Recycling waste polyethylene film for amphoteric superabsorbent resin synthesis

- A novel and low-cost amphoteric SAR from waste polyethylene film was prepared.
- The formation mechanism and structure of the prepared amphoteric SAR were clarified.
- The new material has highly practical value for its superior properties.
- A novel, moderate and convenient process for waste plastic recycling was provided.

Amphoteric superabsorbent resin (SAR) is excellent in both cation and anion adsorption. In the present study, typical waste polyethylene film was employed to develop a novel amphoteric SAR through polymerization with acrylic acid (AA) and dimethyl diallyl ammonium chloride (DMDAAC). The maximum water absorbing capacities of the obtained amphoteric SARs for distilled water and rainwater reached 286.3 and 213.5 g/g, respectively. A determination of the structure and morphology of the amphoteric SAR confirmed that monomers were successfully grafted onto the plastic film. The water absorbing capacity of SAR was greatly affected by the monomer to waste polyethylene ratio, the amount of initiator and cross-linker, the neutralization degree of acrylic acid and external solution. Meanwhile, the swelling kinetic, pH sensitivity, water retention and reswelling ability of the prepared polymer were also systematically investigated. This study provides a novel process for value-added recycling of waste polyethylene film.

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