广东费飘职业故本学院 Guangdong Inatitute of Textile Technology Structures of wool fibers a Submicrostructure Cotex: each cortex cell composed of ◆ macrofibril ■ microfibrils · protofibrils keratin polymer molecules (polypeptide)
Structures of wool fibers ❑ Submicrostructure ◼ Cotex: each cortex cell composed of macrofibrils ◼ microfibrils ▪ protofibrils - keratin polymer molecules (polypeptide)
广东费飘职业故本学院 Guangdong Inatitute of Textile Technology Structures of wool fibers a Keratin polymer: helix of amino acids Structural characteristics 18 different amino acids each with -N-c-c- backbone > a helix: 3 amino acids per turn(right-handed helix) Diversity of amino acids: good for dyeing Polar groups in amino acids hydrophilicity s Cystine amino acid: contains sulfu degradation by moths and beetles Big side groups and spiral molecular configuration hard to be packed well leading to low crystallinity(only 25-30%)
Structures of wool fibers ❑ Keratin polymer: helix of amino acids ◼ Structural characteristics ➢ 18 different amino acids: each with -N-C-Cbackbone ➢ a helix: 3 amino acids per turn (right-handed helix) ➢ Diversity of amino acids: good for dyeing ➢ Polar groups in amino acids: hydrophilicity ➢ Cystine amino acid: contains sulfur: degradation by moths and beetles ➢ Big side groups and spiral molecular configuration: hard to be packed well leading to low crystallinity (only 25-30%)