Synthesis and characterization of differently substituted phenyl hepta isobutyl‐polyhedral oligomeric silsesquioxane/polystyrene nanocomposites

Abstract

Variously substituted polyhedral oligomeric silsesquioxanes (POSSs)/polystyrene (PS) nanocomposites of general formula R 7 R 0 (SiO 1.5 ) 8 /PS (where R 5 isobutyl and R 0 5 4-methoxyphenyl, 4-methylphenyl, 3,5-dimethylphenyl, 4-fluorophenyl, 2,4-difluorophenyl, 4-chlorophenyl) were prepared by in situ polymerization of styrene in the presence of 5% w/w of POSS. The actual filler concentration in the obtained nanocomposites was checked by 1 H NMR spectroscopy. Scanning electron microscopy and FTIR spectroscopy evidenced the presence of filler-polymer interactions. Inherent viscosity (g inh ) determinations indicated that the average molar mass of polymer in halogenated derivatives was lower than neat PS, and were in agreement with calorimetric glass transition temperature (T g ) measurements. Finally, a comparative study concerning the thermal stability of synthesized nanocomposites was carried out in both inert (flowing nitrogen) and oxidative (static air) atmospheres into a thermobalance, in the scanning mode, at 10 C min 21 , and the temperatures at 5% mass loss (T 5% ), of various compounds were determined. The results were discussed and interpreted. POLYM. COMPOS.,

Synthesis and thermal characterization of new dumbbell shaped POSS/PS nanocomposites: Influence of the symmetrical structure of the nanoparticles on the dispersion/aggregation in the polymer matrix

“…We first tried clay as filler for PS and recently we focused our attention on POSS nanoparticles. We thus synthesized and characterized some hetero‐substituted POSSs and then we carried out other investigations to verify if and at which filler contents these NMs give rise to PNMs with better thermal properties than neat PS . The results obtained evidenced higher thermal stability than both pristine polymer and clay/PS nanocomposites , furthermore we observed an enhancement of thermal properties on increasing filler contents up to 5% POSS about .…”

“…The aim of this study was to investigate if and how much the presence of the diphenyl thioether bridge in the molecule, and the POSS amount in the matrix, influence the thermal properties of nanocomposites in respect to neat PS and diphenyl ether bridged POSS/PS systems previously studied . The parameters associated with the thermal stability of various nanocomposites, namely temperature at 5% mass loss ( T 5% ) and apparent activation energy ( E a ) of degradation, were thus determined, compared with each other, with those of pristine polymer and those of the POSS/PS nanocomposites studied by us in the past .…”

A Rapid One-Pot Synthesis of Novel High-Purity Methacrylic Phosphonic Acid (PA)-Based Polyhedral Oligomeric Silsesquioxane (POSS) Frameworks via Thiol-Ene Click Reaction

“…Additionally, it has strong attention due its unique physico-chemical properties and reactive organic terminal functional substituents [4][5][6][7][8]. The three-dimensional structure of the silicon-oxygen (Si-O) core is inevitably responsible for high thermal stability and stiffness, whereas the terminal organic reactive functional groups can be enabled to make the covalent bond between POSSs and polymers, which results in the solid progress of organic-inorganic hybrid materials [9,10].…”

Tripodal polyhedral oligomeric silsesquioxanes as a novel class of three-dimensional emulsifiers

“…From this point of view, polyhedral oligomeric silsesquioxanes (POSSs) [17][18][19][20][21] are one of the most suitable candidates because of their precisely defined three-dimensional structure. POSSs have been widely used as fillers, [22][23][24][25][26][27] cross-linkers, 28-33 monomers [34][35][36][37] and substituents to polymer side chains, [38][39][40][41][42][43] to attain high performance. To obtain a POSS emulsifier, the basic strategy is the construction of amphiphilic POSS derivatives.…”