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Polysaccharide-Based Polymers in Cosmetics
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
In one application, EHEC plays a role in the delivery of therapeutics to the eye (167). When an EHEC solution with a particular active is administered to the ocular surface, the salts and warmth of the eye cause the polysaccharide solution to thicken or gel. This reduces the cleansing effect of natural tearing and enhances the drug’s residence time on the ocular surface. Nitrocellulose. Nitrocellulose is one of the oldest-known modified cellulose derivatives (170). It is manufactured by treating cellulose pulp with a combination of nitric and sulfuric acids. Treatment with this acid combination creates nitrate esters on the cellulose hydroxyl groups (Fig. 39). Levels of commercial nitration are extremely critical because cellulose, nitrated to levels greater than 12% nitrogen, is commercially used as an explosive. Between 11 and 12% nitrogen, cellulose is soluble in various organics including many alcohols, ketones, and aromatic solvents.
Chemicals from Non-hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
In organic chemistry, nitric acid is the primary reagent used for nitration—the addition of a nitro (–NO2) group to an organic molecule. While some resulting nitro-compounds are sensitive to shock and thermal effects, such as trinitrotoluene (TNT), some are sufficiently stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agent.
Complexes of copper(I) with aromatic compounds facilitate selective electrophilic aromatic substitution
Published in Journal of Coordination Chemistry, 2018
Magal Saphier, Inna Levitsky, Alexandra Masarwa, Oshra Saphier
Nitration of aromatic compounds is an industrially consequential reaction as the nitrated products are important intermediates for fine chemicals and pharmaceuticals. Generally, nitration reactions are not selective and are the cause of environmental concerns regarding the disposal of the large excess of mixed acids employed in these processes.