Structural characterization of LDPE films to analyse the impact of heavy metals and effect of UV pre-treatment on polymer degradation

Abstract

Low Density Polyethylene (LDPE) films were selected possessing 50 μm, 75 μm, 90 μm and 100 μm thickness and 0.913 g/cm3 density. Physico-chemical and mechanical properties were analysed for testing inherent strength of the material. It was noted that 90 μm films possess low tensile strength with 14.491 MPa and showed highest value for Young’s Modulus with 176.213 MPa. Apart from these properties, other substantial parameters, such as Total Solids (TS), Moisture Content (MC), Total Organic Carbon (TOC) Content, Carbon, Hydrogen, Nitrogen, Sulphur (CHNS) content and Heavy metal content were also determined for observing the behavioural responses and structural configuration of the material. Films were then exposed to ultraviolet (UV) radiations for identifying photo-oxidative potential to enhance the rate of degradation of LDPE. To assess structural and morphological changes, Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX/EDS) analysis were performed. Characteristic functional groups identified by FTIR where H–CO, –CO and -C-O stretches were in the band range of 2700–2664, 1780–1665, 1260-1035 cm−1. Significant changes were observed after applied pre-treatment when films were irradiated under UV source in designed UV chamber. As polymer degradation is one of the emerging fields, current paper emphasized the role of primary characterization and necessity of polymer pre-treatment in the field of LDPE degradation.