Recyclable elastomeric vitrimer fabricated by reactive blending of maleated polyolefin elastomer with glycidyl POSS

Abstract

New types of chemically crosslinked polymers possessing reprocessability like thermoplastics, which are called vitrimers, are receiving great attentions. In this thesis, elastomeric polyethylene vitrimer was prepared by dynamic crosslinking commercially available maleated POE (mPOE) using polyhedral oligomeric silsesquioxane having glycidyl group (G-POSS) as a crosslinker in the presence of small amount of zinc acetlyacetonate (Zn(acac)2) as a catalyst via melt mixing method. Crosslinked network M. S thesis submitted by Hyeok Jun Ahn And directed by Prof. Young-Wook Chang Dept. of Master. Chem. Eng The graduate School Hanyang University containing β-hydroxy ester bonds was formed from the reaction between maleic anhydride group of mPOE and glycidyl groups of G-POSS during mixing, which was confirmed by FT-IR, gel content measurement and dynamic mechanical analysis. Recyclability, thermal, mechanical, and rheological properties examined by tensile test, TGA, and dynamic rheometer revealed that the as-prepared PE vitrimer showed greatly enhanced mechanical properties and thermal stability compared to neat POE along with good melt-processability and recyclability when POSS content is 1.0 phr. Such semi-crystalline PE vitrimer and its nanocomposite with a small amount of grapheme oxide (GO) exhibit thermo- and NIR-responsive shape memory behavior with tunable permanent shape reconfigurability. Preparation of PE vitrimers with triple-shape memory behavior was also reported here. These novel recyclable PE vitrimers can contribute to reduction in polymer wastes by replacing conventional non-recyclalbe crosslinked PEs in various applications.