Self-Healing and Mechanical Properties of Thermoplastic Polyurethane/Eugenol-Based Phenoxy Resin Blends via Exchange Reactions.

Jing-Yu Liang,Soo-Hyoung Lee,Se-Ra Shin,Dai-Soo Lee

doi:10.3390/polym12051011

Abstract

The possibility of exchange reactions and thermal self-healing in blends of thermoplastic polyurethane (TPU) and phenoxy resin was investigated herein. The analyses were based on characterization obtained via differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), and tensile test. A new phenoxy resin was synthesized from eugenol, and blends with different types of TPU were prepared to investigate the exchange reaction, thermal self-healing, and mechanical properties. The influence of phenoxy resin content on the mechanical behavior and healing efficiency was studied. Improvement of storage modulus owing to the increase of phenoxy resin content was observed. Results suggest that the exchange reaction between phenoxy- and ester-type TPU occurred during thermal treatment. However, little exchange occurred between phenoxy resin and ether-type TPU. Specifically, only ester-type TPU exhibited a significant exchange reaction in the phenoxy resin blend. Furthermore, in the presence of a catalyst (e.g., zinc acetate), the exchange reaction readily occurred, and the healing efficiency improved by the addition of the catalyst and increase in the phenoxy content.

Highlights

Polymer blends have received considerable attention from both the industrial and scientific communities because they are economical materials that can be used to create new compounds in comparison with copolymers prepared from polymerizations [1,2,3]
The chemical structure of Eugenol epoxy (EE) was confirmed by the appearance of new signals (a’), (c, a), (b) at 2.53, 2.79, and 3.12 ppm, and the disappearance of the signals of (b1) and (a1, a1’) at 6.1 and 5.1 ppm, respectively, which are assigned to the protons of allyl groups
The self-healing and exchange reactions in the blends of thermoplastic polyurethane (TPU) and phenoxy resin were investigated in this study

Summary

Introduction

Polymer blends have received considerable attention from both the industrial and scientific communities because they are economical materials that can be used to create new compounds in comparison with copolymers prepared from polymerizations [1,2,3]. The miscibility of different polymers for the preparation of blends has been extensively studied. Many polymer blends are immiscible and require a compatibilization process to improve the performances of blends. Reactive polymer blends based on the functional groups such as carboxylic acid, amine, and hydroxyl groups were studied for the efficient compatibilizations of immiscible polymers [4,5,6]. Phenoxy resin is an amorphous thermoplastic, which has been extensively used in many fields such as in adhesives, coatings, and engineering plastics. The hydroxyl group of phenoxy resin is an active group and can react with proton-accepting functional groups in the polymers

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Results

Conclusion