Synthesis and Characterization of Gold/Polymer Nanocomposites by Thermal Cationic and Radical Polymerization Processes: Initiating Systems Based on Amine and/or Silane Reducing Agents

New initiating systems based on silane (diphenylsilane (DPSi)) and/or amine (triethylamine (TEA)) and gold salt (Gold(III) chloride trihydrate (HAuCl4)) are proposed for an easy thermal cationic and/or radical polymerization of ɛcaprolactone (ɛ-CL) and trimethylolpropane triacrylate (TMPTA) at room temperature and under air. They ensure good to excellent polymerizations. Moreover, a direct incorporation of the gold nanoparticles (Au(0) NPs) through this one pot synthetic procedure is observed. We report on the use of TEA and/or DPSi as reducing agents in the formation of gold nanoparticles. We can predict whether the amine and silane will function as reducing agents in this reaction based on their redox properties. The kinetics of Au(0) NPs formation by amine can be understood in terms of Marcus electron transfer theory and by silane by an attack of the electrophile on a Si-H bond. Interestingly, using TMPTA/ɛ-CL blends are also easily polymerized at RT and under air and lead to the formation of interpenetrating polymer networks IPN exhibiting no phase separation. The as-synthesized nanocomposite materials contained nanoparticles homogeneously dispersed in the polymer matrices. The nanoparticles were characterized by X-ray diffraction (XRD), X-ray spectrometry (EDS), transmission electron microscopy (TEM), and UV-vis spectroscopy. A coherent picture of the involved chemical mechanisms is presented.