Ternary reactive blends of nylon-6 matrix with dispersed rigid brittle polymer and elastomer

Except by elastomers, the toughness of nylon-6 (N-6) can be improved by the addition of rigid poly(styrene-co-maleic anhydride) (SMA). In this case, s trength and stiffness are also enhanced. Combination of SMA with maleated e thylene-propylene rubber or styrene-ethene/butene-styrene with a total cont ent below 15% gives a ternary blend having a toughness level close to elast omer toughening, whereas the strength and stiffness reached at least the Ny lon-6 values. An explanation is a synergistic combination of both elastomer and rigid polymer toughening mechanisms. An opposite effect on mechanical behavior was found with high contents of both additives. Except for worsene d strength and stiffness, in some cases, a higher elastomer content even di d not enhance the toughness. This effect can be explained by too fine phase structure found, causing the matrix ligament dimension to be below its min imum critical value. (C) 1999 John Wiley & Sons, Inc.