Recycled Poly(Ethylene Terephthalate) from Waste Textiles with Improved Thermal and Rheological Properties by Chain Extension

Abstract

Annual production of textile fibers is continuing to rise and the substantial discharge of undegradable waste polyester fibers can cause serious environmental and even health problems. Thus, the recycling and reuse of recycled poly(ethylene terephthalate) from waste textiles (rPET-F) is highly desirable but still challenging. Here, five chain extenders with a different number of epoxy groups per molecules were used to blend with discarded PET fibers and improve its viscosity and quality loss in the recycling process. The molecule weight, thermal properties, rheological properties and macromolecular architecture of modified r-PET were investigated. It was found that all modified rPET-F samples show higher viscosities and better thermal properties. rPET-F modified by difunctional EXOP molecules show linear structure and improved rheological properties. rPET-F modified by polyfunctional commercial ADR and synthesized copolymers exhibit a long chain branched structure and better crystallization. This study reveals a deeper understanding of the chain extension and opens an avenue for the recycling of PET textiles.

Progress in recycling and reutilization of waste polyethylene terephthalate

“…Bottles contain fewer additives and pigments than textiles and can be easily sorted using automated Near-Infrared Reflectance Spectroscopy (NIRS) technology. Wu et al 44 compared the properties of recycled PET fibers, bottle flakes, and virgin PET pellets. The recycled PET fibers had lower molecular weights and inferior properties and contained more impurities.…”

Glycidol-Free Aliphatic Copolymers as Chain Extenders for Polylactic Acid and Their Cost and Carbon Emission Assessments

“…ADR has been commercialized although it is synthesized using glycidyl methacrylate, with glycidol being one of the components. The ester bonds in GMA (glycidyl methacrylate) show increased susceptibility to hydrolysis because of stronger electron pull from a nearby epoxy group as evident from 1 H NMR . In the event of such hydrolysis, glycidol, a known carcinogen, can be generated .…”

Preparation of functionalised heteropolyacid ionic liquids and their application in catalytic degradation of bottle-grade polyester

“…PET degradation methods mainly include physical methods [8][9][10][11][12][13] and chemical methods. [14][15][16][17][18][19][20] Physical methods are used to recycle waste polyester bottles by means of crushing and melting without changing the chemical structure, and only low value-added products can be obtained in this way due to reduced performance.…”