Poly(ethylene terephthalate) (PET) is a polyester plastic, which is widely used, notably as a material for single-use plastic bottles. Its accumulation in the environment now poses a global pollution threat. A number of enzymes are active on PET providing new options for industrial biorecycling of PET materials. The enzyme activity is strongly affected by the degree of PET crystallinity (X), and the X is therefore a relevant factor to consider in enzyme catalyzed PET recycling. Here, we present a new experimental methodology, based on systematic thermal annealing for controlled preparation of PET disks having different X, to allow systematic quantitative evaluation of the efficiency of PET degrading enzymes at different degrees of PET substrate crystallinity. We discuss the theory of PET crystallinity and compare PET crystallinity data measured by differential scanning calorimetry and attenuated Fourier transform infrared spectroscopy.•This study introduces a simple method for controlling the crystallinity of PET samples via annealing in a heat block.•The present methodology is not limited to the analytical methods included in the methods details.
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http://dx.doi.org/10.1016/j.mex.2022.101815 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
South China University of Technology, South China Advanced Institute for Soft Matter Science and Technology, South China Advanced Institute for Soft Matter Science and Technology, 510640, Guangzhou, CHINA.
Nanoimprint lithography (NIL) has been broadly applied in the fabrication of nano-patterned polymer films for cost-efficiency and high through-put; however, the intrinsic tradeoff between mechanical strength and residual stress of polymer films significantly limits the NIL resolution while the harsh processing conditions limit its versatile applications to different substrates. Herein, 1 nm metal oxide cluster, phosphotungstic acid (PTA), is used to complexed with polyvinyl alcohol (PVA) for high-resolution NIL that can be operated at large-scale and mild conditions. The ultra-small size of PTA enables dense supramolecular interaction with PVA for the diminished crystallinity and accelerated chain dynamics that help relax the residual stress during film casting.
View Article and Find Full Text PDFTalanta
December 2024
Department of Chemistry, Lorestan University, Khoramabad, Iran.
A significant challenge in membrane production is the need for affordable materials that provide high efficiency for their designated applications. Employing recycled materials in membrane manufacturing is viewed as a promising solution to tackle this challenge. In this work, a superwettable polyethylene terephthalate membrane modified with cobalt zeolitic imidazolate framework (PET/Co ZIF) is prepared for the first time from recycled plastic mineral water bottles and used to extract polycyclic aromatic hydrocarbons (PAHs) from aqueous samples followed by high-performance liquid chromatography with UV detection (HPLC-UV).
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Polymer Engineering, Institute for Polymers and Composites (IPC), Campus de Azurém, University of Minho, 4804-533 Guimarães, Portugal.
This study investigated the optimal combination of compatibilizers and stabilizers to enhance the value of marine environment plastic (MEP). The composition of the plastics was analysed, and a simulated recycled plastic blend (sMEP) was prepared based on a simplified composition of actual MEP. Different concentrations of three commercial compatibilizers (C1, C2 and C3) were tested to improve tensile strength.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan.
We investigated the crystallization kinetics and morphology evolution of miscible crystalline/crystalline blends of poly(trimethylene terephthalate) (PTT) and poly(ethylene terephthalate) (PET) during isothermal melt crystallization. The integrated light-scattering intensity and the spherulite size increased gradually and then steeply as crystallization progressed in 70/30 PTT/PET at 215 °C, indicating the two-step crystallization behavior. The compact PET spherulite grew in the first step, and the dendritic PTT spherulite grew in the second step, forming the double spherulite consisting of a PET component in the inner region and a PTT one in the outer region.
View Article and Find Full Text PDFJ Contam Hydrol
December 2024
Department of Chemistry, Faculty of Science, Universidad de Chile, Santiago, RM, Chile.
This study investigated the adsorption of 4-Nonylphenol (4-NP) on aged microplastics (MPs) composed of polyethylene terephthalate (PET) and poly(butylene-adipate-co-terephthalate)/polylactic acid (PBAT/PLA). Morphological analysis revealed wear, wrinkles, and increased surface roughness in both aged MPs, with X-ray diffraction showing slight increases in crystallinity. Infrared spectroscopy showed an increase in the carbonyl index from 2.
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