Recycling of polyethylene waste as reinforced composites with modified lignocellulosic materials from palm oil industry

Abstract Mechanical recycling of polymer films has always been a challenge due to factors such as the combination of different polymers in multilayer films, the cost of producing recycled polymer being similar to that of virgin material, contaminations or insufficient properties for use in original applications, and difficult for processing when compared to virgin polymers. Low-density polyethylene (LDPE) is the polymer most employed for films production, mainly in packaging that present a lifetime very short and quickly become waste. Thus, the reinforcement of low-density polyethylene with low-cost filler can generate composites with improved mechanical performance to application in durable products with a longer useful life. In present study, palm waste was used to preparation of natural fibers (NF), cellulose (CEL) and cellulose nanofibrils (CNF), which were incorporated to the low-density polyethylene waste by thermomechanical processing, generating different composites. Significant changes in mechanical properties were observed in the composites compared to the unfilled polymer, particularly in impact resistance. The incorporation of 1 wt% cellulose nanofibrils resulted in a 40% increase in impact resistance. Other properties such as conservation of appropriated level of tensile performance and coloration similar to natural wood favor the application of material in several products. The development of sustainable polymer composites based on post-consume polymer waste and agro-industrial waste from palm oil have showed as an interesting alternative for mitigating the environmental damages caused by these wastes and for generation of new sustainable materials, revealing the novelty of the study.