Structural models of the keratin derivatives. An approach to its solubility and processability

Small-size models of keratin constituent units and products of its decomposition are proposed and computed to i) reproduce the interaction patterns that hold the macromolecule structure and its behavior under different reaction media and physico-chemical conditions; ii) estimate the energy of interactions that support the tridimensional structure of the protein, and consequently, the energy requirements to break it. To create these models and evaluate their performance, quantum-chemical, COSMO, and COSMO-RS calculations were performed. They seem to be capable to support process simulations during the conceptual design and optimization of operations and processes to transform the raw keratin into products of higher added value. Besides, proper analyses using these models demonstrated that the cleavage of the disulfide bonds is the primary condition to break the macromolecule but additionally, the intramolecular H-bond network should be dissociated enabling the intramolecular interaction with the chemicals used to dissolve and regenerate the keratin.