Graft copolymerization of vinyl monomers on modified cottons, XXI. Cu⁺⁺/hydrazine hydrate redox system induced grafting of methyl methacrylate on periodate oxidized cellulose

Abstract

Periodate oxidized cellulose was grafted with methyl methacrylate using hydrazine hydrate in presence and absence of Cu++. The grafting reaction was favoured in presence of Cu++ and it was advantageous to treat first the cellulose material with copper sulphate solution rather than to incorporate it in the polymerization system. The graft yields depended upon the concentrations of copper sulphate and hydrazine hydrate, pH, temperature, and time of polymerization as well as degree of oxidation of cellulose. There were optimal concentrations of copper sulphate (6–8 mmol/l) and hydrazine hydrate (2 mmol/l). A polymerization medium of pH 6 and a temperature of 60°C constituted to optimal pH and temperature for grafting. Oxidized cellulose proved to be more amenable to grafting as compared with unoxidized cellulose and the magnitude of grafting relied on the degree of oxidation. A tentative mechanism was also suggested for grafting of cellulose substrates with a vinyl monomer using a Cu++‐hydrazine hydrate redox system.

Dependence of the dyeability of modified cotton on the substituents and the nature of the dye

“…Similarly, cotton cellulose bearing acrylonitrile moieties in the form of a cyanoethyl group, and in the form of polyacrylonitrile, can be prepared through cyanoethylation [14] and grafting [16] respectively. On the other hand, introduction of carboxyl-containing moieties in the molecular structure of cotton cellulose could be effected via carboxymethylation [15] and grafting of cotton cellulose with acrylic acid [16].…”

“…Direct dye [16] The dye solutions were prepared containing 1% dye and 0.5% sodium sulphate. The dyeing bath was heated to 70 °C and held constant at this temperature.…”

“…Reactive dye [16] The dye solutions were prepared containing 1% dye, 2% sodium carbonate and 6% common salt. The temperature of the dyebath was raised to 90 °C for 30 min, then lowered to 70 °C and kept constant.…”

“…Basic dye [16] The dye solutions were prepared containing 2% dye or 1% acetic acid. The dyebath was adjusted to 50 °C.…”

Synthesis and Characterization of Poly(Acrylic Acid) and Poly(Glycidyl Methacrylate) Chitosan Graft Copolymers and Their Application to Cotton Fabric

“…In addition, the Br 2 molecules liberated at higher bromate concentrations [Eq. (7)] may also contribute to the oxidation of chitosan with subsequent degradation of the chitosan macromolecules [17][18][19][20][21][22] .…”