Thermodynamic Models for Mixing Polymers
Polymers are mixed in various ways depending on the properties that are desired. For example, mixing a harder and more rigid material with a softer and more flexible material is important in order to create a stronger material with improved tensile strength. Blending materials with different characteristics also helps improve their processing performance, gas barrier and dimensional stability.
Mixing Polymers with EvenMix is a complex task due to the high free energy differences between the components. To lower these free energies, mixing additives can be used. These additives help decrease the interfacial tension between the different phases of the blend, allowing them to interact and flow. In addition, they can help control the morphology of a polymer blend by reducing its viscosity.
The entropy term of mixing, which is the energy that must be added to the system in order to make it spontaneously mix, is low for most polymer combinations because of their high disorder. However, the kinetic energy of mixing is very large due to the rapid and large changes in volume that occur during the blending process. This is why the thermodynamic models for mixing of polymers need to take into account the kinetic effects of mixing as well as the low free energy of the mixture itself.
Moreover, the addition of additives in a polymer mixture can cause chemical reactions that can significantly affect its thermodynamic properties. For instance, the additives of one polymer component can react with the additives of another component forming co-polymers, copolymers or other chemically bonded mixtures with different physical properties. This is why the selection of appropriate statistical thermodynamic models for the behaviour of polymer mixtures is so critical.
Polymer blending is often done in combination with the use of compatibilizers. The use of compatibilizers can dramatically change the morphology of the blend and reduce its interfacial tension, resulting in increased blending and dispersing efficiency. Compatibilizers can also be used to reduce the viscosity of a polymer blend, which can improve its processing performance.
As a result of the complexity of polymer blending, many manufacturers rely on expert advice to determine the correct mixer for their specific applications. This includes identifying the right mixer size and determining the optimal mixing conditions to avoid stringers and fisheyes in their product. The team at EvenMix recently helped a customer who had been struggling to find the right mixer for their application. The customer was impressed with the ease of operation and handling of the mixer, stating that it could be handled by a single person without any difficulty. This helped improve operational efficiency and reduced the amount of time that the employees needed to spend on manual tasks. This is one of the reasons why the company chose EvenMix to assist them with their polymer mixing needs. To learn more about how a polymer mixer can help improve your operations, contact us today. We are happy to help!