Interactions between a graft copolymer of polyvinylpyrrolidone and butene (AGRIMER™ AL10-LC)2 and ligninsulfonates were demonstrated by surface tension measurements. Two types of ligninsulfonates: LSA and LSB showed differences in their surface activities. A surface tension lowering effect was observed with the more surface-active ligninsulfonate (LSB) and graft copolymer. However, no such effect was found with the less surface-active ligninsulfonate (LSA). When the mixed system [graft copolymer + LSA] and [graft copolymer + LSB] were stored at 52°C for 4 months, the surface tension of water in the region below the surface saturation region was lowered for LSA and increased for LSB when compared with room temperature samples. There was no apparent change in storage under the above conditions in the macroscopic properties of the components. The change in the surface activity on accelerated storage at high temperature is hypothesized to arise from changes in the conformation of the components in the matrix.
Adsorption of the graft copolymer, LSA and LSB individually and in combination onto an active ingredient (chlorothalonil) was also studied via surface tension concentration profiles. The results are consistent with preferential adsorption of the graft copolymer in the presence of ligninsulfonate on chlorothalonil.