Research On Materials For Biodegradable PBAT Film And Their Related Properties

At present,white pollution has become more and more serious,then people's awareness of environmental protection has raised.Disposable plastic products such as Low Density Polyethylene(LDPE)film is restricted,the current hot topic is the development of a fully biodegradable film to replace LDPE film.In this work,the recipe of materials,basic physical properties and molding process of the poly(butylene adipate-co-terephthalate)(PBAT)fully biodegradable film were studied.PBAT/PBS blend material was obtained by blending fully biodegradable material poly(butylene succinate)(PBS)and PBAT PBAT/PBS.The Melting Strength(Ms)of PBAT/PBS blends has been improved by adding chain extender.Better fully biodegradability PBAT/PBS/starch blend material has been prepared by adding starch,and blown it into a film.In the first period,PBAT/PBS blend material was prepared by melt blending,and discussed the effect of addition of long chain hyperbranched chain extender(LCMAH)on Melting Strength of PBAT/PBS blend material,and crystallization performance,thermal stability performance,mechanical properties of PBAT/PBS films.The results showed that PBS effectively improved the mechanical properties of PBAT/PBS blended materials.When the PBS addition was 15%,the tensile strength of the PBS/PBAT blend material reached 26.5MPa.After adding LCMAH,the molecular weight and the number of branched chains of PBAT/PBS blends has increased.When the LCMAH addition was 1.5%,the melting strength of the PBAT/PBS blend material increased by 7.03KPa·s,while the crystallinity of PBAT and PBS are 1.3% and 12.7%at present,respectively.The initial thermal decomposition tempera DDRe increased by11.64?,a new thermal weight loss process appeared at 450?.The transverse and longitudinal tensile strength of the PBAT/PBS blend material reached 32.6MPa,28 MPa,the transverse and longitudinal elongation at break reached 950.4%,493.2%,and the transverse and longitudinal right-angle tear strength reached 259.6k N·m,249.6 k N·m.The tear strength of horizontal and vertical trousers has reached 129.7k N·m,124.7k N·m,respectively.In the second period,for shorten the degradation time of the film,the Thermoplastic Starch(TPS)has added to the PBAT/PBS/LCMAH blend material.The relationship between the addition of glycerol(Gl)in TPS(1.25%,2.5%,3.75%,5%)and the compatibility of materials has researched.The effect of the addition of glycerol on the crystallization,thermal stability,and mechanical properties of film has researched too.The results showed that when the Gl content was 5%,the plasticizing effect on starch was the best,and the compatibility with the PBAT/PBS/LCMAH has significantly improved.Compared with the unplasticized starch,the initial thermal decomposition tempera DDRe of the film has increased by 35 ?,the crystallinity of PBAT and PBS were 0.6% and 12.3%,respectively;the transverse and longitudinal tensile strengths of the film were 22 MPa and 23.1MPa,respectively.In the last period,PBAT/PBS/LCMAH/TPS films with different blow-up ratio(BUR)and draw-down ratio(DDR)were prepared by up-blowing film blowing process and their properties were studied.The results showed that the difference of mechanical properties in transverse and longitudinal directions was caused by the different values of BUR and DDR.Considered from crystallization,due to the difference in process parameters,the crystallinity,crystal distribution and crystal morphology of the film has changed,which lead to different mechanical properties in the transverse and longitudinal directions of the film.