Elastomeric blends and method for their preparation

A resinous composition comprising:

• at least one thermoplastic polymer, and
• an impact modifying proportion of a copolymer composition prepared by:
• blending in a first step, under reactive conditions, at least one carbamate-functionalized addition polymer having the formula ##STR3## wherein:
• each R.sup.1 is independently hydrogen or C.sub.1-5 alkyl;
• each R.sup.2 is independently aryl or alkaryl of 1 to 20 carbon atoms;
• an ester group of 1 to 20 carbon atoms;
• alkoxy of 1 to 20 carbon atoms;
• acetoxy;
• or cyano;
• each R.sup.3 is independently a C.sub.1-10 hydrocarbyl moiety, provided that at least one R.sup.3 is alkyl;
• X.sup.2 is ##STR4## k is an integer in the range from 1 to about 1000;
• l is 0 or an integer from 1 to about 4000, and k and l may vary independently from unit to unit;
• m is an integer from 1 to about 100 and represents the number of carbamate-functionalized monomer and comonomer alternations when l is 1 or greater;
• and
• X.sup.1 is a chain terminating group;
• with an excess of at least one functionalized elastomer reactive therewith, to form an elastomeric preblend;
• and
• blending in a second step, under reactive conditions, said elastomeric preblend with a further amount of at least one functionalized addition polymer reactive with said functionalized elastomer;
• said copolymer composition comprising a continuous addition polymer phase having dispersed therein elastomer particles containing occluded addition polymer and being stabilized by copolymer formation between the elastomer particles and the addition polymer in the occluded and continuous phases.