Abstract: A carrier-free expandable filler insert for filling or sealing a hollow space or cavity is provided. The insert comprises a self-supporting continuous structure that may be produced by contour extrusion molding or injection molding a polymer matrix containing a polymer and/or polymer precursor and a latent blowing agent. The expandable filler insert is secured to the interior surface of a vehicle pillar, for example, using a fixing element that may be integral with the self-supporting continuous structure, the polymer matrix thereafter being activated and expanded by heating.

Abstract: A thermally expandable material comprising a first thermoplastic elastomer having a first glass transition temperature, a second thermoplastic elastomer having a second glass transition temperature, wherein the first and the second glass transition temperature differ by at least 10° C.; at least one thermoplastic polymer selected from the group consisting of polymers and copolymers with at least one polymerizable C?C double bond, optionally at least one tackifying resin, at least one latent chemical blowing agent in an amount effective to cause the expandable material to expand at least 50% in volume when heated.