Quaternary methyl carbonates: Novel agents for fabric conditioning

Preparation of quaternary ammonium compounds from various tertiary amines and the (environmentally friendly) alkylating agent dimethyl carbonate (DMC) under conditions within the bounds of industrial production has been carried out. After unsuccessful attempts to catalyze and entrain the process, the reaction has been accelerated by using a 10-fold excess of alkylating agent. The recovered DMC and solvent have been recycled in up to five subsequent batches without loss of rate or yield. The expected steric hindrance effects on the rate were evidenced by comparison of the half-lives of dihydrogenatedtallowmethylamine (1 h), tributylamine (4 h), and the ester quat (7.5 h). The product methyl carbonate quaternaries have been shown to be noncorrosive to 316 stainless steel for extended periods at elevated temperatures.