Polymer-Titanium hybrids obtained by radical polymerization and Sol-Gel process

Abstract

The possibility to prepare hybrids made by poly(vinyl acetate) (PVAc), poly(methyl methacrylate) (PMMA) and/or poly(ethyl acrylate) (PEtA) with TiO 2 was studied. The processes of polymer formation -radical polymerization and sol-gel process for inorganic network -were achieved simultaneously. Due to a high reactivity of titanium isopropoxide (TIP) in the sol-gel process, a complexant comonomer, allyl acetoacetate (AlAcAc), was used. Covalent bonds between polymer and inorganic chains were obtained by addition of trialkoxysilane derivates with vinyl (VTES) or methacryloyl (MPTS) groups. The presence of TIP inhibits the radical polymerization of vinyl acetate (VAc). The PVAc-TiO 2 hybrids were produced by the sol-gel process of TIP in the presence of pre-obtained PVAc. Except for VTES and MPTS, trialkoxysilane derivates with methyl (MeTES), octyl (OTES) and phenyl (PTES) groups were used. The thermal stability of hybrids is strongly affected by TiO 2 presence and by the type of trialkoxysilane derivates. The thermal stability of PVAc hybrids decreases in the presence of TiO 2 inorganic network. The glass transition temperature of polymers increases in the presence of the inorganic network.

Filmogen organic–inorganic hybrids obtained by sol–gel in the presence of cationic polymer

“…for Me‐TIP granules when compared with particle made from pure MeTES) and, hence, a different interaction of the organic chains with the inorganic matrix. The second explanation can be a catalytic effect of TiO 2 on the thermal oxidation 28…”

“…The second explanation can be a catalytic effect of TiO 2 on the thermal oxidation. 28 TIP presence in the initial recipes also stimulates an advanced thermal degradation at temperatures above 4008C [ Fig. 3(d)].…”

Synthesis and characterisation of organic-inorganic hybrid polymers: Polystyrene-SiO2 & Polystyrene-TiO2

“…En toda la serie se observó una disminución de la T g ; esto podría explicarse asumiendo que el rol principal de las partículas sobre el nanocomposito es el de actuar como agentes plastificantes cuyo efecto es el aumento del volumen libre y la mejor movilidad entre cadenas de polímeros, [70]. Se ha sugerido que las partículas de SiO 2 orgánicamente modificadas pueden actuar como unidades "suaves" en las cadenas macromoleculares después de una polimerización in situ, [30].…”

“…[71][72]. Esta disminución general en las T g , se debe a que las partículas cerámicas actúan como agentes plastificantes cuyo efecto principal es aumentar el volumen libre e incrementar la movilidad entre cadenas de polímeros, [70].…”

Aqueous dispersions of silver nanoparticles in polyelectrolyte solutions

“…VAc-MA copolymer was prepared in acetone, in the presence of AIBN, as described previously. 18 The resulting copolymer was hydrolysed and neutralized using aqueous NaOH, and then the acetone was removed by distillation. The resulting mixture was diluted with water to the desired concentrations: 10%, 1% and 0.1% wt.…”