Physically-ameliorated styrene polymer/thermoplastic elastomer polyblends

Abstract

Several important features and characteristics, particularly and pronouncedly environmental stress crack resistance (i.e., 'ESCR') as well as other desirable physical properties of blends or intimate admixtures, known as 'polyblends' and usually made by melt-blending, of various styrene polymers (i.e., 'SP's'), notably homopolystyrene (i.e., 'PS'), and thermoplastic elastomers (i.e., 'TE's') are significantly and in emphasized measure enhanced by thorough incorporation in (and simultaneous or subsequent heat action-initiating and crosslink-effecting of) the SP/TE polyblend in low level concentration(s) of a thermally-activatable, organic peroxide in combination with any one (or even a mixture) of an optimizing cross-linking supplement provided in effectively reactive amounts of, for illustration, either a styrene (or the like alkenyl aromatic) monomer or a reagent that is reactive towards alkenes (such as certain dithiols, amino-derivatives, etc.) or certain decomposable-type reagents (such as hexachlorothene). Besides noteworthy improvement in ESCR, the tensile strength (including tensile yield--i.e., 'T.sub.y ' and tensile rupture--i.e., 'T.sub.r '), elongation (i.e., '% Elong.') and practical toughness (as measured by Gardner Impact Strength values) are among the significant physical properties thus ameliorated in the SP/TE polyblends.