IWPDF2023

Effect of Prooxidants on LDPE and LDPE/Thermoplastic Starch Blends Properties

S. Djellali 1 , 2 , ∗ , A. Djenane 2 , S. Akhrib 2

1 Department of Chemistry, Faculty of Sciences, University Ferhat Abbas- Setif 1, 19000 Setif, Algeria 2 Laboratory of Physico-Chemistry of High Polymers, University Ferhat Abbas- Setif 1, 19000 Setif, Algeria

∗ souad.djellali@univ-setif.dz

Keywords: Prooxidants, Polyethylene degradation, Mechanical tests, Thermoplastic starch.

Low density polyethylene, while commonly used, contributes significantly to the exacerbation of ecological concerns owing to its slow environmental degradation and lack of biodegradability [1]. In order to address this pressing concern, the incorporation of prooxidants in small quantities can be a transformative solution. By introducing these substances, hydrophilic functional groups can be formed along the macromolecular chains, rendering them more vulnerable to microbial attack and degradation [2]. By adopting this approach, our research attempts to combine low-density polyethylene with stearate-based prooxidants to initiate the thermal degradation of the polymer backbone. Sub sequently, the resulting Ox-PE mixtures are blended with thermoplastic starch (TPS) to yield a novel material that claims improved biodegradability and superior performance characteristics. The prepared LDPE/prooxidant and Ox-LDPE/TPS blends are characterized by FTIR spec troscopy, contact angle and mechanical tests. The FTIR of Ox-LDPE shows that the metal ions Mn2+ can act as thermal catalysts while Fe3+ was not effective in accelerating thermal degradation. Contact angle results of Ox-LDPE indicate a lowering in the PE hydrophobicity while the tensile test revealed that Mn2+ is the most efficient prooxidant. This interpretation results from the largest performance loss observed in the PE-Mn mixture. Moreover, the analy sis of Ox-LDPE/TPS blends highlights the accumulation of carbonyl groups following the initial phase of thermo-oxidation, suggesting a rise in the degradation of the polymer chains. References [1] Portillo, F., Yashchuk, O., Hermida, É. (2016). Evaluation of the rate of abiotic and biotic degradation of oxo-degradable polyethylene. Polymer Testing, 53, 58-69. [2] Abdelmoez, W., Dahab, I., Ragab, E. M., Abdelsalam, O. A., & Mustafa, A. (2021). Bio-and oxo-degradable plastics: Insights on facts and challenges. Polymers for Advanced Technologies, 32(5), 1981-1996.

132