Optimizing Electron-Beam Photothermal Pyrolysis Parameters for Enhanced Molecular Biodegradability of Polyvinyl Chloride Plastics

Abstract

Polyvinyl chloride (PVC), a synthetic plastic notable for harmful emissions during deterioration, has potential to be molecularly adjusted by photo-oxidative ultraviolet degradation. This research investigates the influence of electron beam irradiation and near-infrared photothermal treatment utilizing gold nanoparticles to establish the optimized molecular weight and beam time exposure for biodegradable PVC properties while maintaining a minimum tensile strength as measured through the ratio of peak tension force by cross sectional area. PVC powder samples with number-average molecular weights ranging from 20.0 to 90.0 kDa and varying exposure times of a 100 kGy electron beam from 80 to 115 ms are employed for the study. Outcomes from PVC irradiation reveal the optimal parameters for inducing biodegradability in samples: an e-beam exposure duration of 95 ms applied to PVC powder with a sample molecular weight of 20.0 kDa. Analysis of the ratio of number average molecular weight $M_n$ and weight average molecular weight $M_w$ demonstrates that shorter irradiation durations result in lower molecular weights and molecular weight is directly proportional to T_g and crystallinity. Future work aims to scale up the procedure to industrial applications and investigate the treatment's applicability to a variety of thermoplastics.