Crystallinity of Recycled PET Fibers from Chemical and Mechanical Reprocessing
This work investigated the effect of isophthalate (iso) content in poly(ethylene terephthalate) (PET) materials on its degree of crystallinity (χ%) and mechanical properties. Melt blends were prepared from virgin (0 iso-wt.%) and bottle-grade (1.7 iso-wt.%) PET and subsequently spun into fibers. The mechanical and crystallinity properties were determined using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and uniaxial tensile testing. The crystallinity results determined from DSC and XRD quantified the relationship between iso-content and χ% in the materials. It was found that melt-mixing of different isophthalate grades had a lesser effect on melting temperature (Tm) and χ% than chemically recycled random copolymers of terephthalate and isophthalate. It was further shown that random copolymers of <0.25 iso-wt.% had comparable crystallinity to the virgin high-modulus low-shrink (HMLS) materials.ABSTRACT
Preparation process of PET fibers with different amounts of isophthalate via melt blending.
Melting temperature and crystallinity of blends and random copolymers.
The Young's modulus of annealed PET fibers prepared from melt blending.
Contributor Notes
School of Polymer Science and Polymer Engineering, The University of Akron, Goodyear Polymer Center, The University of Akron, Akron, OH 44325-3909, USA
Corresponding authors. Email: janas@uakron.edu, kac58@uakron.edu, eagan@uakron.edu