High Tensile Strength UV-Cured Castor Oil-Based Silicone-Modified Polyurethane Acrylates

[Image: see text] High tensile strength UV-cured transparent materials are highly desired in optical devices. In this paper, high tensile strength UV-cured transparent castor oil-based polyurethane acrylates (PUAs) with a very high transmittance over 95% (400–800 nm) were prepared from UV-curable castor oil-based polyurethane acrylates (CO-PUAs) and mercapto silicone-containing hyperbranched polymers (HBPSHs) under UV irradiation. The tensile strengths of UV-cured transparent castor oil-based PUAs can reach 12.49 MPa, which is obviously higher than that of UV-cured CO-PUAs reported previously (0.7–10.20 MPa). The chemical structure of HBPSHs will play an important role in the mechanical performance of UV-cured silicone-modified materials, and it can be concluded that the more rigid the units of α,β-dihydroxyl derivatives used in the fabrication of HBPSHs are, the higher the mechanical strength and pencil hardness of the UV-cured materials will be.