Scratch Recovery of an Urethane-based Network

摘要

Thermosetting urethanes are resins based on the reaction product of a polyisocyanate and a hydroxyl-containing chemical, such as a polyether polyol, an acrylic polyol, or a polyester polyol. The molecular weight and functionality, as well as the isocyanate/hydroxyl ratio of the raw materials, allows the design of thermosetting urethane systems that range in properties from soft (rubber-like) to hard (glassy) networks, used in a wide variety of applications (foams, rubbers, adhesives, paints etc.). The present study concerns the influence of temperature on the molecular mobility of a hard polyurethane network. First, as solvent evaporation (or film densification) and chemical reaction are decisive phenomena in the film formation, namely in the film structure and properties, they are separately studied to characterize the final polymer network. These phenomena are well described and their interdependence has been the subject of many studies.