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In addition, chemical compatibility refers to the container material being acceptable to store the chemical or for a tool or object that comes in contact with a chemical to not degrade. For example, when stirring a chemical, the stirrer must be stable in the chemical that is being stirred. Many companies publish chemical resistance charts.
Another application of polymer solutions includes the manufacture of fibers by wet or dry spinning or plastic films. Disadvantages of solution polymerization are decrease of monomer and initiator concentration leading to reduction of reaction rate, lower volume utilization of reactor, additional cost of the process related to solvent recycling ...
In polymer chemistry, compatibilization is the addition of a substance to an immiscible blend of polymers that will increase their stability. Polymer blends are typically described by coarse, unstable phase morphologies; this results in poor mechanical properties. Compatibilizing the system will make a more stable and better blended phase ...
The phase behavior of polymer solutions is an important property involved in the development and design of most polymer-related processes. Partially miscible polymer solutions often exhibit two solubility boundaries, the upper critical solution temperature (UCST) and the LCST, both of which depend on the molar mass and the pressure. At ...
Flory–Huggins solution theory is a lattice model of the thermodynamics of polymer solutions which takes account of the great dissimilarity in molecular sizes in adapting the usual expression for the entropy of mixing. The result is an equation for the Gibbs free energy change for mixing a polymer with a solvent. Although it makes simplifying ...
B reflects the energy of binary interactions between solvent molecules and segments of polymer chain. When B > 0, the solvent is "good," and when B < 0, the solvent is "poor". For a theta solvent, the second virial coefficient is zero because the excess chemical potential is zero; otherwise it would fall outside the definition of a theta solvent.
Molecular structure of Kevlar Molecular structure of the LCP Vectran [5]. Liquid crystallinity in polymers may occur either by dissolving a polymer in a solvent (lyotropic liquid-crystal polymers) or by heating a polymer above its glass or melting transition point (thermotropic liquid-crystal polymers). [6]
Some polymer solutions also have a lower critical solution temperature (LCST) or lower bound to a temperature range of partial miscibility. As shown in the diagram, for polymer solutions the LCST is higher than the UCST, so that there is a temperature interval of complete miscibility, with partial miscibility at both higher and lower temperatures.