Synthesis of telehelic oligodimethylsiloxanes with 4-carboxypyrrolidone fragments: rheological and thermal properties

Telehelic oligodimethylsiloxanes containing 4-carboxypyrrolidone fragments were synthesized by the reactions of oligodimethylsiloxanes bearing terminal 3-aminopropyl groups with itaconic acid. The thermal and rheological properties of the obtained polymers were studied. The activation energies of viscous flow of the oligomers obtained and the previously synthesized oligodimethylsiloxanes containing terminal fragments of undecenoic or benzoic acid are compared.

     

New star-like polydimethylsiloxanes: synthesis,properties, and application

Russian Chemical Bulletin - New star-like polydimethylsiloxanes with a cis-tetraphenylcyclotetrasilsesquioxane fragment as the core (branching center) were synthesized and characterized. The...     

Synthesis of alkoxybenzylmethylsilanes and polybenzylmethylsiloxane polymers on their basis

Russian Chemical Bulletin - An efficient solvent-free procedure for the preparation of alkoxybenzylmethylsilanes by organomagnesium synthesis was developed. The reaction conditions gave the high...     

Synthesis and Thermal and Rheological Properties of Polydimethylsiloxanes Modified with Benzoic Acid Fragments

4-(Dimethylvinylsilyl)benzoic acid is obtained by organolithium synthesis. Polydimethylsiloxanes containing silicon hydride groups are modified by introducing benzoic acid fragments via the hydrosilylation reaction. The thermal and rheological properties of the copolymers formed are studied. It is found that a rise in the content of benzoic acid results in a shift in the glass-transition temperature to a higher temperature region and the copolymers do not crystallize. Benzoic acid fragments improve the intermolecular interaction of polydimethylsiloxane chains more strongly than the ones of undecenoic acid.     

Modification of carbonyl iron particles by carboxyl-containing polydimethylsiloxanes

The possibility of preparing magnetic particles with the “core–shell” structure was demonstrated. The procedure is based on the treatment of carbonyl iron particles with polydimethylsiloxanes (PDMS) containing terminal or distributed over the chain carboxyl groups attached via the alkyl or aryl spacer. The presence of carboxyl-containing PDMS grafted to the surface of carbonyl iron particles was revealed by electron microscopy. Magnetorheological fluids and magnetic elastomers containing magnetic particles with the “core–shell” structure were obtained, and their rheological properties were studied.