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Synthesis of star‐shaped polydimethylsiloxanes containing SiO 2 core units
Author(s) -
Ogawa Takuya,
Suzuki Toshio,
Mita Itaru
Publication year - 1994
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1994.021950608
Subject(s) - polydimethylsiloxane , polymer chemistry , chlorosilane , polymer , silicate , star polymer , solvent , materials science , star (game theory) , chemistry , chemical engineering , silicon , copolymer , organic chemistry , composite material , mathematical analysis , mathematics , engineering
Star‐shaped polysiloxanes consisting of SiO 2 cores and polydimethylsiloxane (PDMS) branches were successfully prepared by three methods using functionalized solvent‐soluble silicates as a starting material. The first method involved the lithiation of a SiOH functional silicate with butyllithium, followed by reaction with hexamethylcyclotrisiloxane (D 3 ) and termination with a chlorosilane to afford a star polymer. In this case, the chain ends were substituted with vinyl or SiOH functional groups. In the second method, a SiCl functional silicate was used as the source of the SiO 2 core. A PDMS chain with a lithium silanolate terminal group was reacted with the SiCl functional silicate to provide a star polymer. In the third method, a PDMS chain with a diethylamino group at one chain end was reacted with the SiOH functional silicate to form a star polymer. The Mark‐Houwink constant a of the star polymer was 0,74, which is very close to that of a linear PDMS.