US Patent 7214649 Hydrocarbyl dispersants including pendant polar functional groups

A dispersant composition for use as a lubricant additive. The dispersant composition includes a reaction product of an acrylamide and a compound having at least one primary or secondary amine group and being selected from the group consisting of hydrocarbyl-substituted succinimides, hydrocarbyl-substituted amines, and Mannich base adducts derived from hydrocarbyl-substituted phenols condensed with aldehydes and amines. The hydrocarbyl substituent has a number average molecular weight ranging from about 500 to about 5000 as determined by gel permeation chromatography.