LAUSR

Toughening of polyamide-6 (PA6) by elastomers without sacrificing the modulus of blends has always been a challenge. In this study, PA6 was modified by poly(styrene-alt-maleic acid)-block-polystyrene-block-poly(n-butyl acrylate)-block-polystyrene tetrablock copolymer (BCP) elastomer. The introduced acid groups in BCP resulted in the size of BCP inclusions down to nanometers in polyamide matrix. 10 wt % of BCP modified PA6 blends achieved five times increase in notched impact strength with almost no loss in modulus. Microscopic observations suggested the cavitation of elastomer particles and shear yielding of PA6 matrix to be the major toughening mechanism. This research provides a strategy to toughen polyamides by block copolymers at very low rubber content. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44849.