Abstract
Cotton fibers have been either dihydroxypropylated (DHP-) or carboxymethylated (CM-) to enhance the water absorbency (WA) without changing the handling (Fuh-Ai) and the mechanical properties of cotton fibers. The treatments were conducted topochemically in different ways, namely, for the whole of fiber and for only the inner of fiber. Fibers thus chemically modified were subjected to several tests for judging their end-uses performances. The effects of the chemical species and the topology of introduced hydrophilic residues upon the WA, the moisture regain and the rate of water regain etc. are discussed. Some of the important findings were: (1) the WA-value of these samples depends uniquely on the number of hydrophilic residues (the degree of substitution: DS), independent of their chemical species and topology; (2) when sodium salt in the CM-samples is converted to Ca salt, the WAis decreased in the order of Na-salt>Ca-salt>“Acidic”. However, the“Acidic”still exhibits a sufficiently high WAcomparable with that of a DHP-sample having a DS-value higher by ten times than that of a CM-sample; (3) the water absorption bahavior by modified samples does not differ for vapor and liquid, and is independent of the chemical species and the topology of introduced hydrophilic groups.
