Non-isothermal crystallization kinetics of organic montmorillonite/SiO₂ aerogel/PET composites

Abstract

Purpose

Crystallization kinetics is a key factor that controls the crystallization process of polymers and influences the crystallinity and morphology of polymers. This study aims to explore the effects of functional filler SiO₂ aerogel and co-modified filler organic montmorillonite (OMMT) on the crystallization process of polyester polyethylene terephthalate (PET). In this study, the nonisothermal crystallization kinetics of OMMT/SiO₂ aerogel/PET composites were studied by Jeziorny method.

Design/methodology/approach

The catalyst (Sb₂O₃), OMMT and SiO₂ aerogel were uniformly dispersed in ethylene glycol (EG). Then, the mixture and terephthalic acid (PTA) were put into a semicontinuous polyester synthesis reactor, and the SiO₂ aerogel/PET composites were prepared by esterification and polycondensation.

Findings

Non-isothermal kinetic results showed that the high cooling rate hindered the movement of the molecular chain of the composites and made the crystallization peak move toward the low-temperature direction. With the increase of crystallization temperature (T_c), the melt crystallization rate decreases, but the cold crystallization rate increases. The introduction of OMMT and SiO₂ aerogel condensation affected the nucleation and growth mode of crystals, lengthened the time with a relative crystallinity of 50% (t_1/2) and decreased the crystallization rate. OMMT improved the crystallinity and Avrami index of the composites.

Research limitations/implications

Effects of thermal insulation functional filler SiO₂ aerogel and co-modified filler OMMT on the crystallization process of PET were studied by non-isothermal crystallization kinetics, and the effects of SiO₂ aerogel and OMMT on the nucleation mechanism of PET were clarified, which provided a theoretical reference for the preparation and performance optimization of PET matrix composites.

Originality/value

In this study, the OMMT/SiO₂ aerogel/PET composites were prepared by in-situ polymerization, the crystallinity of PET matrix composites was improved, and the effects of OMMT and SiO₂ aerogel on the crystallization process of PET were clarified.

Citation

Gao, H., Xu, S., Yang, F., Zhang, Z., Wang, S., Jiang, X. and Dong, Y. (2024), "Non-isothermal crystallization kinetics of organic montmorillonite/SiO₂ aerogel/PET composites", Pigment & Resin Technology, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/PRT-06-2024-0065