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The vinylsulfone group reacts with the nucleophilic functional groups of the fibers by Michael addition to form a covalent ether bond: Reaction of vinyl sulfone compounds with hydroxyl groups of cellulose (HO-CELL) An unfavorable side reaction in the dyeing process is the conversion of the vinylsulfone group to the 2-(hydroxy)ethylsulfonyl ...
The hydroxyl groups (−OH) of cellulose can be partially or fully reacted with various reagents to afford derivatives with useful properties like mainly cellulose esters and cellulose ethers (−OR). In principle, although not always in current industrial practice, cellulosic polymers are renewable resources. Ester derivatives include:
N 3 C 3 Cl 2 (NHdye) + HO-cellulose → N 3 C 3 Cl(NHdye)(O-cellulose) + HCl. The fixation process is conducted in a buffered alkaline dye bath. [citation needed] An alternative fixation process that is more dominant commercially is the vinylsulfonyl group. Like the chlorotriazines, this functional group adds to the hydroxyl groups of cellulose.
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula −OH and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry , alcohols and carboxylic acids contain one or more hydroxy groups.
HPC is an ether of cellulose in which some of the hydroxyl groups in the repeating glucose units have been hydroxypropylated forming -OCH 2 CH(OH)CH 3 groups using propylene oxide. The average number of substituted hydroxyl groups per glucose unit is referred to as the degree of substitution (DS). Complete substitution would provide a DS of 3.
Another important triazine is cyanuric chloride (2,4,6-trichloro-1,3,5-triazine). Chlorine-substituted triazines are components of reactive dyes. [2] These compounds react through a chlorine group with hydroxyl groups present in cellulose fibres in nucleophilic substitution, the other triazine positions contain chromophores.
In chemistry, hydroxylation refers to the installation of a hydroxyl group (−OH) into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility. Hydroxylation of a hydrocarbon is an oxidation, thus a step in degradation.
In terms of their mode of action, the anhydride is proposed to react with the hydroxyl groups on the cellulose, forming an ester. The alkenyl side-chain modifies the surface properties of the paper product. [2] The application is similar to that for alkyl ketene dimers. In the United States alkenylsuccinic anhydrides are the preferred paper ...