Preparation and properties of some acyloxysilanes

Abstract

Acyloxy derivatives of silicon were prepared by the interchange reaction between carboxylic acids (including various grades of palmitic acid) and tetraethoxysilane, and by the interchange reaction between palmitic acid and technical ethyl silicate (silica content 40%) or technical isopropyl silicate (silica content 38%). In most of the reactions, sodium methoxide was used as catalyst. Some physical properties of the reaction products were determined, and the materials made from palmitic acid were evaluated as water‐repellent coatings on cotton cloth.

Preparation of organoalkoxysiloxanes by partial acidolysis of organoalkoxysilanes

“…Oligoorganomethoxysiloxanes are obtained of the average composition [RSi(OMe)O] 4 , [RSi (OMe) 4/6 O 7/6 ] 6 , RSi(OMe) 0.5 O 1.25 ] 8 , and [RSi(OMe) 0.4 O 1.3 ] 10 . Using the method of 29 Si NMR spectroscopy they were shown to contain three types of structural fragments: RSi(OMe) 2 O-, RSiOMe(O-) 2 , RSi(O-) 3 .…”

“…Based on the kinetic data, on the composition, properties, and the 29 Si NMR spectroscopy data of the products the conclusion is made that the obtained compounds have polycyclic structure with branched fragments. Using the GLC method the reaction was shown to have an induction period, whose duration can be substantially shortened by addition of HCl or methanol.Reactions of organoacetoxysilanes with alcohols [1, 2] and organoalkoxysilanes with organic acids [3][4][5][6][7][8][9][10][11][12][13] are an efficient method of synthesis of organosiloxanes of various composition and structure. A specific feature of these processes is the formation of the siloxane bond upon hydrolytic polycondensation in homogeneous environment due to the presence of water produced in the reaction of an acid with an alcohol.…”

“…Reactions of organoacetoxysilanes with alcohols [1, 2] and organoalkoxysilanes with organic acids [3][4][5][6][7][8][9][10][11][12][13] are an efficient method of synthesis of organosiloxanes of various composition and structure. A specific feature of these processes is the formation of the siloxane bond upon hydrolytic polycondensation in homogeneous environment due to the presence of water produced in the reaction of an acid with an alcohol.…”