07 Jul Isocyanate-Free, Room-Temperature Curing Polyurethanes for Structural Applications Back to Sci. Publications

ABSTRACT

This study presents the development and characterization of novel hybrid non-isocyanate polyurethanes (NIPUs) for structural adhesive applications. A one-pot synthesis method at room temperature was developed, combining polyfunctional cyclic carbonates, diethylenetriamine, and epoxy. Kinetic investigations revealed significant differences between bi- and tricyclic carbonates, with tricyclic variants demonstrating superior curing kinetics. The hybrid NIPUs exhibited remarkable lap-shear strengths of 14–16 MPa on untreated aluminum and planed beech wood after 12 hours of room-temperature curing. The absence of isocyanates offers health and safety advantages in various applications. The versatility of hybrid NIPUs was demonstrated through their broad adhesion spectrum and adaptable mechanical properties, positioning them as promising candidates for diverse industrial applications, including battery component encapsulation and multi-material laminates. While challenges remain, particularly in the availability of higher-functional cyclic carbonates, this research opens new avenues for high-performance adhesive systems.

KEYWORDS

polyurethanes, non-isocyanate polyurethanes, room-temperature curing, structural, metal adhesion

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