Non-limiting examples of such matrix polymers are (1) polyamides such as Nylon 6, Nylon 6/6, Nylon 12, polyaspartic acid, polyglutamic acid; (2) polyamines; (3) polyimides; (4) polyacrylics such as polyacrylamide, polyacrylonitrile, and esters of methacrylic acid and acrylic acid; (5) polycarbonates such as polybisphenol A carbonate, and polypropylene carbonate; (6) polydienes such as polybutadien