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Suita, Japan

Kaneko Y.,Kagoshima University | Imamura H.,Kagoshima University | Sugioka T.,Nippon Shokubai | Sumida Y.,Nippon Shokubai
Polymer (United Kingdom)

In this study, a series of soluble polysilsesquioxanes (PSQs) containing hydrophobic side-chain groups (PSQ-Ph, PSQ-CyC6, PSQ-C6, and PSQ-C11) were prepared by the facile reaction of a ladder-like PSQ containing ammonium groups with the corresponding hydrophobic carboxylic acid chlorides (i.e., benzoyl, cyclohexanecarbonyl, heptanoyl, and dodecanoyl chlorides, respectively) in the presence of triethylamine in a mixed solvent of water and N,N-dimethylformamide. The resulting hydrophobic PSQs were soluble in chloroform. The weight-average molecular weights of the hydrophobic PSQs estimated by gel permeation chromatography with chloroform as the eluent and polystyrene standards ranged from 1.92 × 104 to 6.49 × 104. The pyrolysis temperatures of PSQ-Ph estimated by thermogravimetric analyses were relatively high (Td5 = 391°C and Td10 = 425°C) due to the presence of the thermally stable phenyl side-chain groups and Si-O-Si main-chain. Moreover, hybrid films of the hydrophobic PSQs and two organic polymers, poly(methyl methacrylate) (PMMA) and polystyrene (PS), were prepared by drying the chloroform solutions of the mixtures of these polymers. The PMMA/PSQ-C6, PMMA/PSQ-C11, and PS/PSQ-Ph hybrids were highly transparent. For PS/PSQ-Ph hybrid films, the thermal stability increased with increasing amount of PSQ-Ph. © 2016 Elsevier Ltd. All rights reserved. Source

Arake T.,Kagoshima University | Shikinaka K.,Tokyo University of Agriculture and Technology | Sugioka T.,Nippon Shokubai | Hashimoto H.,Nippon Shokubai | And 2 more authors.
Polymer (United Kingdom)

In this study, we found that 1-pentanol dispersion of multi-walled carbon nanotube (MWCNT) was obtained when ultrasonication of MWCNT was performed in 1-pentanol solution of ammonium group-containing polysilsesquioxane with triiodide anions (PSQ-I3). Dispersibility of MWCNT in 1-pentanol was first investigated by the presence of absorption at 750 nm in UV-Vis measurements. In addition, the number-average particle size estimated by dynamic light scattering measurement of 1-pentanol dispersion of MWCNT/PSQ-I 3 was assessed to be 120.3 ± 34.8 nm. The dispersion passed through a membrane filter with ca. 7 μm pores, indicating that large MWCNT aggregates in micrometer scale did not exist in 1-pentanol. Furthermore, the transmission electron microscopy image of the sample obtained by drying 1-pentanol dispersion of MWCNT/PSQ-I3 showed many lines with ca. 10 nm diameter derived from MWCNT, indicating that MWCNTs were individually dispersed in PSQ matrix. © 2013 Elsevier Ltd. All rights reserved. Source

Miyauchi S.,Kagoshima University | Sugioka T.,Nippon Shokubai | Sumida Y.,Nippon Shokubai | Kaneko Y.,Kagoshima University
Polymer (United Kingdom)

Abstract In this study, polysilsesquioxane (PSQ) containing phthalimido side-chain groups (PSQ-PI) with solubility and high thermal stability was prepared by the two-step reaction of an ammonium-group-containing soluble ladder-like PSQ (PSQ-NH3Cl) with phthalic anhydride. First, the reaction of PSQ-NH3Cl with phthalic anhydride was performed in the presence of triethylamine in a DMSO/water mixed solvent to obtain PSQ containing phthalamic acid side-chain groups (PSQ-PA). Next, PSQ-PI was prepared by refluxing a solution of PSQ-PA in DMF with stirring. PSQ-PI was soluble in organic solvents such as chloroform, DMF, and DMSO. The film of PSQ-PI could be prepared by drying its solution in DMF. The UV-Vis spectrum of PSQ-PI cast film showed high transmittance in the visible wavelength region. The pyrolysis temperatures of PSQ-PI under nitrogen flow were relatively high (Td5 = 394 °C and Td10 = 438 °C) because PSQ-PI has both a thermally stable Si-O-Si main-chain and phthalimido side-chains. © 2015 Elsevier Ltd. All rights reserved. Source

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