Synthesis of comb-like polymeric surfactants with a tricyclic rigid core and their use as dispersants in pymetrozine water suspension concentrates

Comb-like polymeric surfactants with a tricyclic rigid core have been synthesized from rosin. Their structures were confirmed by IR and H-1 NMR spectroscopies and GPC. The surface activities of these surfactants were evaluated according to critical micelle concentration (CMC), the surface tension at CMC (gamma(CMC)), emulsification properties (EP), and foam properties (FP). Their CMC values were 0.004-0.023 g L-1, which were much smaller than those of the surfactant without a rigid core (14.59 g L-1). Measurement of the rheological properties revealed that the surfactant solutions at 50 g L-1 were dilatant fluids. A break point in the viscosity-shear rate curve moved to a high shear rate when the proportion of the monomer with a rigid core increased. The dispersing and stabilizing properties of these surfactants as dispersants were investigated to prepare pymetrozine water suspension concentrates. The results indicated that surfactants with a rigid core had good grinding and dispersion effects, the suspension rate of the pymetrozine water suspension concentrates was higher than 95%, and the water suspension concentrates had good stability during the cold storage process. The introduction of a rigid core into polymeric surfactants can effectively improve the surface activities of these surfactants and the suspension rate and stability of water suspension concentrates.