Manufacturing and characterization of natural zeolite-filled TPU composites: influence of loading ratio and calcination of zeolite

Abstract

The reinforcing efficiency of natural zeolite for thermoplastic polyurethane (TPU) is evaluated in terms of calcination and loading level. Calcination was applied to the zeolite powder before the compounding process. The surface area, chemical compositions, particle size distribution, and surface functionalities of pristine zeolite (Z) and calcined zeolite (C-Z) are confirmed via BET analysis, EDX, particle size analysis, and FTIR spectroscopy, respectively. The manufacturing of composites was conducted using melt-compounding and injection molding techniques. The addition of C-Z to TPU yields higher results compared to Z-filled TPU, as determined by mechanical test parameters. Highly loaded Z and C-Z containing composites resulted in a reduction in the mechanical performance of the composites. This lowering trend is confirmed by SEM micrographs, which showed agglomerates and a decrease in dispersion quality in the morphology of composites with 20 % and 30 % of Z particles. According to thermal analysis, the integration of Z and C-Z shifts the decomposition rate and degradation temperature of TPU to higher values. In other words, the incorporation of zeolite leads to an enhancement in the thermal stability of TPU. C-Z compounded composites exhibit higher performances compared to Z-filled composites.