INFLUENCE OF SELF-HEALING IONOMER ON POLYMER WASTE MANAGEMENT: STRUCTURE AND PROPERTY CORRELATION

Abstract

Polymer pollution is increasing at alarming rate and the need for waste management must be taken seriously. Recycling and reuse of polymer wastes not only reduce land fill and ocean fills, it is also a major step towards environmental conservation and sustainability. The major plastic pollutants i.e. PET bottle and PE bags have been taken for consideration for recycling dual plastic waste. As these two plastic wastes are not compatible, poly (ethylene-co-methacrylic acid) copolymer has been used as compatibilizer to process these two plastic wastes. Effect of doses of poly (ethylene-co-methacrylic acid) copolymer as compatibilizer has been studied here. It has been observed that only 3 weight percentage of poly (ethylene-co-methacrylic acid) copolymer is sufficient to make 3:1 mass ratio of PET bottle and polyethylene bags compatible. Compatibility has been examined through mechanical testing, thermal and morphological analysis. After analyzing the property of recyclates, better mechanical and thermal property has been observed. Almost 500% of tensile strength has been improved by addition of 3 weight percentage of poly (ethylene-co-methacrylic acid) copolymer in 3:1 mass ratio blend of PET bottle and PE bags than that of pristine blend. Household plastic wastes like polyethylene terephthalate bottles, polyethylene bags, polyvinyl chloride sheets, and polypropylene decorative ribbons were recycled focusing on their difference in polarity by utilizing poly (ethylene- co- methacrylic acid) copolymer sodium ion to evaluate the efficiency of ionomer in recycling quaternary plastic waste. The composition of the blend is varied by altering the level of loading of a two-phase compatibilizer. The composition with 7 wt% loading of compatibilizer showed improved properties than the neat blend. Tensile strength and elongation at break (%) improvement of 117% and 485%, respectively reflected in the composition containing 7 wt% of ionomer as a compatibilizer on comparing with 0 wt% of ionomer, making them ideal composition. Comparative study on repeated processing up to three cycles and their compatibilization mechanism has been reported. Recycling of mixed waste, including plastic and rubber, by the blending process is one of the promising sustainable routes. In this work, the processing of crumb rubber with waste thermoplastic polypropylene is reported. The poly(ethylene-comethacrylic acid) copolymer sodium ion was introduced as a compatibilizer. The waste materials were processed by injection molding techniques into a recyclate of improved value-added plastic–rubber recyclate. There was an improvement of tensile strength and modulus of about 60 and 85%, respectively, by addition of 7 wt.% of ionomer as compatibilizer. Enhanced thermal stability was also observed as compared to that of neat blend. The change in morphological characteristics that influence the end properties was analyzed by field emission scanning electron microscope and atomic force microscope. Evaluation of compatibility of different phases and stress transfer tendency was studied using tensile fractured and molded samples. The changes in thermo-mechanical properties are correlated to morphological characteristics, and the efficacy of the compatibilization process was estimated. Quaternary thermoplastic waste collected along with crumb rubber was melt blended in the presence of polyethylene co methacrylic acid copolymer sodium ion in different proportions. Considering that the mixed recycling of thermoplastic and crumb rubber wastes increases non-compatibility, two-phased ionomer introducing ion-dipole interaction in the new polymer blend is preferred. The compatibilization effect was evaluated by analyzing the influence of ionomer on the morphological aspects of blends. The reduced dimension of dispersed phase after compatibilization and intermolecular interaction from the ionomer improved the interfacial adhesion and was visualized from FESEM and AFM. As a result, mechanical strength has improved to 150%, energy to rupture to 655%, and high thermal stability. Analyzing the various compositions of recycled mixed polymer waste, better performance was achieved with a 7wt% addition of ionomer, making it critical composition. The mixed recycling of quaternary thermoplastic waste and crumb rubber contribute to sustainability, waste management and reutilization of post-consumed materials.