Utilization of ultrafine acrylate rubber particles as a toughening agent for poly(lactic acid)

The present research aims to utilize ultrafine elastomeric particles to reduce the problem of brittleness in poly(lactic acid) (PLA). Particles of acrylate rubber were added to PLA at the range from 0.1 to 10 wt%. Maximum reduction of the flexural modulus and the tensile modulus was achieved by 20 and 45% respectively when the acrylate rubber was applied at 10 wt%. The tensile elongation at break of the rubber-modified PLA was also raised around 50 times from the 3.5% observed in the neat PLA to 200%. The toughening efficiency of the ultrafine rubber particles was also reflected through the significant increase in the impact strength by fourfolds. Fractographs of the acrylate rubber-modified PLA verified plastic deformation and good dispersion of the rubber particles in the PLA. Microscopic observation revealed that the ultrafine acrylate rubber played an important role inducing numerous crazes as the mechanism for energy absorption. The introduction of the ultrafine acrylate rubber particles by only 0.5 wt% helped increasing the degree of crystallinity. (C) 2011 Elsevier B.V. All rights reserved.