency improved with the increase of N-acetyl-L-glumatic acid content.Thirdly,Antibacterial multiblock co-polyester PBS-b-PBD bearing Pyridinium salts side groups were successfully synthesized by melt polycondensation,chain-extension of prepolymer mixture and Alkylation grafting method using succinic acid(SA),1,4-butanediol(1,4-BD),2,6-pyridinedicarboxylic acid(DAff),isophorone diisocyanate(IPDI)and bromobutane.The results show that,the crystallization temperature of PBS-b-PBD multiblock co-polyester is reduced from 72.2? to 61.7? with the increasing of PBD content,weight loss does not take place for all synthesized polymers before 300?.The co-polyester has good thermal stability.The inhibition zone of E.coli and S.aureus was obvious when the Br element content increased to 1.64%or more,which indicates that the co-polyester had good antibacterial activities.