A Microscopical Survey of Flame-Resistant Cotton Fabrics

Abstract

Three cotton printcloth fabrics treated for flame resistance with THPOH-NHx, oxidized and nonoxidixed, were studied by light microscopy and by transmission (TEM) and scanning (SEM) electron microscopy. Chars of the treated fabrics were also examined. Staining with Acid Blue I and examination by light microscopy provided a semicluantitative assessment of penetration of nonoxidized THPOH-NHa into yarns and fibers, but was less effective with the oxidized sample. SEM observations indicated polymer build-up on fabric surfaces. Deposits of polymer between fibers were usually heavier around the periphery of the yarn. Laundering removed surface deposits but oxidized samples laundered 50 times were still flame resistant, TEM of ultrathin cross sections showed that no major structural change had occurred in the treated fibers. Both SEM and TEM of fiher char sections indicated that the fibers had become shells on burning.Residue patterns left by treated fiber sections after microincineration suggested that the laulymer had completely penetrated the fibers.

Effects of Heat on Cotton, Polyester, and Wool Fibers in Blended Fabrics - A Scanning Electron Microscopy Study

“…Scanning electron microscopy (SEM) provides a means for examination at magnifications great enough to see changes in indi-vidual fiber structures, and has been used to study chars of cotton fabrics that had been treated with various flame retardant (FR) agents [3,4,6,7]. Natural and synthetic fibers respond differently to flame retardants and to heat, and thus have different effects on the resulting char.…”

SEM Studies of the Chars of Flame-Retardant Treated Fabrics

“…The occurrence of the blisters (nodules) can also be seen. Goynes et al [3] have suggested that the bubbles (nodules) observed on the char of fabric treated with THPOH-NH3 finish could be due to the entrapment of decomposition gases in the coating of ' the fused polymer on the fiber surface. Figure 3 represents a situation where the polymer coating has increased to the extent that formation of nodules can occur.…”

“…B Scanning electron microscope (SEM) examinations based on polymeric flame-retardent (FR) finishes have been reported by Goynes et al [3] and Tomioka and co-workers [7]. In these studies the char obtained by burning the fabrics treated with THPOH-NH3 showed the presence of a thick coating, as well as blisters, on the surface.…”

Effect of metallic oxides in polypropylene composites containing melamine phosphate and pentaerythritol

“…The formation of such liquid intermediates, which catalyse the char forming, is supported by Goynes et al through electron microscopic evidence. 17 It is likely that the char forms simultaneously through the respective liquid stages of the melt polymer and the liquid intermediates. Therefore, the observed char structure is a consequence of the chemical reactions of flame retardant additives by physical molten mixing.…”