Photodegradation of low‐density polyethylene with prooxidant and photocatalyst

Abstract

Low‐density polyethylene (LDPE) composite films with trisilver phosphate (Ag3PO4) and cadmium selenide (CdSe) particles as photocatalysts and manganese stearate as prooxidant were prepared. The film samples were irradiated under UV and visible light and their photodegradation were evaluated using Fourier‐transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. The carbonyl index of the photocatalyst containing samples was very higher than the pure irradiated LDPE and even prooxidant containing film. The morphologies of the irradiated composite films were completely changed and had many cavities and cracks. The thermal stability of the composites was very lower than the pure polyethylene. However the crystallinity of the LDPE films with photocatalysts was enhanced contrarily the LDPE film with manganese stearate. Generally the results showed that the combination of the prooxidant with photocatalyst have synergistic effect on the photodegradation of the LDPE and can be used to accelerate the degradation of the polyethylene films.

Influence of the nature of pro-oxidants on the photooxidation of polyethylene blown films

“…On the other hand, the PE_ONM film, with higher reduction of , higher increase in COi and Vi, shows extreme brittleness, clear in micrographic observation after 144 h of exposure. In another work [ 22 ], evaluating the photodegradation of PE_ONM with pro-oxidants and photocatalysts, morphological changes compatible with those obtained in this study were found, with changes as clearer the higher the degradation rate observed for the polymer.…”

“…Processing PE with pro-oxidant additives has been an option to favor the abiotic degradation of macromolecules, by photooxidation and thermooxidation, leading to the production of lower molar mass oxygenated fragments. In a second stage of the degradation process, these fragments are assimilated by microorganisms such as fungi, bacteria and algae, constituting the biotic degradation [ 4 , 14 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. When processed with such additives, PE is called oxo-biodegradable.…”

“…However, it is necessary that these fragments have a sufficiently small molar mass and contain adequate oxygenated functional groups to be biodegraded [ 16 , 18 , 26 , 27 ]. Pro-oxidants, also known as pro-degradants, are generally organic metal salts [ 22 , 28 , 29 , 30 ], mainly stearates of Co, Mn and Fe [ 8 , 24 , 25 , 31 , 32 , 33 ].…”

The Effect of Poly (Ethylene glycol) Emulation on the Degradation of PLA/Starch Composites

“…Optical-oxidative degradation of polymer samples is usually accompanied by the appearance of unsaturated bonds and various carbonyl groups by which the progression of degradation increases [ 70 ]. Two major observations—the formation of C=O (2000–1500 cm −1 ) and O-H groups in (4000–3000 cm −1 ) can also be found in the FTIR spectrum of polyolefin and other polymers [ 71 ].…”

Progressing Plastics Circularity: A Review of Mechano-Biocatalytic Approaches for Waste Plastic (Re)valorization

“…An increase in the crystallinity and carbonyl index was also observed after exposure of LDPE films to UV irradiations ( Gharehdashli et al, 2020 ). Ranjan et al indicated that the photodegradation of LDPE is faster in the air than its counterparts (double distilled water, two salt solutions with variable ionic strengths), under UV irradiation for 90 days.…”