Architectural Sustainability and Efficiency of Enhanced Waterproof Coating from Utilization of Waterborne Poly (Siloxane-Imide-Urethane) Copolymers on Roof Surfaces

Abstract

According to Taiwan’s Ministry of the Interior, from 2017 to 2019, more than 12% of house-purchase disputes were due to water leakage caused by frequent tropical rains, which have long troubled engineers. The thermal stability resistance, water resistance, and ultraviolet resistance of existing polyurethane formulations have been limited by environmental aging. Thus, the lifespan of commercial PU-coated resins (typical PU) for the waterproofing of roof surfaces is merely two to three years. Accordingly, this study proposed the introduction of siloxane and imide groups to produce waterborne poly(urethane-siloxane-imide) (Si-imide-WPU) copolymers to improve the resistance of environmental aging in typical PU. The waterproof coating resin made of Si-imide-WPU copolymers was environmentally friendly, safe to use, and free of organic solvents. The results showed that the optimal Si-imide-WPU-2 sample in the study made improvements on the defects of polyurethane (PU) including its thermal properties, mechanical properties, environmental resistance, and lifespan which could be extended up to 5.4 years. Consequently, the studied Si-imide-WPU copolymers could reduce material waste while enhancing the sustainability and efficiency of the architecture.