Study On The Modification Copolyolefin Thermoplastic Elastomer By Constructing Hydrogen Bonding/Coordination Sacrificial Network

Thermoplastic elastomers(TPE)are the third-generation rubber after the natural rubber and synthetic rubber.It combines the advantages of high elasticity of vulcanized rubber and the plasticity of plastics.TPE not only exhibit low density,good thermal stability and chemical resistance,but also have the advantages of convenient processing,high production efficiency and low cost,which is in accord with green chemistry.TPE are the high promising substitute for traditional vulcanized rubber and they have been widely applied in automotive,construction,medical,shoemaking,etc.The strength and toughness of TPE could not simultaneously reach the possibility of being used as engineering materials,which limits their application.The realization of high mechanical strength in TPE usually comes at the expense of low toughness in terms of resilience and stretchability.Therefore,the preparation of TPE with high mechanical strength-toughness combination remain a challenge.In this study,highperformance TPE with high strength-toughness combination were prepared.The main research work are as follows.(1)Maleic anhydride modified SEBS,3-amino-1,2,4-triazole(ATA),zinc acetate and SEBS were multi-step mixed to obtain ZASM/SEBS composites.The FT-IR spectra and XPS measurement were carried out to characterize the formation of Zn-based coordination bonds and hydrogen bonds in ZASM/SEBS composites.The tensile properties,thermal stability and transparency of ZASM/SEBS composites were charactered by tensile testing,thermal aging testing,scanning electron microscope,thermogravimetric analysis,etc.The results demonstrated that the amide triazole-carboxylic acid groups converting from the maleic anhydride were grafted on the chains of SEBS-g-MA,which could function as ligands for metal-ligand coordination and hydrogen bonding.The successful introduction of the Zn-based coordination and hydrogen bonding dual-dynamic network could significantly improved the strength,toughness and mechanical strength-toughness combination of ZASM/SEBS composites.For ZASM/SEBS composites,the tensile strength and elongation at break of ZASM/SEBS composites firstly increased and then decreased with the decreasing mass ratio of ZASM.The tensile strength reached 32.1 MPa along with the elongation at break of 1383 %for ZASM-30,which exhibited the optimal mechanical strength-toughness combination.In addition,ZASM/SEBS composites exhibited excellent transparency.(2)SEBS-g-MA and ethanolamine were reacted to obtain EASM,followed by blending with olefinic block copolymer(OBC)to obtain EASM.Then,EASM with various mass ratio loadings of OBC were melt-blended to prepared EASM/OBC composites.The FT-IR spectra was carried out to characterize the formation of hydrogen bonds in EASM/OBC composites.The result indicated that the maleic anhydride group in SEBS-g-MA reacted with ethanolamine to introduce hydroxyl,which could function as ligands for hydrogen bonding network in EASM/OBC composites.The tensile properties and thermal stability of EASM/OBC composites were charactered by tensile testing,SEM and DSC.The results showed that the successful introduction of hydrogen bonds in EASM/OBC composites significantly improved the strength and toughness of composites.For EASM/OBC composites,the tensile strength and elongation at break of EASM/OBC composites firstly increased and then decreased with the decreasing mass ratio of EASM.The tensile strength reached 18.3MPa along with the elongation at break of 971 % for EASM-20,which exhibited the optimal mechanical strength-toughness combination.In addition,EASM/OBC composites exhibited improved thermal stability and excellent transparency.