2633-57-0Relevant articles and documents
Environment-friendly synthesis and performance of a novel hyperbranched epoxy resin with a silicone skeleton
Zhang, Daohong,Liang, Enbin,Li, Tingcheng,Chen, Sufang,Zhang, Junheng,Cheng, Xinjian,Zhou, Jiliang,Zhang, Aiqing
, p. 3095 - 3102 (2013)
Hyperbranched epoxy resins have attracted increasing attention for their excellent comprehensive performance in toughening and reinforcing the diglycidyl ether of bisphenol-A (DGEBA). However, the tedious synthetic procedure, high cost, and the use of large amounts of organic solvents have hampered their industrial application. This paper presents an environment-friendly method to synthesize a novel hyperbranched epoxy resin with a silicone skeleton (HERSS) through a hydrosilylation reaction catalyzed by a heterogeneous halloysite-supported platinum catalyst. The reaction involves only one solvent and affords a high yield (>90%). The chemical structure, molecular weight, and degree of branching of the HERSS were characterized by FT-IR, GPC and NMR. The resulting HERSS was used to modify a DGEBA based epoxy resin and showed excellent performance. With the incorporation of 9 wt% HERSS, the impact, flexural and tensile strength of DGEBA are increased by about 92.5%, 36.0% and 88.6%, respectively. The toughening and reinforcing mechanism was attributed to the sea-island structure of the cure composite, as shown by the SEM micrographs of the fractured surfaces. An initial thermal decomposition temperature of about 380.0 °C of the cured HERSS/methyl nadic anhydride resin also indicates promising applications with regard to high-temperature- resistance.
The effect of molecular weight of hyperbranched epoxy resins with a silicone skeleton on performance
Zhang, Daohong,Liang, Enbin,Li, Tingcheng,Chen, Sufang,Zhang, Junheng,Cheng, Xinjian,Zhou, Jiliang,Zhang, Aiqing
, p. 9522 - 9529 (2013)
Hyperbranched epoxy resins with a silicone skeleton (HERSS) obtained by us through an environmentally-friendly synthetic method have shown a prominent comprehensive performance in modifying the diglycidyl ether of bisphenol-A (DGEBA). However, controlling
Zinc mediated allylations of chlorosilanes promoted by ultrasound: Synthesis of novel constrained sila amino acids
Ramesh, Remya,Reddy, D. Srinivasa
supporting information, p. 4093 - 4097 (2014/06/10)
A simple, fast and efficient method for allylation and propargylation of chlorosilanes through zinc mediation and ultrasound promotion is reported. As a direct application of the resulting bis-allylsilanes, three novel, constrained sila amino acids are prepared for the first time. The design and synthesis of the constrained sila analogue of GABA (γ-amino butyric acid) is a highlight of this work. This journal is the Partner Organisations 2014.
Controlled introduction of allylic group to chlorosilanes
Li, Zhifang,Cao, Xiaojun,Lai, Guoqiao,Liu, Jinhua,Ni, Yong,Wu, Jirong,Qiu, Huayu
, p. 4740 - 4746 (2007/10/03)
Allylation of chlorosilanes has been achieved with allylsamarium bromide, especially in a controlled manner. Thus allylation of trisubstituted chlorosilanes (R3SiCl) afforded a variety of aryl, aralkyl, and alkenyl substituted allylsilanes. Dichlorosilanes (R2SiCl2) can either afford monoallylated silanes or diallylated silanes depending on the amount of allylsamarium bromide used. Similarly, trichlorosilanes (RSiCl3) can selectively afford mono-, di-, and tri-allylation products. Finally, perchlorosilane (SiCl4) was allylated stepwise and the corresponding silanes containing one, two, three or four allylic groups, respectively, were obtained in satisfactory yields.
Carbosilane dendrons functionalized at their focal point
Andres, Roman,De Jesus, Ernesto,De La Mata, F. Javier,Flores, Juan C.,Gomez, Rafael
, p. 3742 - 3749 (2007/10/03)
The Si-Ph bond of PhSi[(CH2)3SiMe2Bz] 3 (5) is cleaved with triflic acid to give TfOSi[(CH 2)3SiMe2Bz]3, which, in turn, reacts with triethylammonium chloride or potas
Cross-coupling of triallyl(aryl)silanes with aryl bromides and chlorides: An alternative convenient biaryl synthesis
Sahoo, Akhila K.,Oda, Takuro,Nakao, Yoshiaki,Hiyama, Tamejiro
, p. 1715 - 1727 (2007/10/03)
Cross-coupling of a diverse range of aryl bromides with triallyl(aryl)silanes is effective in the presence of PdCl2/PCy 3 and tetrabutylammonium fluoride (TBAF) in DMSO-H2O to give various biaryls in good yields. It is worthwhile to note that the all-carbon-substituted arylsilanes, stable towards moisture, acid, and base and easily accessible, serve as a highly practical alternative to their aryl(halo)silane counterparts. A catalyst system consisting of [η3-C3H5)PdCl]2 and 2-[2,4,6-(i-Pr)3C6Ha]-C6H4PCy 2 and use of TBAF· 3 H2O in THF-H2O are effective especially for the cross-coupling with aryl chlorides. Both of the catalyst systems tolerate a broad spectrum of common functional groups. The high efficiency of reactions is presumably due to the ready cleavage of the allyl groups upon treatment with TBAF·3 H2O and an appropriate amount of water. Diallyl(diphenyl)silane also cross-couples with various aryl bromides and chlorides in good yields, whereas allyl(triphenyl)silane gives the cross-coupled products in only moderate yields. Through sequential cross-coupling of bromochlorobenzenes with different arylsilanes, a range of unsymmetrical terphenyls are accessible in good overall yields.
Pentacoordinate silicon complexes, the process for their preparation and their application to the preparation of organosilanes
-
, (2008/06/13)
The present invention relates to new pentacoordinate silicon complexes, the process for their preparation and their application to the preparation of organosilanes. The pentacoordinate silicon complexes according to the invention correspond to the general formula I: STR1 in which: R denotes an alkyl, alkenyl, alkynyl, aryl, aralkyl, aralkenyl, aralkynyl or alkylaryl radical in which the aliphatic fragments are linear, branched or cyclic and contain from 1 to 20 carbon atoms, A represents an alkali metal or alkaline earth metal, with the proviso however that A represents neither sodium nor potassium when R is a phenyl radical, and n=1 or 2.
