Impact of the chain extension of poly(ethylene terephthalate) with 1,3‐phenylene‐bis‐oxazoline and N,N′‐carbonylbiscaprolactam by reactive extrusion on its properties

Abstract

In this article, the material properties of chain extended poly(ethylene terephthalate) (PET) by application of the chain extenders, 1,3‐phenylene‐bis‐oxazoline (1,3‐PBO), N,N′‐carbonylbiscaprolactam (CBC), and combinations thereof are investigated aiming at an application during fiber production from postconsumer PET. The chain extension is performed in one step by a reactive extrusion process. The chain extenders are linearly linked to the COOH and/or OH terminal groups of PET. The influence of the chain extension on the properties of PET is analyzed by measurement of the inherent viscosity, size exclusion chromatography, and carboxyl end‐group titration. Furthermore, the impact of the chain extension on the thermal and rheological properties of PET is studied in detail by differential scanning calorimetry and rheology. The results demonstrate that chain extenders have impact on the properties of PET in dependence on their chemical composition and concentration. The improvement of the molecular weight of the obtained compounds is achieved in an effective and economical approach by the addition of small concentrations of chain extenders (0.2 wt% 1,3‐PBO or 0.3 wt% CBC) without significant negative impact on the properties of PET. POLYM. ENG. SCI., 59:284–294, 2019. © 2018 Society of Plastics Engineers

A Review on the Formulation and Rupture Properties of Polyethylene Terephthalate in a Mechanical Recycling Context

“…15,83,156 Byproducts can also be formed during reactions between the PET and the additives, which can modify the rheology and thermal stability. 148,149 The development of nonhazardous functionalized molecules capable of enhancing properties with a fixed morphology has been found to be difficult. Another possibility is a combination of several technologies.…”

Investigation of the Reaction Kinetics of Poly(butylene terephthalate) and Epoxide Chain Extender

“…[3,[16][17][18] Chain extenders are multifunctional additives that can react with the terminal functional groups of the polymers. For polyesters, many different systems of substances are already known and studied that can be used as chain modifiers, such as isocyanides, [14,19] phosphites, [20,21] pyromellitic acid dianhydride, [3,[22][23][24] epoxides, [2,18,[25][26][27][28][29] and others, [30,31] with varying degrees of efficiency. As summarized in a recently published review article, one of the most commonly used chain extenders both in industry and academia is Joncryl ADR4468 from BASF.…”

Diisocyanate‐based chain extension via Mg(II) catalyzed amide formation to high‐molecular‐weight poly(lactic acid)

“…22 In addition, CERs can be potentially applied to mechanical recycling or repair to restore the molecular weight, which decreases during the service life of HMW-PLA. 23 Difunctional compounds such as diisocyanates, 15-19 bisoxazolines, 16,24,25 diepoxides, 26 diacid chlorides, 27,28 acid anhydrides, 27 bislactams, 24 and carbodiimides 21 are commonly used as chain extenders for polyesters including PLA. These functional groups usually react with either the hydroxy or carboxylic acid groups of the PLA termini, whereas isocyanates can react with both hydroxy and carboxylic acid groups (Scheme 1).…”