PMMA nanocomposites and gradient materials prepared by means of polysilsesquioxane (POSS) self-assembly

Abstract

PMMA nanocomposites were prepared by means of self-assembly of polyhedral oligomeric silsesquioxanes (POSS) such as [Si8O12(OSiMe2H)(8)] (POSS1) and [Si7O9(cyclohexyl)(7)(OSiMe2H)(3)] (POSS2) during the free radical methyl methacrylate (MMA) bulk polymerization. The POSS phases separation and self-assembly afforded in situ nanocubes with average diameters ranging from 25 nm to 500 nm. The influence of 5.3 wt.% POSS on the thermal, mechanical and morphological PMMA nanocomposite properties was investigated. POSS mediated nanocube formation was accompanied by improvements of PMMA glass temperature and toughness. Depth profiling by means of ion beam Rutherford backscattering (RBS) analysis indicated the accumulation of POSS1 at the PMMA surface

Microstructure and Indentation Behaviour of Polyhedral Oligomeric Silsesquioxanes‐Modified Thermoplastic Polyurethane Nanocomposites

“…[1] During the last decades a high number of reports about polymeric POSS nanocomposites partly reviewed [2,3] have been published by different authors also dealing with POSS-modified polyurethane (PU) materials. [4][5][6][7][8][9][10][11][12] Some contributions are available which give information about the bulk mechanical properties of POSS nanocomposites outside the deformation range of linear response such as stress-strain behaviour at tensile loading, [6,8,[13][14][15][16][17][18][19] flexural behaviour at three-point bending test [20,21] or fracture behaviour. [7,16,22] Incorporation of POSS molecules into PU leads to an improvement in elastic modulus [6,8] but a decreasing ductility, [6] which can be attributed to the attachment of rigid POSS molecules at the molecular level and the improved miscibility between the hard and soft segments.…”

Phenyl hepta cyclopentyl – polyhedral oligomeric silsesquioxane (ph,hcp-POSS)/Polystyrene (PS) nanocomposites: the influence of substituents in the phenyl group on the thermal stability

“…composites [23][24][25][26][27][28][29]. The general formula of POSSs is (RSiO 1.5 ) n , or R n T n , where organic substituents (R = alkyl, aryl or any other) are attached to silicon cage.…”

Synthesis of Hybrid Nanocomposites Based on Polyhedral Oligomeric Silsesquioxane Using Atom Transfer Radical Polymerization

“…17 Toepfer prepared crosslinked methacryloxypropyl -POSS/PMMA nanocomposites by copolymerization. 18 Zhao et al prepared octavinyl-POSS (OV-POSS)/ PMMA nanocomposites. 19 In this article, we prepared a star-shaped POSS/PMMA hybrid polymer using octa(γ -chloropropyl) polyhedral oligomeric silsesquioxane as the initiator in the presence of Bpy and CuCl, and the chemical structure of the POSS/PMMA hybrid polymer was fully established by FT 1 H NMR, XRD, and GPC.…”