Bio-based polyurethane for road engineering applications: A comprehensive review

With the escalating global emphasis on environmental conservation and sustainable development, enhancing the service quality and durability of road surfaces and facilitating the green development of highways have commanded considerable attention. Bio-based polyurethane, on account of its remarkable physical and chemical properties, green, sustainable and renewable capacity, as well as its structural design capabilities, has drawn widespread attention and numerous studies have been carried out. It has gradually started to substitute traditional petroleum-based polyurethane materials in road engineering. Nevertheless, the application of bio-based polyurethane materials in road engineering remains in the exploratory phase. To stimulate the application research of bio-based polyurethane materials in road engineering and offer additional research directions, this paper reviews the research advancements of bio-based polyurethane materials and their applications in road engineering. The fundamental classification of bio-based polyurethane is introduced. The characteristics and challenges associated with various preparation methods for bio-based polyurethane are described. The influence of bio-based polyurethane on road engineering materials are analyzed. The evaluation indicators of bio-based polyurethane within the life cycle of road engineering are investigated. Finally, the development tendency towards in road engineering applications are forecasted. This paper provides a reference for the study of bio-based polyurethane materials in road engineering applications.