Several Chemical Modifications of Styrene-Butadiene Popcorn

Abstract

Chemical modification of styrene-butadiene popcorn (SBP), a by-product in the production of styrene-butadiene rubber (SBR), has been made for its utilization. The cross-linking reaction of SBP with sulfuric acid in carbon tetrachloride resulted in an increase in cross-linking of SBP. The reaction products with' higher concentration of sulfuric acid swelled much less in benzene. A similar reaction using BF₃ Et₂O or SnCl₄ as an acid-catalyst gave no increase in cross-linking of SBP. Sulfonation, nitration and chloroxpethylation of SBP introduced the corresponding functional groups by 2∼3 mmol per 1g of SBP. Reduction of the nitrated SBP with SnCl₂ converted it into the amino-SBP, which showed the ion exchange capacity of 2.5meq/g. Moreover, reactions of chloromethylated SEW with potassium cyanide, followed by hydrolysis with sulfuric acid in aqueous acetic acid, led to the introduction of the carboxyl group in SBP.