Effect Of Comb Copolymer On Rheological Property Of Heterogeneous System

Casting explosive is widely used in various countries as mixed explosives which occupies an important position in the military mixed explosives. To improve its flow ability, paraffin and silica (hydrophobic system) were mixed to simulate casting explosive heterogeneous system. Model system with and without hydrophobic-modified silica were prepared to explore the interaction between silica and paraffin, particle volume fractions were changed to explore the interaction between silica particles. It indicates that the system makes an abrupt transition from shear thinning to shear thickening as the shear rate increased, the shear rates at which shear thickening occur are low as the content of silica increasing. Furthermore, changing the interaction between silica and paraffin is a effective way to improve the rheological property of heterogeneous system. Comb copolymers, poly(styrene-maleic Octadecylamine)(SMAC) with different amount of alkyl side-groups were synthesized. SMAC-1.0are effective on viscosity reduction for silica-paraffin system when the amount of SMAC is0.5%.PS core emulsion with different particle sizes were synthesized to explore the rheological property of hydrophilic system. The viscosity of emulsion is getting high upon increasing the particle size and content of emulsion. Comb copolymers, poly(styrene-maleic MPEG)(SMANP) with different amount of alkyl side-groups were synthesized. When the amount of SMANP is0.5%, SMANP with less MPEG are effective on viscosity reduction for emulsion system.Upon addition of comb copolymers, the viscosity of heterogeneous system decrease significantly measured by rheology and viscosity cup. The effect of comb copolymer on rheology property of hydrophobic system was consistent with hydrophilic system. An optimal value of the amount of comb-type copolymer exists in viscosity reduced, the grafting degree of side chain can be selected according to the polarity of system.