Effects of\nComposition and Cure Parameters on the\nMechanical and Optical Properties of Silicone/Methacrylate Hybrid\nElastomers

Hybrid silicone–organic materials offer an alternative\nformulation\nfor tough, silicone based elastomers. While such systems can be synthesized\nusing a simple UV-copolymerization scheme between end-functional polydimethylsiloxane\n(PDMS) and methacrylate monomers, the unique morphologies of the resulting\nmaterials complicate the establishment of clear structure–property\nrelationships. In this work, we study the effects of composition and\ncure parameters on the mechanical and optical properties of PDMS/polymethacrylate\nhybrid elastomers. We observed that differences in the mixing thermodynamics\nbetween methacrylate and silicone components lead to hybrid materials\nwith substantially different properties. Based on the observed trends,\nwe further argue that both increases in UV curing intensity and PDMS\nchain length reduce the graft density in these hybrids, leading to\nshared changes in stiffness, extensibility, and transparency. Lastly,\nwe characterize the linear and nonlinear viscoelasticity of these\nnetworks to relate the presence of mechanical dissipation to improved\ntoughness.