UV-curable polyurethane acrylate resin containing multiple active terminal groups for enhanced mechanical properties

In this article, aiming to develop the high performance ultraviolet (UV)-curable resin used in the polymer matrix composite, a series of polyurethane acrylate (PUA) resins with the different numbers of allyl terminal groups were elaborately designed and synthesized, in which the contents of hard segments and soft segments were also adjusted simultaneously. The effects of allyl number on properties of PUA were systemically investigated. It was found that allyl number had the negligible effect on the processability as well as positive effect on thermal performances, and all PUA resins exhibited the low viscosity and rapid UV polymerization. Besides, with the change of allyl number in the range of 2-4, PUA resin casting with three allyls possessed the preferable mechanical properties such as 85.1 MPa tensile strength, 3.94 GPa tensile modulus, and 20.7 kJ m(-2) impact strength. More importantly, the high strength and high modulus of the composite further demonstrated the wide potentials of the as-prepared PUA resin as the ideal resin matrix candidate for the fiber reinforced polymer composites. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48147.