Effect of maleic anhydride graft-modified ground tire rubber on properties of poly(lactic acid)
Maleic anhydride(MAH)was grafted onto the surface of waste rubber powder(GTR)to obtain GTR-g-MAH(MGTR)using benzoyl peroxide as an initiator.Poly(lactic acid)(PLA)/MGTR blends were prepared through melt blending,and their micromorphology,crystallization behavior,and mechanical properties were thoroughly investigated.As a result of successful grafting of MAH onto GTR,the MGTR particles were uniformly distributed in the PLA matrix due to good phase compatibility.Additionally,MGTR could facilitate the crystallization of PLA and the formation of more perfect crystals.The tensile strength of the PLA/MGTR blends decreased with an increase in the MGTR content,while their elongation at break and impact strength exhibited an increasing trend at first and then a decrease.The blends containing 10 wt%MGTR exhibited the highest crystallinity of 16.4%,which is 7 times that of pure PLA.With 15 wt%MGTR was incorporated,the blends showed the highest elongation at break and impact strength,which were 30%and 60%greater than those of pure PLA,respectively.This allowed the blends to maintain good tensile strength and also resulted in effective toughening for PLA.