Thermal Behavior and Melting of Non-Ionic Dye Solids
Abstract
The physico-thermal process occurring in pure disperse and vat dye solids on heating up to the melting or decomposition point of the dye has been examined. Differential scanning calorimetry has been used to detect and characterize solid to solid and solid to liquid phase changes by determining heats and entropies of transition and melting. The existence of polymorphs and associated thermal transitions has been shown by hot-stage microscopy, photomicrography, and X-ray powder diagrams. The calorimetric method has also been used to determine the temperature dependence of the heat capacity of the dyes. In those dyes exhibiting a solid to liquid phase change, evidence of pre- melting or premonitory effects are observed from which the activation energy of disorder formation in the crystal has been found. With vat dyes, which do not melt within the temperature range considered, there is evidence for an increase in lattice perfection at high temperature without change in lattice structure. The results may be usefully applied to dyeing processes both under aqueous and anhydrous conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- AD0727677
Entities
People
- Francis Jones
- Leonard J. Flores
Organizations
- United States Army Soldier Systems Center