Improvement of impact properties of dynamically cross-linked networks by using reactive impact modifiers

A method of preparing a pre-dynamic cross-linked polymer composition, comprising:

• reacting (a) a coupler component and (b) a chain component comprising a polyester having one or more reactive end groups;
• and
• adding one or more networking impact modifier additives comprising one or more groups reactive with the one or more reactive end groups of the chain component, under such conditions that the one or more networking impact modifier additives covalently bond to the one or more reactive end groups of the chain component,
• the reacting being performed in the presence of at least one catalyst that promotes formation of the pre-dynamic cross-linked composition, and
• the pre-dynamic cross-linked composition when subjected to a curing process (a) exhibits a plateau modulus of from about 0.01 MPa to about 1000 MPa when measured by dynamic mechanical analysis at a temperature above a melting temperature of the polyester of the pre-dynamic cross-linked composition and (b) exhibits a capability of relaxing internal residual stresses at a characteristic timescale of between 0.1 and 100,000 seconds above a glass transition temperature of the polyester, as measured by stress relaxation rheology measurement.