Study on the pyrolysis characteristics of styrene-grafted polypropylene cable insulation material

Abstract

Polypropylene (PP) has garnered significant attention as a cable insulation material due to its exceptional electrical performance and recyclability. Styrene-grafted polypropylene (PP-g) emerges as a promising alternative in this context. This study employs thermogravimetric-gas chromatography experiments and reactive molecular dynamics simulations to compare the pyrolysis process and decomposition products of pure PP and PP-g as cable insulation materials. Results indicate that while both materials produce similar pyrolysis products, PP-g exhibits greater resistance to decomposition than PP. The predominant hydrocarbons in the decomposition products include methane (CH4), ethylene (C2H4), propylene (C3H6), and ethane (C2H6). The relative proportion of hydrocarbons decreases with increasing temperature, with a shift toward increased C2H6 production. The ratio of C2H6 to (CH4 + C2H4) molecular weights in thermal decomposition products rises with temperature, suggesting enhanced stability. Graft modification alters the decomposition pathway, specifically increasing the generation of C2H6. This study lays a theoretical foundation for cable aging monitoring and life assessment.