Synthesis and characterization of core-shell type silica-polymer composites by surface-initiated SET-LRP

ABSTRACT

A facile route for preparation of poly(tert-butyl acrylate) covalently wrapped silica nanoparticles (SiO₂/PtBA) was demonstrated by the single-electron transfer mediated living radical polymerization (SET-LRP). Firstly, the surface of silica nanoparticles (SiO₂ NPs) was modified with (3-aminopropyl) trimethoxysilane. Subsequently, a SET-LRP initiator was immobilized on the amine functional SiO₂ NPs by the Ugi reaction of 2-bromo-2-methylpropionic acid, benzaldehyde, and 1-pentyl isocyanide. The SET-LRP of tert-butyl acrylate was carried out by using copper wire and PMDTA as a catalyst system. The grafting of PtBA on the surface of SiO₂ NPs was investigated by FT-IR, XRD, TGA, and TEM analysis. Gel permeation chromatography analysis illustrated the molecular weight of PtBA increased with monomer conversion. The hydrolysis of the PtBA part yielded hydrophilic poly(acrylic acid) decorated SiO₂ NPs, which showed high colloidal stability.

KEYWORDS:

• Colloidal stability
• poly(tert-butyl acrylate)
• SET-LRP
• silica nanoparticles
• Ugi reaction

Funding

This work was supported by the Korea Industrial Complex Corporation Grant funded by the Ministry of Trade, Industry and Energy.