Research On Materials For Biodegradable PBAT Film And Their Related Properties

Polybutylene adipate/terephthalate(PBAT)is a fully biodegradable material with excellent properties and has the potential to replace traditional non-degradable LDPE materials.The high cost of PBAT material limits its application range,and it usually needs to be modified to compensate for its shortcomings.In this paper,different thermoplastic starches(GTPS,UTPS,GUTPS)were prepared by using glycerin(glycerin),urea(urea)and their mixtures as plasticizers to improve starch processing properties.Then TPS and PBAT are blended to produce different PBAT/TPS materials to reduce the cost of PBAT materials.A group of plasticizer systems with better plasticizing effect were selected to prepare PBAT/TPS.On this basis,by introducing maleic anhydride(MA)and benzoyl peroxide(BPO)into the PBAT/TPS system to improve the melt strength of the blended material and improve the compatibility of TPS and PBAT,and the effects of different MA additions on the properties of PBAT/TPSMA blends were investigated.The effect of content on the properties of PBAT/TPS-MA system.Finally,the material was extruded and blown into a film,and the effect of the blown film process and the content of TPS-MA on the properties of the blended film was investigated.The following conclusions are drawn:The addition of plasticizer improves the processing performance of TPS.Using glycerol and urea as composite plasticizers to plasticize starch has better plasticizing effect than using single plasticizer,and more stable hydrogen bonds are formed between GUTPS systems.Scanning electron microscope and mechanical properties test show that co-plasticization of glycerol and urea can reduce the low agglomeration effect of each other,help to improve the dispersibility of TPS in the PBAT matrix,and reduce the average dispersion size of TPS particles in the PBAT matrix.The dispersibility of GUTPS in PBAT matrix is better than that of GTPS and UTPS.The tensile strength of PBAT/GUTPS(1:2)material is 14.3 MPa,which is 2.8 MPa higher than that of PBAT/GTPS,and the elongation at break is 735%,which is 54.7% higher than that of PBAT/GTPS.MA modified PBAT/TPS system improved the melt strength of the material and also improved the compatibility of PBAT and TPS-MA two phases.Ms test,DSC test,scanning electron microscope(SEM)and mechanical properties test show that it is more appropriate to add 1% MA to the starch masterbatch.The processing and forming properties of PBAT/TPS-MA-1 are improved,and the melt strength of the material is984Pa·s,which is 278% higher than that of PBAT/TPS.The average particle size of TPS-MA-1 in PBAT was significantly reduced,which reduced the stress concentration during the stretching of the blend system and improved the tensile properties of the blend.The tensile strength of PBAT/TPS-MA-1 is 15.4 MPa and the elongation at break is 966%,which are 7.7% and 31.4% higher than that of PBAT/TPS,respectively.Changing the process parameters of the blown film can affect the mechanical properties of the film.When the drawing speed of the PBAT/TPS-MA-1 blown film forming process is 5-6r/min and the inflation ratio is 3.2,the film performance is better.The mechanical properties of PBAT/TPS-MA-1 decreased with the increase of TPSMA-1 content.The PBAT/TPS-MA-1(60/40)film was comprehensively excellent,and its longitudinal and transverse tensile strength was 15.7MPa/13.6 MPa,elongation at break 845%/628%,has the potential to replace traditional PE film.