Fabrication Of The Biodegradable Polyester Elastomer/Graphene Composites

Recently,how to improve the degradadility of polymer material,reduce the consuming of non-renewable resources,and increase its thermal conductivity and electrical conductivity has become an important subject in the field of polymer material.In this paper,we used some biobased monomers derived from renewable resources and graphene oxide to synthesize the biodegradable polyester thermoplastic elastomer/graphene composite materials(BTPE/G)with good thermal and electrical conductivity by in situ melting polycondensation,chemical reduction and chain extender methods as follows.(1)Stripping and reduction of graphene oxide in glycol.We used graphene oxide and 1,4-butanediol to prepare the graphene oxide/1,4-butanediol slurry by magnetic stirring and ultrasonic methods.Then,using solvent thermal reduction and chemical reduction,we make graphene oxide reduce.Digital photo,TEM and AFM prove that the stripped graphene oxide can be dispersed stablely in 1,4-butanediol.Also,the graphene oxide was reduced to graphene was investigated by FTIR,XRD,TGA and EDS,et al.(2)Synthetic and study of soft and hard prepolymer.Using graphene oxide/1,4-butanediol slurry and succinic acid as raw materials,we synthesized the hard prepolymer through in situ melting polycondensation and chemical reduction methods.Using graphene oxide/1,4-butanediol slurry,1,3-propanediol,fumaric acid,succinic acid,and sebacic acid as raw materials,the soft prepolymer was synthesized by in situ melting polycondensation and chemical reduction methods.The molecular structure oftwo kinds of prepolymer were investigated by FTIR and 1HNMR.DSC and POM showed that the addition of graphene made the Tg,Tc and Tm of hard prepolymer increase,meanwhile the size of spherulite decrease and the number of spherulite increase.The addition of graphene aslo made the Tg and Tm of soft prepolymer increase,and the size of spherulite decrease and the number of spherulite increase.(3)Synthetic and study of BTPE/G.Using above two kinds of prepolymer as raw materials and 4,4'-diphenylmethane diisoccyanate as chain extender,we synthesized the BTPE/G by chain extender method.The macromolecular structure of the BTPE/G was investigated by FTIR and 1HNMR.AFM images showed that graphene,soft segment and hard segment existed in the BTPE/G,and the BTPE/G had the obvious phase separation.Moreover,the results of XRD,SEM and TEM proved that graphene were dispersed well in BTPE/G.Further more,the BTPE/G had controllable heat-conducting property(the thermal conductivity are 0.207-0.492W/mK)and conductivity(the electrical conductivity are 10-12-10-5S/m),while the BTPE/G had good thermal performance(Tg is about-40 oC,Tm is above 105 o C,and Td is above358oC),degradation property(the degree of degradation in lipase solution can arrive at94% after 20 days).