Preparation, T_g improvement, and thermal stability enhancement mechanism of soluble poly(methyl methacrylate) nanocomposites by incorporating octavinyl polyhedral oligomeric silsesquioxanes

Abstract

The soluble poly(methyl methacrylate-co-octavinyl-polyhedral oligomeric silsesquioxane) (PMMA-POSS) hybrid nanocomposites with improved T g and high thermal stability were synthesized by common free radical polymerization and characterized using FTIR, high-resolution 1 H NMR, 29 Si NMR, GPC, DSC, and TGA. The POSS contents in the nanocomposites were determined based on FTIR spectrum, revealing that it can be effectively adjusted by varying the feed ratio of POSS in the hybrid composites. On the basis of the 1 H NMR analysis, the number of the reacted vinyl groups on each POSS molecules was determined to be about 6-8. The DSC and TGA measurements indicated that the hybrid nanocomposites had higher T g and better thermal properties than the pure PMMA homopolymer. The T g increase mechanism was investigated using FTIR, displaying that the dipole-dipole interaction between PMMA and POSS also plays very important role to the T g improvement besides the molecular motion hindrance from the hybrid structure. The thermal stability enhances with increase of POSS content, which is mainly attributed to the incorporation of nanoscale inorganic POSS uniformly dispersed at molecular level.

Hydrophobic modification of polymethyl methacrylate as intraocular lenses material to improve the cytocompatibility

“…POSS has regular structure, good biocompatibility, small scale and large surface area, which make POSS as one of the most potential next generation biomaterials. POSS macromers with different shells have been doped into polystyrene [24], PMMA [25,26], polyurethane [27], polyethylene [28], ethylene-propylene [29], etc. by the way of copolymerization with other polymer monomers to change its mechanic, thermodynamic, surface or biological properties.…”

Structure and property of tetrafluoroethylene‐propylene elastomer‐OVPOSS composites

“…This utilization ratio is much lower than that reported in the literature. 25,26 This discrepancy may be attributed to the high OVPOSS content.…”

Donut-like hybrid latex comprising discrete thermoplastic lobe and thermosetting shell

“…In spite of this, a previous study proposed the copolymerization of OVPOSS with styrene in the presence of substantial amount of the latter [20]. Most often, the free-radical polymerization of OVPOSS and a vinyl monomer in a homogeneous system results in composites, such as methyl [21][22], acetoxystyrene [23], vinylpyrrolidone [24], N-isopropylacrylamide and N,N-dimethylaminoethyl methacrylate [25] and etc. In contrast, OVPOSS has seldom been used to prepare latex particles, except that Wang et al [26] has reported a synthesis of an OVPOSS-PS latex composite with a POSS enriched core.…”