Hwang, Seon Oh Lee, Albert S. Lee, Ju Yeon Park, Sang-Hee Jung, Kevin Injoe Jung, Hyun Wook Lee, Jung-Hyun 2024-01-19T22:03:16Z 2024-01-19T22:03:16Z 2022-01-25 2018-08 0300-9440 https://pubs.kist.re.kr/handle/201004/121061 A series of ladder-like polysilsesquioxanes (LPSQs) containing the UV-curable methacryoxypropyl (MA) and different organic functional (R) groups (propyl, hexyl, cyclohexyl, phenyl or naphthyl) at the fixed MA/R molar ratio were synthesized as hard coating materials. The LPSQ hard coating films prepared by a simple UV curing process exhibited excellent optical transparency in the visible light range. X-ray diffraction analysis of the LPSQ films characterized how their intermolecular chain-to-chain distance and thus chain packing density varied according to the organic functional group. In addition, the hardness, elastic modulus and scratch resistance of the LPSQ films were evaluated by nanoindentation and nanoscratch tests. Although the mechanical properties of the LPSQ films were affected by both the chain rigidity of the organic functional group and the chain packing density of the siloxane backbones, chain rigidity played the dominant role in determining their mechanical robustness. Hence, despite its lowest chain packing density, the LPSQ film with the naphthyl group exhibited the best mechanical properties due to its high chain rigidity derived from the increased aromaticity of the naphthyl group. This study suggests the key factor when designing mechanically durable, scratch resistant hard coating films is the chain rigidity of the film network. English ELSEVIER SCIENCE SA Mechanical properties of ladder-like polysilsesquioxane-based hard coating films containing different organic functional groups Article 10.1016/j.porgcoat.2018.04.022 1 PROGRESS IN ORGANIC COATINGS, v.121, pp.105 - 111 PROGRESS IN ORGANIC COATINGS 121 105 111 N scie scopus 000438479500013 2-s2.0-85046122109 Chemistry, Applied Materials Science, Coatings & Films Chemistry Materials Science Article THERMOPLASTIC POLYSILSESQUIOXANES HYBRID NANOCOMPOSITES SILSESQUIOXANES NANOPARTICLES METHACRYLATE CHEMISTRY MEMBRANES SURFACE Ladder-like polysilsesquioxanes Silicone Hard coating films Hybrid materials Mechanical properties Scratch resistance