Treatments in highly polar solvents, such as dimethyl formamide, dimethyl acet amide, and dimethyl sulfoxide, under suitable conditions have been found to improve the dyeability of Nomex® yam so that it can be dyed under atmospheric conditions in a reasonable length of time without the aid of a carrier. Essentially, these solvents provide chemical energy to the yam, permitting rearrangements of the polymer chains through breakage and reformation of interchain hydrogen bonding. The changes in dyeability may be attributed to orientation changes or to microvoid formation occurring in the fiber structure during treatment.
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References
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2.
Cook, F.L., and Kleissler, B.R., Effect of Auxiliary Solvents in STX® Coloration of Aramids and PBI with Cationic Dyes, in "Book of Papers, AATCC National Technical Conference," New Orleans, Louisiana, October 5-7, 1983, pp. 314-326; and private communications.
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