Correlation of structure, rheological, thermal, mechanical, and optical properties in Low Density Polyethylene/Linear Low Density Polyethylene blends in the presence of recycled Low Density Polyethylene and Linear Low Density Polyethylene

Post-industrial low-density and linear low-density polyethylene blown films are mechanically recycled for reutilizing in the production of blown films for packaging applications. This process enables the production of films with lower cost and similar properties while preserving the environment and lowering the amount of waste material disposed of. The mechanical recycling process results in the production of recycled pellets. This process includes chopping, washing, drying, and reprocessing. Mixtures of these recycled materials and their virgin form with various concentrations are shaped into blown films with inherent 70 and 30 wt% loadings for low-density polyethylene and linear low-density polyethylene components, respectively. Fourier transform infrared spectroscopy results of the recycled material show no contamination or chemical reaction with other materials. Gel permeation chromatography is carried out on the virgin and recycled low-density polyethylene and linear low-density polyethylene, and the results indicate the occurrence of chain session and crosslinking during the recycling process. The decline in the thermal properties of the samples, seen from the differential scanning calorimetry results, indicates the presence of crosslinks. The effect of structural changes caused by the recycling process on the rheological properties is studied. The miscibility of the blend components is evaluated by Cole-Cole plots and then further proved by Han and Van Gurp-Palman curves. Mechanical properties display an upturn following the presence of the crosslinkes. A decline in the optical properties in the films caused by the refraction of light by the crosslink structure in the film bulk and on the surface is evident. Highlights * LDPE and LLDPE were recycled according to the circular economy approach * Blown films containing virgin and recycled LDPE and LLDPE were produced * Chain scission and crosslinking as a result of recycling were studied * Rheological, thermal, mechanical, and optical properties were studied KEYWORDS circular economy, crosslinking, mechanical properties, polyethylene, recycling, rheological properties
1 | INTRODUCTION The vast applicability of plastics due to their lightweight and ease of processing, along with other desirable features like high strength and sensible prices, has made them [...]