The synthesis and characterization of polyorganosiloxane nanoparticles from 3-mercaptopropyltrimethoxysilane for preparation of nanocomposite films via photoinitiated thiol-ene polymerization

Abstract

This article describes the synthesis of modified silica nanoparticles (SiO 2 -MPTMS) via the condensation reaction carried out between silanol moieties of silica nanoparticles and the trialkoxy silyl groups of (3-mercaptopropyl) trimethoxysilane (MPTMS). Then, SiO 2 -MPTMS nanoparticles in certain amounts (0.5 wt %, 1 wt %, 2.5 wt % and 5 wt %) were incorporated into thiol-ene resins consisting of bisphenol A glycerolate dimethacrylate and trimethylolpropane tris(3-mercaptopropionate) to prepare nanocomposite films via the photoinitiated thiol-ene polymerization in presence of 2,2-Dimethoxy-2-phenylacetophenone 99% as a photoinitiator. Fourier transform infrared spectroscopy, dynamic light scattering, scanning transmission electron microscopy, thermal gravimetric analyzer, and X-ray photoelectron spectrometer were employed to characterize SiO 2 -MPTMS nanoparticles. It was revealed that the nanosilica surface was successfully grafted by MPTMS with the grafting ratio of 22.9%. Properties of the nanocomposite films such as decomposition temperature, thermal glass transition temperature, tensile strength, hardness, and particle distribution were investigated and the results were compared with each other and neat film. The addition of MPTMS-modified silica particles did not improve the thermal stability of the films. In scanning electron microscopy study, it was seen that 2.5 wt % of these nanoparticles used as additives were about 200 nm in size and dispersed homogeneously in the polymer matrix. The increase in tensile strength of nanocomposite films compared to the neat film was measured as 77.3% maximum.

Preparation of Composite Hydrogels with Silica Nanoparticles by Photoinitiated Polymerization Reaction

“…For these reasons, 3-mercaptopropyl trimethoxy silane (MPTMS), which is able to undergo thiol-ene reaction due to its thiol group, has to be investigated in detail as a silane agent, which uses in modifying silica nanoparticles being involved in the preparation of various composite materials in a wide field. Although there are various studies investigating the thiol-ene click reaction for the use of surfacemodified silica nanoparticles in 3D composite systems, the number of studies in which 3mercaptopropyl trimethoxy silane agent is modified on silica nanoparticles and applied in various polymer matrices is very limited (Irmukhametova et al 2011, Kurttner et al 2013 (Karaca 2021). However, in the literature, it has not been studied to the preparation of a nanocomposite hydrogel with N-isopropyl acrylamide (NIPAM) and polyethylene glycol (PEG) containing silica nanoparticle fillers modified with MPTMS.…”