In-situ synthesis of SiO2 aerogel/polyethylene terephthalate composite slices and their fibers

Purpose Polyethylene terephthalate (PET) as a fiber molding polymer is widely used in aerospace, electrical and electronic, clothing and other fields. The purpose of this study is to improve the thermal insulation performance of polyethylene terephthalate (PET), the SiO 2 aerogel/PET composites slices and fibers were prepared, and the effects of the SiO 2 aerogel on the morphology, structure, crystallization property and thermal conductivity of the SiO 2 aerogel/PET composites slices and their fibers were systematically investigated. Design/methodology/approach The mass ratio of purified terephthalic acid and ethylene glycol was selected as 1:1.5, which was premixed with Sb 2 O 3 and the corresponding mass of SiO 2 aerogel, and SiO 2 aerogel/PET composites were prepared by direct esterification and in-situ polymerization. The SiO 2 aerogel/PET composite fibers were prepared by melt-spinning method. Findings The results showed that the SiO 2 aerogel was uniformly dispersed in the PET matrix. The thermal insulation coefficient of PET was significantly reduced by the addition of SiO 2 aerogel, and the thermal conductivity of the 1.0 Wt.% SiO 2 aerogel/PET composites was reduced by 75.74 mW/(m · K) compared to the pure PET. The thermal conductivity of the 0.8 Wt.% SiO 2 aerogel/PET composite fiber was reduced by 46.06% compared to the pure PET fiber. The crystallinity and flame-retardant coefficient of the SiO 2 aerogel/PET composite fibers showed an increasing trend with the addition of SiO 2 aerogel. Research limitations/implications The SiO 2 aerogel/PET composite slices and their fibers have good thermal insulation properties and exhibit good potential for application in the field of thermal insulation, such as warm clothes. In today’s society where the energy crisis is becoming increasingly serious, improving the thermal insulation performance of PET to reduce energy loss will be of great significance to alleviate the energy crisis. Originality/value In this study, SiO 2 aerogel/PET composite slices and their fibers were prepared by an in situ polymerization process, which solved the problem of difficult dispersion of nanoparticles in the matrix and the thermal conductivity of PET significantly reduced.