9560213 Bryant This Small Business Innovation Research (SBIR) Phase I project will investigate microencapsulation of phase change materials (PCMs) in a form stable enough to withstand the melt spinning process. If micro PCMs could be incorporated into melt-spun fibers, the resulting fabrics (polypropylene, nylon, polyester) would have greatly enlarged thermal storage capacities. Micro PCMs have been successfully incorporated into low temperature, solution-spun acrylic fibers and fabric samples, increasing their thermal storage tenfold. However, at melt spinning temperatures (higher than 200oC) micro PCMs particles lose their core material, which corrupts the melt spinning process. Before these materials can successfully be incorporated into melt spun fiber, capsules must be available with more stable wall structure. Phase I will use differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA) to establish the behavior of current micro PCMs at temperatures exceeding 200oC and to understand the mechanism of microcapsule failure. On this basis microcapsules will be produced with modified wall structures. Their stability at high temperature will be compared to that of existing microcapsules. The most promising concepts for thermal stability of micro-PCMs would be pursued in Phase II. As micro-PCMs that are stable at high melt-spinning temperatures are made, thermally enhanced materials can be fabricated and marketed from melt spun fibers for apparel and industrial insulation materials, where hot or cold thermal control is needed.
