Preparation and properties of long-chain grafting drag-reducing film

The long-chain polymers have been applied to drag reduction of pipeline and obtained remarkable effect, but the effective acting time of its coating is very short for being applied to drag reduction of watercraft. In order to solve the problem of long-chain polymers, the polyacrylamide long-chain molecules were fixed to water-borne epoxy substrate by graft copolymerization for synthesizing long-acting long-chain grafting drag-reducing film. To verify the practicability of the long-chain film for drag reduction of watercraft, the properties of long-chain film such as water resistance, drag reduction effect and effective acting time were researched. The results show that the long-chain film can keep the surface smooth and undamaged after being washed for a long time, and keep a large number of polyacrylamide molecules fixing to the film surface. The long-chain film has significant drag reduction effect in the flow velocity range between 3.6~10m/s, and the average drag reduction efficiency reaches 9.1%, while the effective drag reduction time exceeds 3h, so that the long-chain film has the ability of prolonged drag reduction.