Chemical Composition of Silk Fiber, Cotton Fiber & Wool Fiber https://www.pandasilk.com/ Silk is a natural protein fiber, composed mainly of fibroin and is produced by certain insect larvae to form cocoons. Silk (78% protein) is much stiffer than wool in spite of both being proteins made from amino acids chains. Silk emitted by the silkworm consists of two main proteins, sericin and fibroin, fibroin being the structural center of the silk, and serecin being the sticky material surrounding it. Fibroin is largely made up of the amino acids Gly-Ser-Gly-Ala-Gly-Ala and forms beta pleated sheets, β-keratin. R = H, glycine; R = CH3,
alanine; R = CH2OH, serine
Chemical Composition Of Silk • • • • •
Fibroin: Sericin: Fat and Wax: Ash of Silk Fibroin: Mineral Salt:
75% 22.5% 1.5% 0.5% 0.5%
https://www.pandasilk.com/properties-uses-of-silk-fiber-silk-fabric/ Cotton and wool chemical composition attached too:
Chemical Composition of Cotton Fiber • • • • • • • •
Cellulose Protein Ash Pectin Oil, Fat and Wax Sugar Pigment Others
94% 1.3% 1.2% 1.2% 0.6% 0.3% trace 1.4%
Chemical Composition of Wool Fiber • • • • •
Keratin Dirt 26% Suint Fat Mineral matter
33%
28% 12% 1%