Synthesis of Poly(tetramethyl-m-silphenylenesiloxane), an Elastomer of Enhanced High-Temperature Stability

Synthesis of vinyl substitute poly(silphenylene‐siloxane) via silyl hydride‐dialkoxysilane process

“…1,4-dibromobenzene (2), 98%, purchased from LongShen Fine Chemical Co. (Yangcheng City, China). Dimethylchlorosilane (3) and B(C 6 F 5 ) 3 were purchased from Fluka. Vinylmethyldimethoxysilane (4) was purchased from Aldrich (Milwaukee, WI).…”

“…Poly (silphenylene-siloxane) is one kind of candidates for high-temperature polymers that do not generate hazardous gases during thermal decomposition. Polysilphenylene-siloxane is generally prepared by polycondensation of difunctional organosilanes or oligosiloxanes, such as dehydration of 1,4-bis(hydroxydimethylsilyl) benzene (BHSB) and 1,3-bis(hydroxydimethylsilyl)benzene, 3 condensation polymerization of BHSB and bis(dimethylamino)-, [4][5][6][7][8] bisureido-, 9,10 or dichlorodialkylsilanes. 6,11 Dehydrogenative coupling of orgnohydrosilanes and organosilanols or other compounds with active hydrogen such as water is particularly convenient due to its high selectivity and easy removal of the byproduct, hydrogen.…”

“…Moreover, silanol self-condensation may accompany this process, leading to disruption of the desirable perfectly alternating architecture. Silyl hydrides/B(C 6 F 5 ) 3 , generally Ph 3 SiH/B(C 6 F 5 ) 3 or Et 3 SiH/B(C 6 F 5 ) 3 is a useful system in organic chemistry, particularly in the transformation of aldehydes, ketones, alcohol, carboxylic acids, and their derivatives into silyl ethers or hydrocarbons. [20][21][22][23][24][25][26][27][28][29] B(C 6 F 5 ) 3 catalyzed coupling reaction of silyl hydrides with alkoxysilanes was a newly developed methods to prepare linear polysiloxanes by Rubinsztajn and coworkers.…”

“…[20][21][22][23][24][25][26][27][28][29] B(C 6 F 5 ) 3 catalyzed coupling reaction of silyl hydrides with alkoxysilanes was a newly developed methods to prepare linear polysiloxanes by Rubinsztajn and coworkers. 30,31 This reaction takes place at or below room temperature in the presence of very low levels of B(C 6 F 5 ) 3 . The rate of the reaction can be controlled by the rate of addition of reagents.…”

Functionalized Poly(tetramethyl-1,4-silphenylenesiloxane) with Pendant Hydroxyl Groups

“…2 On the other hand, poly(tetramethyl-1,4-silphenylenesiloxane) (1,4-PTMPS) is the representative polymer where an aromatic moiety is incorporated into the polysiloxane backbone, [3][4][5] which would presumably improve the good properties of polysiloxane, especially the thermostability. It has been reported that the properties of poly(tetramethylsilarylenesiloxane) derivatives depend on the kind of arylene moiety, [4][5][6][7][8][9][10][11][12] the substituted position of dimethylsilyl groups 8,9,13 as well as the substituent 5,[14][15][16] on the arylene moiety. For instance, 1,4-PTMPS derivatives having oxyethylene groups on the phenylene moiety have been reported to exhibit the lower thermostability compared with 1,4-PTMPS, the crystallinity of which was mainly dependent on the oxyethylene groups on the phenylene moiety.…”