| Abstract: | The sulfomethylation of nitro oligomers obtained from waste rubbers (NO‐GWR) with sodium hydroxymethane sulfonate was studied in aqueous–alkali solutions from 50 to 80°C for reaction times of 3.5–5.5 h with weight ratios of 1.0:0.3–0.6. The initial NO‐GWR was produced by the oxidation/destructive nitration of waste rubbers with nitric acid in a heterogeneous medium. The influence of the reaction conditions on the yields and functional compositions of the sodium salts of two types of N‐sulfonic acids was investigated. Some of the nitro groups transformed into sulfaminate groups at 80°C or lower. One type of N‐sulfonic acid was isolated from its sodium salt by ion exchange. The oligosulfo derivatives were characterized by elemental and thermal analyses, IR and 1H‐NMR spectroscopy, and the number‐average molecular weight. The sodium salts of the N‐sulfonic acids obtained from NO‐GWR possessed functional compositions similar to those of sodium salts from butadiene–styrene nitro oligomers prepared from butadiene–styrene latexes. Therefore, NO‐GWR obtained from available raw materials can be used as the initial derivative for the preparation of salts of N‐sulfonic acids instead of the nitro oligomers used now from elastomers. The salts can be used in galvanic coating techniques as brighteners. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1002–1013, 2005 |
