The polymerization methods of drag reducer mainly include solution polymerization and bulk polymerization.

The bulk polymerization method has a low conversion rate at the initial stage of polymerization. The viscosity of the system is not large and the heat dissipation is easy. But after the conversion rate is increased, the viscosity of the system increases, resulting in gel effect. If not heat dissipated in time, it is easy to cause explosive polymerization, but because of the high conversion rate of bulk polymerization, it is widely used. Zhao Mengqi et al. Synthesized ultra high molecular weight polymer by bulk polymerization with a small amount of 1,5-Hexadiene crosslinking agent. The shear stability of the product and the relative molecular weight of the product were improved, but the drag reduction rate of the polymer was only 39.1%. Bulk polymerization is the reaction of monomer and catalyst system under certain conditions without solvent. Its characteristics are: pure product, no need to duplicate, product separation operation, product direct powder, modulation agent use. However, the reaction heat of this method is not easy to dissipate, and the reaction is easy to generate flying temperature phenomenon. Therefore, in the experimental equipment, the stirring and temperature control system has become the key to production.

The solution polymerization method can discharge the heat generated in the polymerization process in time to avoid local overheating and reduce the gel effect. However, due to the dilution of solvent, the conversion of monomer is low, the separation and recovery costs of monomer and solvent are high, and the viscosity of polymerization system is high, so it is difficult to be used in the field. By improving the device and adding some additives, the solution polymerization method has made some achievements.