Preparation of silica/polyurethane nanocomposites by UV‐induced polymerization from surfaces of silica

Abstract

UV-curable nanocomposites were prepared by the in situ photopolymerizaton with nanosilica obtained from sol-gel process. The photoinitiator 2-hydroxy-2-methyl-1-phenylpropane-1-one (1173) was anchored onto the surface of the nanosilica with or without methacryloxypropyltrimethoxysilane (MAPS) modification. The photopolymerization kinetics was studied by real-time Fourier transform IR (RTIR), and the microstructure and properties of the nanocomposite were investigated using transmission electron microscopy and UV-visible (UV-vis) transmistance spectra. RTIR analysis indicated that the nanocomposites without MAPS had higher curing rates and final conversion than those with MAPS. The nanocomposites with an uniformal dispersion of nanosilica had high UV-vis transmittance.

The effect of processing routes on the thermal and mechanical properties of poly(urethane‐isocyanurate) nanocomposites

“…On the other side, cure temperature has also a relevant role in segmented polyurethanes, where a change in its value might cause segregation of the hard segments (HS), altering the dispersion of the nanofiller . Finally, several mixing procedures have been developed for the preparation of thermoset NC, from now on denominated routes. The main difference among those is based on which precursor the filler is dispersed.…”

Synthesis and characterization of poly(hydroxylic fluoroacrylate)/mSiO2 nanocomposite by in situ solution polymerization

“…Two necessities are required for high light transmittance; one is that the diameter of mSiO 2 nanoparticles should be less than the wavelength of visible light 44. The other is uniformly dispersed nanoparticles in the matrix, which is also confirmed by Ou and Tan in their researches 45, 46. The application of the PHFA/mSiO 2 nanocomposite will be conducted in the following research.…”

Efficient initiation of radical‐mediated thiol‐ene chemistry with photoactive silica particles

“…Whilst numerous routes have been established to alter the surface characteristics of SiO 2 and other inorganic materials, only few reports have been focusing on the immobilization of photoinitiators . Nie et al prepared photoactive silica nanoparticles via sol–gel reaction between triethoxysilyl modified 2‐hydroxy‐2‐methyl‐1‐phenylpropane‐1‐one and tetraethyl orthosilicate. FT‐IR experiments revealed that photo‐curing of urethane acrylate monomers in the presence of these modified particles leads to high conversion rates and conversion yields.…”