Mechanism for the Formation of Poly(phenylsilsesquioxane)

We have succeeded in development of alkalisoluble oligo-ladder phenylsilsesquioxane (oligo-LPSQ). Oligo-LPSQ was synthesized by the one-pot manner via silicon-pyridine adducts formation at aqueous-liquid boundary and finally product was obtained as white solid (85% yield) through re-precipitation in n-hexane. The obtained polymer is soluble in 2.38% TMAH (tetramethylammonium hydride). This polymer was characterized by MALDI-TOF/TOF-MS and 29SiNMR techniques. The properties of obtained polymer showed high thermal resistance over 400 °C and low dielectric constant under 3.2. Furthermore, the alkali soluble oligo-LPSQ can provide both positive and negative tone photosensitive LPSQ combination with diazonaphtoquinone (DNQ) and photo-acid (base) generator, respectively. Here we demonstrate features of synthesis method for alkali-soluble oligo-LPSQ, photolithographic character and the material properties.

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“…4 (Ph-Si(OSi-) 3 ) [10]. This further confirmed the ladder structure formation in re-precipitated polymer.…”

Section: Synthesis Of Alkali Soluble Oligo-ladder Phenylsilsesquioxansupporting

confidence: 75%

Characterization of Photosensitive Composition Based on Oligo-ladder Phenylsilsesquioxane

Tashiro

Miyazato

Ebitani

2015

J. Photopol. Sci. Technol.

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“…1 H NMR and 13 C NMR spectra were obtained on a Bruker Avance500 spectrometer (Bruker Biospin, Rheinstetten, Germany), in CDCl 3 or DMF-d 7 . IR spectra were recorded on a Perkin Elmer FT-IR 1600 (Perkin Elmer, Waltham, MA, USA).…”

Section: Experimental Procedures Generalmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12] The graft polymerization from the silsesquioxane backbone is an effective method for transforming the silsesquioxanes into practical and useful materials. [13][14][15][16][17][18][19][20] Grafted silsesquioxanes are expected to show functions based on the incorporated polymeric components without losing the essential properties of the inorganic polysiloxane structure, such as durability against heat and weatherability.…”

Section: Introductionmentioning

confidence: 99%

Graft polymerization of acrylamide monomers from polysilsesquioxane containing xanthate groups

Kashio

Sugizaki

Miyasaka

et al. 2012

Polym J

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Polysilsesquioxanes (PSQs) containing 4-chloromethylphenyl groups were prepared and used for introducing ethylxanthate groups. The obtained PSQs that contained benzyl xanthate structures (XAPSQs) were employed as macroinitiators for grafting acrylamide monomers. The use of XAPSQs for the radical polymerization with acryloylmorpholine (ACMO), N,Ndimethylacrylamide (DMAA) or N-isopropylacrylamide enabled the preparation of the respective grafted PSQ, in which no cross-linked product was formed. The results of the graft polymerizations from XAPSQs supported the interpretation that the reversible addition-fragmentation chain transfer polymerization progressed effectively using the technique known as macromolecular design via the interchange of xanthate. The introduction of polymerized ACMO and DMAA units provided an amphiphilic property to the grafted PSQ. In addition, the PSQs containing poly(ACMO) components showed reversible hydrophobic aggregation behavior at approximately 801C in aqueous solution. Polymer Journal ( The graft polymerization from the silsesquioxane backbone is an effective method for transforming the silsesquioxanes into practical and useful materials. [13][14][15][16][17][18][19][20] Grafted silsesquioxanes are expected to show functions based on the incorporated polymeric components without losing the essential properties of the inorganic polysiloxane structure, such as durability against heat and weatherability. With the regard to this expectation, we also tried to develop new multifunctional hybrid materials using acrylamide monomers by the graft polymerizations from polysilsesquioxane (PSQ). [21][22][23][24][25][26] In fact, the graftings of polymeric N,N-dimethylacrylamide (DMAA) and N-isopropylacrylamide (NIPAM) successfully produced amphiphilic and thermoresponsive PSQs. 23,24 For the graft polymerizations, the reversible addition-fragmentation chain transfer (RAFT) process was utilized, in which the N,Ndimethyldithiocarbamate (DTC) group was chosen as the chain transfer species. 24 The use of the DTC group was appropriate for designing the sequence and number of monomer units of the graft chains that were the important factors for extending grafted PSQ to a high performance hybrid material. However, in a few examples, the formation of a small amount of by-product that showed unexpectedly high number average molecular weights (M n s) was observed.

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“…Nevertheless, its structure was refuted later by Frye et al (Frye & Klosowski, 1971) who indicated that the so-called Ph-LPSQ actually was "partially opened polycyclic cages and short-range order but random on large scale". In 2004, Yamamoto et al (Yamamoto et al, 2004) reported an oligomeric polyphenylsilsesquioxane ladder with low ladder regularity. Lately, Brook (Brook, 2000) mentioned that the high Mw ladder polysilsesquioxanes reported are generally random networks, but the ladder structure may be obtained under certain controlled conditions.…”

Section: Synthesis and Characterization Of R-lpsqmentioning

confidence: 99%