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Such charts are particularly important for polymers [4] as they are often not compatible with common chemical reagents; this may even depend on how the polymers have been processed. [5] For example, 3-D printing polymer tools used for chemical experiments must be chosen to ensure chemical compatibility with care. [6]
An advantage to solvent bonding versus other polymer joining methods is that bonding generally occurs below the glass transition temperature of the polymer. [2] [3] Solvent bonding differs from adhesive bonding, because the solvent does not become a permanent addition to the joined substrate. [4] Solvent bonding differs from other plastic ...
Mixture of polymers and solvent on a lattice. 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.
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.
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.
The nearer two molecules are in this three-dimensional space, the more likely they are to dissolve into each other. To determine if the parameters of two molecules (usually a solvent and a polymer) are within range, a value called interaction radius is given to the substance being dissolved. This value determines the radius of the sphere in ...
Polymer solutions are solutions containing dissolved polymers. [1] These may be liquid solutions (e.g. in aqueous solution ), or solid solutions (e.g. a substance which has been plasticized). [ 2 ]
Liquid-crystal polymers are present in melted/liquid or solid form. [7] In solid form, the main example of lyotropic LCPs is the commercial aramid known as Kevlar. The chemical structure of this aramid consists of linearly substituted aromatic rings linked by amide groups.