Hybrid PMMA combined with polycarbonate inside interpenetrating polymer network architecture for development of new anti-scratch glass

[Display omitted] •Nanoparticles homogeneously dispersed act as PMMA cross-linker.•Transparent and UV-stable hybrid PMMA-SiO2 network obtained.•Hybrid PMMA-SiO2/PCR39® IPNs synthesized via in situ process without solvent.•Nanoparticles stain PMMA phase in IPN•Nanoparticles improve PMMA-SiO2/PCR39® IPN’s anti-scratch properties. Polymethyl methacrylate (PMMA) is commonly used as organic glass for the protection of works in museums. However, their extreme sensitivity to scratching causes problems during maintenance procedures. In order to improve the resistance to abrasion, PMMA has been cross-linked with silica nanoparticles previously modified with 3-(methacryloxy)propyl-trimethoxysilane (MPTS). This functionalization allows both a homogeneous dispersion of the silica nanoparticles in MMA monomer and the PMMA crosslinking which has been confirmed by solid/liquid extraction and DMA analysis. The small nanoparticles (7–10 nm diameter) added in different amounts, are homogeneously dispersed in the transparent (T% > 80%) hybrid PMMAx-SiO2 networks as verified by TGA and TEM microscopy. These hybrid PMMAx-SiO2 networks have been then combined with a PCR39® polycarbonate network in an interpenetrating polymer network (IPN) architecture. The synthesis of a hybrid IPN in which one of the phases is cross-linked by the inorganic nanoparticles has been demonstrated for the first time. Finally, as expected, the incorporation of the silica nanoparticles improves the scratch resistance by a factor of 3 compared to all organic PMMA/PCR39® IPNs.