We recently developed a new dispersant which can decrease the viscosity of concentrated polyethylene (PE) particle dispersions significantly. This dispersant is a block copolymer constructed with side chain crystalline monomers and solvent compatible monomers (Side Chain Crystalline Block Copolymer : SCCBC). Also the viscosity of this dispersion shows reversible temperature dependence that the viscosity increases with increasing temperature up to almost the original value of the dispersion without the dispersant. This phenomenon is named as “Thermal Rheology” and the fluid is named as “Thermal Rheological (TR) Fluid”. In the previous report, we found this TR Fluid effect depends on the randomness of the copolymer and solvent species qualitatively.
In this investigation we researched about copolymer molecular composition and weight dependence on the TR Fluid effects. We also researched about deformation mode dependence. From this research, the TR Fluid effects strongly depend on the molecular weight, especially on the molecular weight of side chain crystalline composition. Also the TR Fluid effects are significant in low shear rate region and dynamic deformation mode.