Effect of silver nanoparticles modified by depolymerized monomer from waste PET on the thermo-induced shape memory properties of PVA

Depolymerization of waste polyethylene terephthalate (PET) into monomers for high-value reuse serves as an effective recycling strategy. Polyvinyl alcohol (PVA) is an important water-soluble polymer, which can be improved by the addition of silver nanoparticles modified with depolymerized monomer terephthalic acid (rTPA) to further improve the shape memory performance of PVA. Silver nanoparticles are notably responsive to thermal changes due to their distinctive chemical and physical properties. Nonetheless, their tendency to aggregate and high surface energy present difficulties in achieving stable dispersions in aqueous environments. In this research, silver nitrate solution was reduced to prepare silver nanoparticles under the action of the reducing agent ascorbic acid. Modified silver nanoparticles p-rTPA@Ag were prepared by co-precipitation of the nanoparticles with rTPA. A mixture of PVA and p-rTPA@Ag was prepared to form a composite PVA/p-rTPA@Ag. Modified silver nanoparticles, p-rTPA@Ag, exhibited enhanced dispersion in aqueous solution. The elongation at break of the composite rose markedly from 169.8% to 315.3%, an increase of 86.7%. Additionally, the shape recovery rate improved from 53.51% to 83.86%, reflecting a 56.7% enhancement.Highlights Silver nanoparticles were modified by depolymerized terephthalic acid (rTPA) Monomer rTPA improves the compatibility between PVA and Ag nanoparticles p-rTPA@Ag enhances temperature sensitivity of PVA p-rTPA@Ag enhances thermo-induced shape memory properties of PVA