Improving the properties of recycled PET/PEN blends by using different chain extenders

Abstract

<jats:title>Abstract</jats:title> <jats:p>The main aim of this study was to improve the mechanical properties of the recycled poly(ethylene terephthalate)/poly(ethylene 2,6-naphthalate) (r-PET/PEN) blends by enhancing the miscibility between PET and PEN with the usage of chain extenders. This idea was novel for the recycled PET-based r-PET/PEN blends, as investigation of the effects of the chain extender usage on the properties of r-PET/PEN blends has not been studied in the literature, according to our knowledge. 1,4-Phenylene-bis-oxazoline (PBO), 1,4-phenylene-di-isocyanate (PDI), and triphenyl phosphite (TPP) were selected as chain extenders. The maximum tensile strength value was observed for the 1.0PDI sample. Moreover, PDI-based blends exhibited better Izod impact strength when compared with all other samples. The miscibility and degree of crystallinity values of all blends were discussed by means of thermal analysis. <jats:sup>1</jats:sup>H-nuclear magnetic resonance (<jats:sup>1</jats:sup>H-NMR) analysis was carried out to determine transesterification reaction levels. According to <jats:sup>1</jats:sup>H-NMR results, the increase in the level of transesterification was around 40% with the usage of PDI. The optimum loading level for selected chain extenders was determined as 1 wt.%, and PDI-based blends exhibited better properties when compared with those of the blends based on PBO and TPP at this loading level.</jats:p>

Effect of the Trifunctional Chain Extender on Intrinsic Viscosity, Crystallization Behavior, and Mechanical Properties of Poly(Ethylene Terephthalate)

“…It was found that compared to diepoxide, the addition of diisocyanate led to an increase in viscosity of PET. Can et al 33 investigated the effect of three different chain extenders including 1,4-phenylene-bis-oxazoline (PBO), 1,4-phenylene-diisocyanate (PDI), and triphenyl phosphite (TPP) on the mechanical property of the PET/PEN blend. It was found that the tensile strength could reach the optimum value after a certain amount of isocyanate was added.…”

Ultraviolet‐induced chain extension of poly(ethylene terephthalate) based on radical reaction with the aid of trimethylolpropane triacrylate and glycidyl methacrylate during extrusion

“…In the reactive extrusion process, a di‐ or multi‐functional low molecular weight compound reacts with carboxyl/hydroxyl end groups of PET to rejoin the molecular chain, resulting in increasing molar mass of the polymer and producing long‐chain branched macromolecules . Many chain extenders with different types of reactive groups have been reported to modify PET, such as oxazoline, isocyanates, organic phosphites and many kinds of epoxy‐based and anhydride‐based compounds . Among them, epoxy‐based and anhydride‐based compounds are commonly used.…”