Upcycling Discarded\nPolyethylene Terephthalate Plastic\ninto Highly Valuable Flexible Materials with Good Tensile Strength,\nWeather, and Corrosion Resistance via Molecular Structure Reconstruction

The chemical conversion of discarded\npoly(ethylene terephthalate)\n(dPET) into functional materials presents a promising approach to\nwaste disposal. However, the loss of flexibility and tensile strength\nsignificantly limits the practical application of these fabricated\nmaterials. This work aims to develop a simple and effective approach\nto convert dPET into functional materials with flexible properties\nthrough molecular structure reconstruction. Molecular structuresC<sub>10</sub>H<sub>11</sub>ClO<sub>3</sub>, (C<sub>7</sub>H<sub>4</sub>O<sub>2</sub>)<sub><i>n</i></sub>, and C<sub>15</sub>H<sub>14</sub>O<sub>3</sub>were formed through the introduction\nof styrene butadiene styrene block polymer to react with dPET. These\nthree products were embedded into a viscous fluid in rodlike or sheet-like\nshapes, and homogeneous and stable cross-linked structures were formed\nby physical and chemical bonds rather than a simple physical mixture,\nwhich is responsible for the good tensile strength, corrosion resistance,\nand weather resistance properties of the flexible material. The resulting\nflexible material had a tensile strength of up to 4.2 MPa. Even after\n50 cycles of stretching at 80% elongation without a dwell time, the\nsample retained its resilience. The material also exhibited good corrosion\nand weather resistance, with no deformation or dissolution observed\neven after 30 h of exposure to harsh environments, including strong\nacids, alkalis, and salt solutions. When exposed to simulated sunlight\nfor 6 h, the sample exhibited a strong resistance in the 200–340\nnm range. Overall, the successful fabrication of dPET into flexible\nmaterials presents a simple and effective approach to the high-value\ndisposal of waste plastic. The resulting samples show potential applications\nin various areas such as soft joints, shock absorbers, and pipe shock\nabsorbers.