| Abstract: | Silicic acid esters were prepared by the reaction of the silicic acid in tetrahydrofuran with various alcohols such as such as methanol, ethanol, 2-propanol, 1-butanol, 2-methyl-2-propanol and 1-octanol, using an esterification apparatus designed especially to allow the preparation of silicic acid esters from alcohols with low boiling points or appreciable steric hindrance. With the intent of obtaining a spinnable ester solution by condensation of silicic acid esters, the effects of the degree of esterification (DE) and alkyl group on gel time and spinnability are investigated. An increase in the DE and the size of the alkyl group led to an increase in the gel time of the esters. Esters solutions with a good spinnability were prepared from n-butyl and isopropyl esters with DEs of 40–50%. In addition, the gel permeation chromatography of condensing esters with low DEs showed a rapid increase in molecular weight. The results showed that spinnability depended on DE and the ester's alkyl group. Fibers could be formed with length of about 10–100 cm from ethyl, isopropyl, and n-butyl esters with DEs 40–50% and with length of 10 cm from octyl ester with DE 26%. |
