Scavengers, moisture

The intermediate phosphite employed in this synthesis was prepared by condensation of duly protected sialic acid with the nucleosidyl phospho-roamidite in the presence of N-PhIMT. Oxidation by TBHP and deprotection according to standard procedures gave the cytidine-S -monophospho-iST-ace-tylneuraminic acid. This synthetic route is claimed to have advantages over procedures published earlier [26]. The same group demonstrated the importance of 3 A and 4 A molecular sieves as moisture scavengers in the reaction of nucleoside phosphoroamidite with a nucleotide. This approach should be likely to find application in the synthesis of biophosphates outside nucleotide chemistry. 

Williams RO III, Hu C. Investigation of moisture scavengers in pressurized metered-dose inhalers. STP Pharma Sci 2000 10(3) 243-250. 

The polymerization of cyclopropanone is initiated °) by traces of water and is inhibited 15> by moisture scavengers such as acetyl chloride. The terminal groups are apparently hemiketal units since a,co-diacetoxy-poly(oxycyclopropylidenes) 85 are isolated from a mixture of cyclopropanone hydrate, diazomethane and excess ketene. 80>... 

Potassium carbonate The moisture scavenging effect of potassium carbonate in effervescent tablets has been investigated. ... 

The presence of excipients in a formulation can influence product stability. The conceptually appealing strategy of including a moisture scavenger in a formulation is based on this. In glucose-containing systems, it was demonstrated that liquid and solid... 

The two extreme cases are zeolite (the smallest pore size) and diatomaceous earth (the largest volume of pores). Zeolites are manufactured with predesigned pore sizes to match the sizes of molecules which can fit into these pores and become absorbed into the pore area. Applications for zeolites include moisture scavenging and selective absorption of various chemical components of mixtures. Diatomaceous earth at the other end of the scale is not selective at all. The large number of pores allows it to absorb 190-600% of its own mass. Applications include absorption of liquids and regulation of rheological properties. The mechanism of rheological control is simple. When the liquid and diatomaceous earth is... 

The mechanism of cure has an important influence on the filler choice. In reactive systems such as polyurethanes, water present in formulation adversely affects sealant stability (shelf-life) which imposes the additional selection criterion of water content. If water is present in the filler it must be removed by additional operations either by an expensive drying process or through the use of chemical moisture scavengers which is also an expensive approach. 

Polymers of oxazolidines have been used for moisture scavenging polyurethane coatings <93MI 304-03). 

Uses Moisture scavenger for use in urethane coatings, sealants and elastomers... 

Uses Moisture scavenger for use in urethane coatings, sealants and elastomers eliminates moisture from solvents, polyols and pigment grinds without adversely affecting film props. 

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