acid alkali antioxidant applied spectroscopy biodegradation black ice carbonyl celsius chemically assisted degradation of polymers chlorine crutch environmental stress cracking environmental stress fracture extrusion forensic engineering forensic materials engineering forensic polymer engineering hard water heat hydrogen chloride hydrolysis lead-acid battery light molecule nbr natural rubber nylon oxygen ozone ozone cracking pollution polybutylene polycarbonate polyethylene polyethylene terephthalate polymer polymer engineering polypropylene polystyrene polyvinyl chloride recycling stress corrosion cracking structure determination styrene-butadiene synthetic biodegradable polymer tensile strength thermal degradation of polymers tire uv degradation vulcanization weather testing of polymers