Mechanism and kinetics of moisture-curing process of reactive hot melt polyurethane adhesive

• Published in: Chemical engineering journal advances Vol. 4; p. 100051
• Main Authors: Sun, Li, Zong, Zegang, Xue, Weilan, Zeng, Zuoxiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2020; Elsevier
• Subjects: Diffusion; HMPUR; Kinetic model; Mechanism; Moisture-curing; Kinetic model; HMPUR; Moisture-curing; Diffusion; Mechanism
• ISSN: 2666-8211; 2666-8211
• DOI: 10.1016/j.ceja.2020.100051

•A reactive hot melt polyurethane adhesive (HMPUR) sample was prepared.•The moisture curing kinetic data of the HMPUR film was measured.•A diffusion-reaction assumption was proposed to describe moisture-curing process.•Three kinetic models were established to correlate the kinetic data. Reactive hot melt polyurethane adhesive (HMPUR) was prepared by polycondensation of polyesters, pentaerythritol diacrylate (PEDA) and 4,4′-Methylene diphenyl diisocyanate (MDI). The moisture-curing kinetic experiments for HMPUR film with a thickness of 2.0 mm were carried out at various temperatures (283, 293, 303 and 313 K) and 85% relative humidity, with the mass changes dynamically monitored. A diffusion-reaction assumption was proposed to describe the mechanism of the moisture-curing process, and three kinetic models were established to correlate the moisture-curing kinetic data. The results showed that the model with the first-order reaction assumption is more reasonable. Based on the model, the time-dependent concentration profiles of water in HMPUR film, as well as the depth (x*) of water-diffusion, are predicted. Also, the reaction activation energy (Ek) and the diffusion activation energy (ED) were determined.