Butyralization of poly(vinyl alcohol) under supercritical carbon dioxide for a humidity-resistant adhesive to glass substrates

Abstract

Poly(vinyl butyral) (PVB) was widely accepted as an adhesives for glass substrates of the window of the automobiles. In this work, we suggested and performed butyralization of poly(vinyl alcohol) (PVA) under supercritical carbon dioxide (sc-CO2) and investigated on the structure and mechanical properties of the obtained PVB as well as adhesion properties under various condition, comparing with the other PVBs prepared in the solution and swollen states. The conversion ratio of butyralization under sc-CO2 was larger than that in the swollen state and lower than in the solution state, which was sufficient for the material performance as the adhesive for glass substrates. The Young's modulus and tensile strength of the PVB under sc-CO2 were higher than those of the other PVBs. The mechanical properties of the PVB prepared under sc-CO2 have no correlation to the modification ratios because sc-CO2 penetrated into the amorphous region of PVA and modified its hydroxyl groups preferentially. Furthermore, the adhesive strengths of all the obtained PVB were increased and, under high humidity atmosphere, the adhesive strength of the PVB prepared under sc-CO2 was largest. The humid-resistant performance of the PVB adhesive prepared under sc-CO2 was proved.

Development of a D2O/H2O vapor generator for contrast-variation neutron scattering

“…The study of moisture absorption in polymeric films has received significant attention across various industrial applications, including polyelectrolyte membranes for fuel cells, coatings, sensors and adhesives (Jiao et al, 2021;Huang et al, 2021;Najeeb et al, 2018;Park et al, 2018;Pletincx et al, 2017;Matsumoto et al, 2020). Additionally, a recent report detailed structural changes in nanocellulose films at the nanoscale that could be attributed to humidity variations (Brett et al, 2019).…”