Study On Structure And Properties Of PLA/PHBV/GO Composite And Its Melt Blown Nonwovens

At present,the raw materials of the melt blown nonwovens are mainly polyester(PET)and polypropylene(PP).These petroleum based materials not only consume a lot of energy,but also can't be biodegraded after be abandoned,resulting in a double burden on energy and environment.As people pay more and more attention to energy and environmental protection,the biodegradable materials have become a focus of research.Polylactic acid(PLA)and poly(3-hydroxy butyric acid-co-3-hydroxy ester)(PHBV)materials are widely researched and applied in many environment-friendly materials.Therefore,PLA/PHBV/graphene oxide(PLA/PHBV/GO)composites were prepared in this paper,in which PLA was the matrix,PHBV was toughening material and GO was used as compatibilizer,Furthurmore,the melt blown nonwovens were prepared by use of the PLA/PHBV/GO composites,and the structure and properties of these melt blown nonwovens were studied,It is hoped that our studies can provide a theoretical basis for the development of medical products and filter melt blown nonwoven materials.PLA/PHBV/GO composites with different mass ratio were prepared by melt blending method.The morphology,thermal properties,crystallization and mechanical properties of the composites were studied by SEM,DSC,XRD and the universal material testing machine.The results showed that the GO lamellae was interspersed in PLA matrix and dispersed uniformly,indicating that GO could improve the miscibility between PLA and PHBV.The existence of GO plays a heterogeneous nucleation effect on the crystallization of PLA.The addition of GO reduced the crystallization temperature of PLA and improved the crystallinity of the composite,but did not change the crystalline structure of PLA.The addition of GO increased the elongation at break of the composites,but led to the decreasing in the tensile strength of the composites.In view of the comprehensive mechanical properties of the composites,when the content of GO is 0.25 wt% and 0.5 wt%,the composites not only have higher elongation at break,but also maintain a certain tensile strength.The biodegradability of PLA/PHBV/GO composites with different mass ratios was studied.The mass loss rate,water absorption rate,surface morphology,crystalline structure and thermal properties in the buffer solution with different pH were analyzed before and after degradation.The results showed that the mass loss rate and water absorption of PLA/PHBV/GO blends increased at the fastest speed in alkaline buffer,followed by in the acidity and neutral solution.The addition of PHBV promote the degradation of PLA in alkaline buffer,and had a hindrance effect in the acidic and neutral buffers.Moreover,the addition of GO slightly promoted the degradation of the blends.With the increasing in the degradation time the crystallinity of the composites,the crystallinity of the composites increaseed firstly and then decreases.However,the crystalline structure of the composites did not change.The melting temperature of the composites shifted to the low temperature after degradation.PLA/PHBV/GO melt-blown nonwovens with the different mass ratios were prepared by melt-blown nonwoven technology.The surface fiber morphology,pore size distribution,permeability,filtration performance,thermal properties,mechanical properties and antibacterial properties of PLA/PHBV/GO nonwovens were analyzed respectively with SEM,the aperture distribution meter,the air permeability meter,the high efficiency filter test bench,DSC,the universal material testing machine and the bacteriostasis method.The results showed that the structure of PLA/PHBV/GO melt blown nonwovens were more loose,the average fiber diameter and the pore diameter were larger than pure PLA melt blown nonwovens.The permeability of PLA/PHBV/GO melt blown nonwovens was better than that of pure PLA melt blown nonwovens,but the filtration efficiency was poorer than that of PLA.The tensile strength of PLA/PHBV/GO melt blown nonwoven material was lower than that of pure PLA melt blown nonwoven material,but their elongation at break was increased.All components melt blown nonwovens had no obvious antibacterial effect on Escherichia coli,but the melt blown nonwovens with mass ratio of 90/10/0.5 had better antibacterial effect on Staphylococcus aureus.