Water content carboxymethyl cellulose

Commercial bakeries and doughnut shops normally use a system that extrudes a batter from a reservoir directly into the deep fat fryer (Figure 5). In such a system the rheology of the batter is vitally important. The batter must flow and spread as needed. The major influence on the batter viscosity is the water content, which is around 70% of the flour or around 40% of the dry mix. Various gums are sometimes added to the dry mix to bind water, reduce fat absorption, and control the viscosity. Examples of these gums are guar gum, locust bean gum and carboxymethyl cellulose. 

A direct relation between the polymer foams density (respectively, the expansion ratio) and the oligomer content in it has been established [114], Addition of water soluble polymers (polyvinyl alcohol, carboxymethyl cellulose, etc.) led to a reduction in resin consumption without deteriorating the quality of the solid foam obtained. Polymer foams of density 5-7 kg m3 were produced when the oligomer consumption was not more than 15-20% with respect to the solution volume. 

The carboxymethylation of cellulose with sodium chloroacetate in an aqueous system generally showed that the 2-OH group was more reactive than the 6-OH group, whereas the 3-OH was the least reactive. A low water content medium resulted in a relatively more uniform reactivity than a high water content reaction [202]. Similarly, carboxymethylation in a nonaqueous system (SO2-DEA-DMSO) [79] resulted in a more uniform reaction and a higher reactivity of the 6-OH group as compared to an aqueous reaction. Interestingly, carboxymethylation with sodium iodoacetate substantially enhanced the reactivity of the 3-OH, which was found to be most reactive under this condition. 

The raw materials are cotton linters, soft wood pulp or dissolving pulp. They must be high in alpha - cellulose content, free of metals and uniformly absorb water and the NaOH solution. The other starting materials include alkylene oxides and alkyl chlorides for the preparation of nonionic cellulose ethers and sodium monochloroacetate for anionic types such as sodium carboxymethyl cellulose. 

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