One of the dirtiest and most demonized portions of the municipal waste stream may soon be diverted from landfills. Developing a recycling solution for used disposable diapers, a biological amalgam of complexity, has been a top priority of the global research and development team at TerraCycle Inc., a Trenton-based company whose mission is to create innovative solutions for waste streams. TerraCycle’s team of scientists, led by Ernie Simpson, global vice president of research and development, is about to put a clothespin on its formula that will render dirty diapers into a material suitable for plastic lumber, pallets and outdoor furniture.