PRODUCTION OF PARTIALLY SILANE-CROSS-LINKED PP-COPOLYMER FOAMS

This contribution introduces a new method for the radically initiated silane-grafting of polypropylene (PP) copolymers adding a chemical foa ming agent, but keeping the degradation of the native chains to a mini mum. This results in foamable, with water crosslinkable materials whic h are no longer thermoplastic after the silane-bridges have developed since they have three-dimensional network structure that in contrary t o the native polymer gives a remarkably higher melt elasticity and sta bility. These modified structured solids recieve, compared with native PP, a much finer foam structure with closed cells and at the same tim e improved chemical, mechanical and thermal resistance.