ISSN:
1572-8870
Keywords:
Sol-gel process
;
SiO2 networks
;
polysiloxane
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Poly(dimethylsiloxane)-SiO2 organic-inorganic hybrid networks were synthesized by a two-step, catalyst-free sol-gel process. Reactive PSX (polydimethylsiloxane) oligomers with methoxysilyl end-groups were used as the organic component, and tetramethylorthosilicate (TMOS) as the inorganic component of the hybrid. Our studies show that uncatalyzed sol-gel reactions based on TMOS can reach gelation in 7.5 h when reacted at room temperature, with a stoichiometric amount of water necessary for complete hydrolysis in the initial stages, and at a high concentration of reacting species. The relatively neutral reaction environment of this catalyst-free process is important in the synthesis of PSX-SiO2 hybrid networks because it prevents redistribution reactions of PSX modifiers, especially when higher temperatures are used for the drying of the gels. The PSX-SiO2 hybrid networks have reduced polarity, increased water resistance, and improved toughness compared to inorganic SiO2 networks produced under similar conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00696539
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