Influence Of MPEG And Composition On The Microstructure And Properties Of PBS-based Blends

Blend of PBS plays an important role in reducing the costs and improving itsperformance. However, due to the high crystallinity of PBS and poor compatibilitywith other degradable materials, the performance of the materials decreased. In thisarticle, PBS/PPC and PBS/starch were obtained by melting blend method. Influenceof the MPEG-2000content and its composition on the microstructure and properties（mechanical and thermal performance） of PBS-based blends were investigated. Theresults obtained as following:（1） FTIR rest of PBS/PPC blends shows that the introduction of MPEG canenhance the interfacial bonding between the two phases via hydrogen bonds. Themechanical properties test results show that the instruction of MPEG can improve thecompatibility of the blended materials. The SEM shows that the introduction ofMPEG can improve the interfacial bonding strength of two phases and initiate thematrix materials multiple crazing and shear deformation, it seems that the blend ownsgood toughness characteristics. The fracture behavior analysis shows that5%of theMPEG can increase the fibrosis density of the blends in the state of micro-cracks,leading to the PBS/PPC/MPEG blended materials exhibiting a higher impactrisistance.DSC of PBS/PPC/MPEG blends show that5%of MPEG makes the crystallinityincrease from43.1%to48%, and the crystallization temperature T_c,p increased8.2℃. TGA reveals that the introduction of MPEG could elevate apparent activationenergy for thermal decomposition of PBS/PPC blends, and the thermal stability hasbeen improved.（2） The results of mechanical property of PBS/starch blends test show that theintroduction of starch makes the impact/tensile strength of the blends dramaticallyreduces and exhibits a brittle fracture characteristic. Introduction of MPEG couldimprove the compatibility of the blends. With5%MPEG （PBS/starch=70/30）, thestrength of tensile reaches14.5MPa, with10%MPEG, the strength of impactreached the max value of9.2KJ/m². SEM of the impact farcture show that the introduction of MPEG can improve the interfacial bonding strength of two phases,leading the impact strength of PBS/starch/MPEG improved. Analysis on the fracturebehavior shows that the critical strain energy release rate, G_in,, of blended materialsdecreases with increasing content of MPEG. Therefore, the material on the crack thesensitivity was enhanced.The DSC results show that the starch could improve the crystallinity of PBS. Whenthe content of MPEG was20%, the crystallinity of PBS/starch MPEG increased from40.9%to47.8%, crystallization temperature T_c,p decreases6.4℃and the degree ofsupercooling increased to42.6℃. TGA reveals that the induction of MPEG hasseldom influence on the apparent activation energy and T_p of the thermal de-composition of PBS/starch at high-temperature region.