Thermodynamic Prediction
A three-coordinate mathematical model estimates the ability of a solvent to dissolve a specific polymer matrix. Within the scope of electronics recycling and laboratory analysis, hansen solubility parameters allow engineers to predict which organic solvents will dissolve the epoxy resins of printed boards without the need for extensive trial-and-error testing. This model divides the total cohesive energy of a liquid into three distinct components representing dispersion forces, polar forces, hydrogen bonding, and other intermolecular forces.
Solvent Selection
Effective extraction of restricted phthalates from cured solder masks and board laminates requires solvents that match the cohesion energy of the polymer. When the distance between the parameters of the solvent and the polymer is small, the solvent swells or dissolves the resin, which releases the entrapped chemical analytes. This approach enables laboratory technicians to select safe and efficient solvents like tetrahydrofuran rather than relying on hazardous chlorinated alternatives.
Solvent mixtures can also be formulated to target specific board coatings, optimizing the extraction process while minimizing solvent waste and extraction time during RoHS verification runs.
Boundary Condition
The applicability of these parameter values is restricted to non-ionic, organic interactions where physical dissolution is the primary mechanism of action. It cannot predict chemical degradation, acid-base reactions, or the dissolution of highly cross-linked thermosetting resins that undergo chemical decomposition rather than physical swelling.
