Dynamix Equipment for Mixing Polymers
Polymers are made up of long chains that have a wide range of properties. Mixing Polymers with EvenMix together creates materials with properties that are somewhere in between those of the two individual polymers. These mixtures are called blends and can be either miscible or immiscible. Immiscible polymer combinations are multiphase systems, and the morphology of the two phases plays an important role in their final material properties. Immiscible blends can be stabilized by adding so-called compatibilizers.
Compatibilizers have hydrophobic and hydrophilic regions that can be aligned with the interacting polymer surfaces at the interface. This decreases interfacial tension, improving the compatibility of the blend and reducing the tendency to form large particles that would cause phase separation. Achieving the correct balance between polymer blending techniques and chemical methods is key to producing high-quality materials that meet customer specifications.
Whether you are mixing polymers, color concentrates or additives, EvenMix has the mixers you need to achieve the right results. Having the right equipment to mix chemicals and polymers can prevent stringers and fisheyes.
The goal of mixing is to get your product as close to spec as possible, while also making sure the mixture stays in spec through the entire manufacturing process. This is especially critical if you are working with a water treatment application. Polymers can settle and stratify over time, causing problems in the water treatment process.
To keep your water treatment system running smoothly, you need to be able to quickly and accurately mix the polymers that are needed for each stage of the process. Whether you are dealing with dry powders or liquid emulsions, EvenMix has the mixing equipment you need to make sure your polymer blends are mixed to spec every step of the way.
In addition to rheological properties, another important property of polymer blends is their stability. One important way to measure the stability of a polymer mixture is by looking at its critical solution temperature (UCST or LCST). Figure 5 shows experimental and modelled UCST or LCST data for some simple immiscible blends: PS/PMMA and PS/poly(ethylene-propylene copolymer) (PEP).
While comparing the UCST and LCST data from both figures, it is clear that the theory is accurate in its predictions, and the discrepancy between experiment and theory is due mainly to the fact that the FH description of mixing neglects the effect of volume changes on the interactions, and therefore underestimates the enthalpy of mixing. To take into account the interaction between polymer volumes, a more detailed thermodynamic model is needed to accurately predict the enthalpy of mixing. Such a model will take into account the interactions between the two polymer phases, the morphology of the blended system and the morphology of the immiscible component. It is hoped that further development of this type of theoretical model will yield insight which applies across a broad range of systems, and that it will improve the accuracy with which we can predict the UCST or LCST of polymer blends.