Poly(lactic acid)/halloysite nanotubes nanocomposites: Structure, thermal, and mechanical properties as a function of halloysite treatment

Abstract

Abstract Poly(lactic acid) (PLA)/halloysite nanotubes (HNT) nanocomposites were prepared by melt extrusion using a masterbatch dilution process. Effect of addition of both unmodified halloysites (HNT) and quaternary ammonium salt treated halloysites (m‐HNT) was investigated at different nanofiller contents. A homogeneous distribution/dispersion of halloysites in the PLA matrix is obtained for both unmodified and modified nanotubes within the studied composition range. The nucleating effect of halloysites, resulting in a limited increase of degree of crystallinity, is more pronounced in the case of m‐HNT. Besides, the rigidity, tensile, flexural, and impact resistances of PLA significantly increase on addition of halloysites, the property improvement being higher for m‐HNT than for HNT. Interestingly, there is no significant embrittlement (almost constant elongation at break). Based on micromechanical models, this superior reinforcement efficiency of m‐HNT was ascribed to the better interfacial compatibility induced by the modification of the nanotube surface. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013