Some properties of polymers can be enhanced by mixing with another polymer.
When two or more polymers are tightly mixed in a continuous solid product, the composition is usually referred to as a polymer blend or polymer blend.
Depending on the degree of mixing or immiscibility, this blend may resemble random copolymers, block copolymers, or graft copolymers, or may exhibit microscopic or macroscopic heterogeneous phase separation in multiphase systems. The viscosity method is simple and provides very useful information for studying the relationship between the properties of dilute solutions and the structure of polymer blends.
The basic idea of using viscosity as a parameter is that the compatibility determination of polymer blending lies in the fact that the repulsive interaction of polymer coils in solution may lead to shrinkage, resulting in the viscosity of the polymer mixture being lower than the value of pure components calculated from the hypothetical additive method of viscosity.
This study attempted to blend polypropylene glycol ppg4000 with polyethylene glycol PEG 4000 in a solvent of 304K in 1,4-dioxane at a concentration of 1%. The ratio of the blend is: 0:1, 0.2:0.8, 0.4:0.6, 0.5:0.5, 0.6:0.4, 0.8:0.2, 1:0.
The relative viscosity of the blend was measured, and the results showed that the relative viscosity of the blend was non-linear and incompatible. The mixing properties of the blend were further determined using additive law, logarithmic additive law, and free volume additive law. All experimental values showed negative deviations, which is a characteristic of immiscible blends. The miscibility of the blend was further confirmed through techniques such as density, ultrasonic velocity, and refractive index. This mixture exhibits immiscibility.