Composite article and related methods

A composite article, comprising:

• a fastener comprising:
• an elongated body presenting a surface;
• a head joined with the elongated body and
• a thermally expandable composition disposed at least partially circumferentially about the elongated body, the thermally expandable composition comprising:
• (a) from about 45 to about 65 percent by weight of a copolymer of ethylene and methacrylic acid and an acid-modified ethylene acrylate resin;
• (b) from about 2 to about 15 percent by weight of a thermoplastic resin;
• (c) from about 1 to about 6 percent by weight of a curing agent comprising peroxyester for cross-linking the (a) polyolefin resin;
• (d) from about 30 to about 35 percent by weight of filler;
• (e) from about 1 to about 10 percent by weight of a chemical blowing agent comprising 4,4′-oxybis(benzensulfonyl hydrazide), which is activated at activation temperature;
• (f) a processing oil;
• and
• (g) m-phenylenedimaleimide accelerator;
• each based on the total weight of the thermally expandable composition.