MECHANICAL-PROPERTIES OF SILK FIBERS TREATED WITH METHACRYLAMIDE

Silk fibers were treated with methacrylamide (MAA), and changes in the mechanical properties of the silk fibers were investigated. The break ing load of the silk fibers was almost unchanged, whereas rigidity was markedly increased by the methylmethacrylate (MAA) treatment. Elongat ion at break of the silk fibers decreased significantly when the fiber s were treated with MAA up to polymer add-on (ca. 300%). The cross-sec tional area of the MAA-treated silk fiber was given by the addition of the cross-sectional area of the original silk fiber and that of the M AA polymer. The Young's modulus of MAA-treated silk fibers increased l inearly with increasing volume fractions of fiber in MAA-grafted silk fibers. The Young's modulus of the MAA polymer in the MAA-treated silk fibers was estimated by extrapolating the relation between Young's mo duli and volume fractions of fiber to the zero volume fraction of fibe r. The Young's modulus of the MAA polymer in the MAA-treated silk fibe rs was larger than the sonic modulus measured for an MAA polymer plate . (C) 1996 John Wiley & Sons, Inc.