СИНТЕЗ АМИНОСОДЕРЖАЩИХ ОЛИГОДИМЕТИЛСИЛОКСАНОВ

The process of co-condensation of 3-aminopropylmethyldimethoxysilane with α,ω-dihydroxyoligo-dimethylsiloxanes is studied. It is shown that the method proposed allows obtaining aminosiloxanes with a definite structure in quantitative yield. The methoxy group in aminopropylmethoxysiloxane oligomers can be quantitatively replaced by trimethylsiloxy group by transesterification with trimethylsilanol, leading to aminosiloxanes with the same chain length. The hydrolysis of the methoxy groups in aminopropylmethoxysiloxane oligomers causes the increase of the polymer chain length due to partial co-condensation of silanol groups leading to aminosiloxanes with a strictly alternating dimethylsiloxane block of the fixed length and a pair of aminopropylmethylsiloxane units. The reaction of N,N’-bis(trimethylsilyl)carbodiimide or hexamethyldisilazane with residual silanol groups leads to trimethylsiloxy-substituted polyaminopolysiloxanes. The trimethylsililation of the residual silanol groups with hexamethyldisilazane is accompanied by the trimethylsililation of the amino groups.Исследованы процессы соконденсации 3-аминопропилметилдиметоксисилана с α,ω-дигидрокси-олигодиметилсилоксанами различной длины, а также замещения в полученных продуктах метоксигруппы на триметилсилоксигруппу взаимодействием с различными силилирующими агентами. Показано, что данный способ синтеза позволяет получать аминосодержащие силоксаны заданного состава и строения с количественным выходом

ФУНКЦИОНАЛЬНЫЕ КРЕМНИЙОРГАНИЧЕСКИЕ ВЕЩЕСТВА - СТАБИЛИЗАТОРЫ ПОЛИМЕРНЫХ СУСПЕНЗИЙ

The review presents schemes for obtaining homologous series of the linear α,ω-carbofunctional oligodimethylsiloxanes with the silicone chain length from 6 to 60 siloxane units containing carboxydecyl, aminopropyl and glycidoxypropyl groups at the chain ends allowing to obtain organosilicon surfactants with reproducible structure and properties. Data on the surfactant colloidchemical properties and kinetic regularities of styrene polymerization in their presence are provided. Systematic research of heterophase styrene polymerization kinetic regularities in the presence of water-insoluble α,ω-carbofunctional oligodimethylsiloxane allowed to formulate the fundamental differences of polymerization kinetic regularities from those observed in the presence of water-soluble surfactants. The mechanism of interfacial adsorption layers formation with water-insoluble α,ω-carbofunctional oligodimethylsiloxanes on the surface of monomer drops and polymer-monomeric particles was considered. This mechanism consists in the forced surfactant replacement by the formed polymer (because of their incompatibility) to the interfacial adsorption layer and in the formation of the surfactant supermolecular structures. The latter in total with the polymer provide its high durability.В обзоре представлены схемы синтеза гомологического ряда линейных α,ω-карбофункциональных олигодиметилсилоксанов с длиной цепи от 6 до 60 силоксановых звеньев, содержащих карбоксидецильные, аминопропильные и глицидоксипропильные группы на концах цепей, позволяющие получать кремнийорганические поверхностно-активные вещества с воспроизводимыми структурой и свойствами. Приведены данные по коллоидно-химическим свойствам ПАВ и кинетическим закономерностям полимеризации стирола в их присутствии. Сформулированы причины принципиальных отличий кинетических закономерностей полимеризации стирола в присутствии кремнийорганических функциональных ПАВ по сравнению с закономерностями, наблюдаемыми при использовании водорастворимых ПАВ

SYNTHESIS OF AMINO-CONTAINING OLIGODIMETHYLSILOXANES

The process of co-condensation of 3-aminopropylmethyldimethoxysilane with α,ω-dihydroxyoligo-dimethylsiloxanes is studied. It is shown that the method proposed allows obtaining aminosiloxanes with a definite structure in quantitative yield. The methoxy group in aminopropylmethoxysiloxane oligomers can be quantitatively replaced by trimethylsiloxy group by transesterification with trimethylsilanol, leading to aminosiloxanes with the same chain length. The hydrolysis of the methoxy groups in aminopropylmethoxysiloxane oligomers causes the increase of the polymer chain length due to partial co-condensation of silanol groups leading to aminosiloxanes with a strictly alternating dimethylsiloxane block of the fixed length and a pair of aminopropylmethylsiloxane units. The reaction of N,N’-bis(trimethylsilyl)carbodiimide or hexamethyldisilazane with residual silanol groups leads to trimethylsiloxy-substituted polyaminopolysiloxanes. The trimethylsililation of the residual silanol groups with hexamethyldisilazane is accompanied by the trimethylsililation of the amino groups

FUNCTIONAL ORGANOSILICON SUBSTANCES AS STABILIZERS OF POLYMERIC SUSPENSIONS

The review presents schemes for obtaining homologous series of the linear α,ω-carbofunctional oligodimethylsiloxanes with the silicone chain length from 6 to 60 siloxane units containing carboxydecyl, aminopropyl and glycidoxypropyl groups at the chain ends allowing to obtain organosilicon surfactants with reproducible structure and properties. Data on the surfactant colloidchemical properties and kinetic regularities of styrene polymerization in their presence are provided. Systematic research of heterophase styrene polymerization kinetic regularities in the presence of water-insoluble α,ω-carbofunctional oligodimethylsiloxane allowed to formulate the fundamental differences of polymerization kinetic regularities from those observed in the presence of water-soluble surfactants. The mechanism of interfacial adsorption layers formation with water-insoluble α,ω-carbofunctional oligodimethylsiloxanes on the surface of monomer drops and polymer-monomeric particles was considered. This mechanism consists in the forced surfactant replacement by the formed polymer (because of their incompatibility) to the interfacial adsorption layer and in the formation of the surfactant supermolecular structures. The latter in total with the polymer provide its high durability