Effect of Cellulose-Based Bioplastics on Current LDPE Recycling

Abstract

The increased use of bioplastics in the market has led to their presence in municipal solid waste streams alongside traditional fossil-based polymers, particularly low-density polyethylene (LDPE), which bioplastics often end up mixed with. This study aimed to assess the impact of cellulose acetate plasticized with triacetin (CAT) on the mechanical recycling of LDPE. LDPE–CAT blends with varying CAT content (0%, 1%, 5%, 7.5%, and 10% by weight) were prepared by melt extrusion and analyzed using scanning electron microscopy, Fourier-transform infrared spectroscopy, thermal analysis (thermogravimetric and differential scanning calorimetry), dynamic rheological measurements, and tensile tests. The results indicate that the presence of CAT does not significantly affect the chemical, thermal, and rheological properties of LDPE, and the addition of CAT at different levels does not promote LDPE degradation under typical processing conditions. However, the addition of CAT negatively impacts the processability and mechanical behavior of LDPE, resulting in the reduced quality of the recycled material. Thus, the presence of cellulose-based bioplastics in LDPE recycling streams should be avoided, and a specific sorting stream for bioplastics should be established.

Biotechnological Solutions for Recycling Synthetic Fibers

“…Bioaugmentation involves the introduction of specific microorganisms into the environment, while biostimulation aims to increase the activity of existing microorganisms by providing nutrients or other growth-promoting factors. These approaches aim to accelerate the degradation process and increase the efficiency of fiber degradation [26][27][28]. Wei and Zimmermann focused on microbial biocatalysts involved in the degradation of the synthetic plastics polyethylene, polystyrene, polyurethane, and polyethylene terephthalate (PET) [29].…”

Production of Biodegradable Polymeric Composites with the Addition of Waste

“…The pollution generated by plastic and its impacts on the environment have attracted global attention from researchers, companies, governments and the general public [ 1 , 2 ]. Plastics produced from petroleum resources [ 3 ], which are only 110 years old [ 4 ], present a great threat to the environment because their demand has been growing for decades due to the ease of molding and transforming them into various products of daily use.…”

“…In this context, research has been directed towards investigating the production of biocomposites with natural reinforcing fillers [ 9 ], also known as bioplastics, which may be a good option to replace conventional plastics [ 2 , 10 ]. Currently, the production of bioplastics is about 1% of the total production of conventional plastic [ 2 ].…”

“…In this context, research has been directed towards investigating the production of biocomposites with natural reinforcing fillers [ 9 ], also known as bioplastics, which may be a good option to replace conventional plastics [ 2 , 10 ]. Currently, the production of bioplastics is about 1% of the total production of conventional plastic [ 2 ]. Bioplastics are produced using biodegradable or compostable polymers, which are derived from natural sources or simply synthesized from substrates of natural origin [ 9 ], such as starch [ 2 ], natural oils, protein and cellulose [ 10 ].…”

“…Currently, the production of bioplastics is about 1% of the total production of conventional plastic [ 2 ]. Bioplastics are produced using biodegradable or compostable polymers, which are derived from natural sources or simply synthesized from substrates of natural origin [ 9 ], such as starch [ 2 ], natural oils, protein and cellulose [ 10 ]. Starch is a good raw material for the production of polymeric matrices due to its biodegradability and low cost, being easily processed in the presence of a plasticizer, in addition to having polar groups that interact with the hydroxyls of lignocellulosic fibers, thus resulting in a material with mechanical strength, in addition to its high amylose content favoring film formation [ 3 , 11 , 12 ].…”