Study On The Performance Of Office Wastepaper Fiber Reinforc-ed PLA/PBAT Degradable Composites

Poly(lactic acid)(PLA)has attracted much attention in the field of biodegradable materials due to its excellent biodegradability.However,its brittleness and relatively high price limit its application field.Poly(butylene adipate-co-terephthalate)(PBAT)also has excellent degradation performance and strong toughness,which can be applied to film products.Office wastepaper fiber(OWF)is a kind of environmental fiber with simple source but poor application.It has the advantages of high specific strength,high specific modulus and low cost similar to plant fiber.Therefore,using PLA,PBAT and OWF as raw materials,a new biodegradable composite material was prepared,which has practical significance for expanding the application scope of PLA,promoting the resource utilization of wastepaper fiber,reducing environmental pollution and alleviating energy crisis.In this paper,composite materials were prepared from office wastepaper fiber and PLA.The reinforcing effects of wheat straw fiber,bamboo fiber and waste paper fiber on PLA composite materials were compared,and the PLA/PBAT/wastepaper fiber composite system was preliminarily studied.The research results show that:(1)Compared with the enhancement effect of WSF,BF and OWF on PLA composite,the PLA/OWF composite has the best mechanical and thermal stability.When the addition amount of OWF was 20 wt%,the tensile strength and flexural modulus of PLA/OWF composites were improved by 3.2%and 14.1%respectively.Scanning electron microscopy pictures revealed that the OWF fiber was most closely bound to the PLA matrix.(2)FTIR showed that OWF modified by KH550,KH560 and KH570 were grafted successfully.The tensile strength,flexural strength and flexural modulus of PLA/OWF20 composite were improved most obviously by KH560.According to the TGA curve,the KH560 modified PLA/OWF20 composite has the best thermal stability.(3)When the amount of MAPLA was 2 wt%,the mechanical properties of PLA/30PBAT composites were enhanced most obviously.The addition of PBAT will reduce the crystallinity of the composite to some extent,but improve its thermal stability.It is known from the crystallization and melting properties that MAPLA can act as nucleating agent and improve the crystallinity of the composites.(4)When the content of PBAT was 20 wt%,the notch impact strength of PLA/PBAT/OWF composite was the highest,reaching 17.6 KJ/m2,which is 291%higher than that of pure PLA.As can be seen from the crystallization and melting properties,OWF can promote the crystallization of composite materials and improve the crystallization performance,while PBAT can prevent the crystallization and the higher the content is,the more obvious it is.(5)MAPLA can improve the impact toughness and crystallinity of PLA/20PBAT/OWF composites.The tensile strength,flexural strength and flexural modulus of PLA/20PBAT/OWF composites modified by KH560 and MAPLA were the best.SEM diagram shows that when MAPLA and KH560 are added to the composite at the same time,the interface bond of composite is the closest.