Abstract: Cationic rosin emulsions with tertiary amino groups(SYM-1) and with quaternary ammonium groups(JYM-1) respectively were prepared from rosin and copolymers of styrene, acrylic ester and dimethylamino ethyl methacrylate or dimethyldiallyl ammonium chloride as emulsifying agents, and their sizing performances were compared. The results showed that the electric charge density of the polymeric surfactant with tertiary amino groups(SYS-1) and the sizing performance of SYM-1 were influenced greatly by changes of pH value. The sizing degree of SYM-1 was 10 s larger than that of JYM-1 under the same condition, but SYM-1 lost its sizing performance in the papermaking system containing 10% of CaCO₃. The electric charge density of the cationic polymeric surfactant with quaternary ammonium group(JYS-1) did not change with the increase of pH value from 1 to 11. The sizing degree of JYM-1 was larger than 5 s in the system containing CaCO₃ when the complex of alum and polyvinylamine was used as anchor agent.

Key words: polymeric surfactant, cationic rosin emulsion, tertiary amino groups, quaternary ammonium groups