Structures of wool fibers Intermolecular bonding Cross-linking: 2 cystine amino acids one on each of the two adjacent chains form a cystine link a covalent bond(s-s bond), increasing strength and elasticity lonic bond: salt linkage formed when two amino acids are in close proximity: responsible for reacting with acid dyes Hydrogen bonds: between amide groups but have relatively low density due to more amorphous phase and packing difficultiesStructures of wool fibers Intermolecular bonding – Cross-linking: 2 cystine amino acids one on each of the two adjacent chains form a cystine link, a covalent bond (S-S bond), increasing strength and elasticity. – Ionic bond: salt linkage formed when two amino acids are in close proximity: responsible for reacting with acid dyes. – Hydrogen bonds: between amide groups but have relatively low density due to more amorphous phase and packing difficulties