Preparation a Thiol Siloxane Colloid for UV-Curable Organic-Inorganic Films Based on Norbornene Linseed Oil

摘要

A new thiol siloxane colloid was developed for UV- curable inorganic and organic hybrid films. The thiol siloxane colloid was prepared from mercaptopropyltrimethoxysilane (MPTS) via a sol-gel method. The thiol siloxane colloid structure was characterized using ~1H NMR, ~(29)Si NMR, FT-IR and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). The particle size of the thiol siloxane colloid was evaluated using small angle light scattering (SALS), and particle size and dispersion in organic matrix was observed using atomic force microscopy (AFM). Organic phase was based on norbornene linseed oil (NLO) which was synthesized using linseed oil and dicyclopentadiene, and was characterized by gel-permeation chromatography (GPC) and FT-IR. A photoinitiator was added to the formulation and the UV-crosslinking reaction of the hybrid film was monitored via photo-differential scanning calorimetry (Photo-DSC) and real-time infrared spectroscopy (RT-IR). The polymerization rate was investigated as a function of UV-light intensity as well as concentration of thiol siloxane (MPTS) colloids and photoinitiator. Photo-DSC and RT-IR results indicated that thiol siloxane (MPTS) colloids can greatly increase the free radical polymerization rate, and the MPTS colloids functioned effectively as a photoinitiator and crosslinker. Atomic force microscopy (AFM) data showed that the silica colloids were well dispersed in the organic phase.