Hits:

Indexed by:期刊论文

Date of Publication:2011-02-08

Journal:MACROMOLECULES

Included Journals:Scopus、SCIE、EI

Volume:44

Issue:3

Page Number:566-574

ISSN No.:0024-9297

Abstract:Novel polymethacrylate-functionalized octaphenylsilsesquioxanes (OPS) macromonomer was designed and synthesized, which was employed as nanofiller and cross-linker to copolymerize with MMA to produce OPS/PMMA hybrid nanocomposites with OPS contents ranging from 0 to 1.18 mol %. The synthesis route was that, OPS was brominated to yield polybromo-OPS, and polybromo-OPS was then reacted with BuLi and CO2 to obtain polycarboxyl-OPS. After that, the carboxyls were converted to chlorocarbonyl groups, and the esterification reaction of polychlorocarbonyl-OPS with 2-hydroxyethyl methacrylate led to polymethacrylate-OPS. Their chemical structures were characterized by means of FTIR, H-1 NMR and C-13 NMR spectra. Moreover, after cleavage of C-Si bond by KF/H2O2, the position and number of functional groups on the benzene rings of OPS macromonomers and the molecular weight of PMMA in the nanocomposite were investigated in detail by LC-MS and GPC methods, respectively. The prepared OPS macromonomer can result into PMMA significantly improved thermal-chemical stability and apparently increased glass transition temperature. For example, the nanocomposites are insoluble in any common organic solvents due to the formation of three-dimensional networks. Compared to the pure PMMA, the OPS/PMMA nanocomposite with OPS content of only 0.94 mol % exhibits increased 5%-mass-loss temperature and glass transition temperature by 104 and 21 degrees C, respectively.