Foaming with Polymer Microspheres in Rotational Molding: The Effect of Coupling Agent

The use of polymer microspheres for producing fine-cellular foams is a new development in rotational molding. In previous studies, some reduction in mechanical properties has been found due to the immiscibility between the polymer shell and the matrix polymer. Coupling agents can act as a molecular bridge at this interface and can also affect bubble growth by altering the rheological properties of the matrix polymer as well as the microsphere shell material. The influence of different coupling agents on the melt properties of several resins was investigated, as well as the effect of these coupling agents on the mechanical properties of foamed rotationally molded parts.