Structure And Characterization Of Amorphous Starch And Its Blends With PBAT

Due to the traditional use of non-biodegradable plastic seriously polluted the environment also consume oil resources,people’s environmental protection meaning gradually strengthen and non-biodegradable plastic limit and bans the use,biodegradable plastic was the attention of people,materials,design and development meet the expected performance of biodegradable plastics is very meaningful.PBAT and starch can be degraded100% in the natural environment,and their products do not pollute the environment in line with the concept of green development.In this paper,starch is first treated by gelatinization for amorphous processing,and the crystalline structure of starch is destroyed to get gelatinized starch.Glycerin was used as plasticizer to prepare composite materials by melting and blending gelatinized starch（GST）with Polyadipic acid/butylene terephthalate（PBAT）.The blending system of gelatinized starch and PBAT with gelatinized starch as main body and PBAT as filling phase was studied.Its compatibility,crystallization performance,thermal stability and mechanical properties were studied.The compatibility of gelatinized starch and PBAT blend system was studied by using different compatibilizers.Compatibilizer is a new polymer compatibilizer produced by an enterprise,brand name is PVE,tributyl citrate（TBC）,triphenyl phosphite（TPPI）.In addition,PVE was blended with gelatinized starch and PBAT to study the effects of PVE and plasticizer on the compatibility,crystallization properties,thermal stability and mechanical properties of the blend system.The main results are as follows:DSC and XRD analysis showed that PBAT had an effect on the crystallization behavior of the blends,and PBAT could reduce the crystallinity of PBAT.TG and DTG analysis showed that gelatinized starch could reduce the thermal stability of PBAT.The mechanical properties of the composites decreased firstly and then increased with the increase of PBAT content.When the content of PBAT is 30%,the mechanical properties are the lowest,and the tensile strength is 11.66 mpa.Combined with the microscopic morphology analysis,the phase transition point is when the content of PBAT is 30%.The study on the blending system of compatibilizer compatibilizer and PBAT shows that the new compatibilizer PVE can effectively increase the compatibilization of gelatinized starch and PBAT.According to the analysis of microstructure and mechanical properties,PVE can make gelatinized starch particles evenly dispersed in the PBAT matrix,which greatly improves the mechanical properties.Studies on gelatinized starch /PBAT/PVE blend system show that: With the increase of PVE content,the compatibility of composites is getting better and better.When the PVE content is 20%,the mechanical properties of composites reach the maximum and the tensile strength is 30.44 mpa.When the PVE content is more than 20%,PVE has plasticizing effect on PBAT,leading to the decrease of strength.DSC and XRD analysis showed that PVE and PBAT had an effect on the crystallization behavior of the blends.PVE could promote the gelatinized starch and reduce the crystallinity of PBAT.With the increase of glycerol content,the mechanical strength of the composite increases first and then decreases.When the glycerol content is 40%,the mechanical strength of the composite reaches a maximum of31.66 MPa.When the glycerol content is more than 40%,the glycerol overplasticizes the starch and the strength decreases.Through DSC and XRD analysis,glycerol and PBAT have an effect on the crystallization behavior of the blend system.Glycerol plasticization reduces the crystallization performance of starch and starch hinders the crystallization process of PBAT,resulting in decreased crystallinity.