The synthesis and curing kinetics study of a new fluorinated polyurethane with fluorinated side chains attached to soft blocks

Abstract

Fluorinated polyurethane (FPU) with fluorine in the side chain was obtained using fluorinated polyether glycol (FPO) with fluorinated side chains and 4,4′-diphenyl methane diisocyanate (MDI). The direct visual inspection of microstructures by SEM revealed that the separation degree of soft and hard segments decreased with the introduction of fluorinated groups into polyurethane soft segments, leading to a decrease in the crystallinity of FPU. The glass transition temperatures (T_g) measured by DMA indicated that the optimal working temperature window of FPU separating soft and hard glass transitions became narrow. And the mechanical properties and surface properties of the FPU were also measured. Curing kinetics of FPU was studied using a rotational rheometer, and the activation energy of FPU was obtained. The relationship between the curing temperature and the mobility of fluorinated groups was characterized by XPS. The result showed that F content in the FPU surface decreased with increasing curing temperature.