Preparation of Scratch and Abrasion Resistant Polymeric Nanocomposites by Monomer Grafting onto Nanoparticles, 5

Abstract

AbstractSummary: Reinforced clear coats were prepared using nanosized silica and alumina particles in UV/EB curable acrylate formulations. For a firm embedding of the oxide nanofillers via covalent bonds to the network acrylates their surfaces were modified by polymerization‐active trialkoxysilanes, e.g., methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane. The cured nanocomposite clear coats showed improved scratch and abrasion resistance. However, oxide modifications accomplished by silanes having polymerization‐inactive methyl, propyl, and isobutyl functionalities yield coatings with similar scratch and abrasion resistance. To explain these findings, infrared and multinuclear MAS NMR experiments, MALDI‐TOF and ESI‐MSn mass spectroscopy, and atomic force microscopy results were used to reveal the structure of surface‐anchored organosilanes and their interaction with the acrylate matrix. Ladder‐like polysiloxane chains chemically grafted onto the filler particles have been proposed. These ladder‐like structures build a short range interpenetrating network with the polyacrylates. This results in a durable link between the organic and inorganic phase.Proposed ladder‐like arrangement of T3 structure of silicon atoms in MEMO polysiloxanes grafted on silica surface.magnified imageProposed ladder‐like arrangement of T3 structure of silicon atoms in MEMO polysiloxanes grafted on silica surface.