Plasma-Induced Degradation of Polypropene Plastics in Natural Volatile Constituents of Ledum palustre Herb

Polypropene (PP) plastics can be effectively degraded by natural volatile constituents from Ledum palustre catalyzed by atmospheric air dielectric barrier (DBD) plasma. The electron spin resonance (ESR) result indicates that the volatile constituents produce radicals in aerobic condition energized by power sources such as light, UV, plasma and so on. The degradation is a novel chemically oxidative way and it is initiated by a series of radical reactions. Lots of active and oxidative species, radicals, products and high energy electromagnetic field in plasma aggravate the degradation process. The results about PP maximum tensile strength (σbmax) confirm this conclusion. PP plastic heavily loses its extensibility, mechanical integrity and strength in a short time after suffering a synergetic treatment of the herb extract and air DBD plasma with no toxic residues left. The components of herb extract keep almost unchanged and may be reused. This study offers a new approach to manage and recycle typical plastics.