Poly primary alcohol

The viscosity of the latex can also be dependent on pH. In the case of some latices, lowering the pH with a weak acid such as glycine is an effective method for raising the viscosity without destabilising the system. Latices made with poly(vinyl alcohol) as the primary emulsifier can be thickened by increasing the pH with a strong alkaU. 

In the suspension polymerization of PVC, droplets of monomer 30—150 p.m in diameter are dispersed in water by agitation. A thin membrane is formed at the water—monomer interface by dispersants such as poly(vinyl alcohol) or methyl cellulose. This membrane, isolated by dissolving the PVC in tetrahydrofuran and measured at 0.01—0.02-p.m thick, has been found to be a graft copolymer of polyvinyl chloride and poly(vinyl alcohol) (4,5). Early in the polymerization, particles of PVC deposit onto the membrane from both the monomer and the water sides, forming a skin 0.5—5-p.m thick that can be observed on grains sectioned after polymerization (4,6). Primary particles, 1 p.m in diameter, deposit onto the membrane from the monomer side (Pig. 1), whereas water-phase polymer, 0.1 p.m in diameter, deposits onto the skin from the water side of the membrane (Pig. 2) (4). These domain-sized water-phase particles may be one source of the observed domain stmcture (7). 

Some materials such as water, alcohols, carboxylic acids and primary and secondary amines may be able to act simultaneously as proton donors and acceptors. Cellulose and poly(vinyl alcohol) are two polymers which also function in this way. 

The final example in this section is the synthesis of a tristetrahydrofuran 2-606 described by the group of Rychnovsky [313]. Here, the tris(sulfate) 2-605 was converted into 2-606 by simply heating it in a mixture of MeCN and H20 (Scheme 2.138). The domino reaction is most likely initiated by deprotection of the primary alcohol, which then attacks the adjacent sulfonate unit in a SN2-type manner to afford the first furan moiety. Under the reaction conditions the formed acyclic sulfate is hydrolyzed affording a free secondary alcohol which then attacks the next adjacent cyclic sulfate unit. Overall, the SN2/hydrolyzation sequence proceeds three times to finally provide the poly(tetrahydrofuran) 2-606 as a single isomer in 93 % yield. 

The selective separation of water from aqueous solutions of isopropanol or the dehydration of isopropanol can be carried out with different membranes, which contain polar groups, either in the backbone or as pendent moieties. For the dehydration of such a mixture, poly(vinyl alcohol) (PVA) and PVA-based membranes have been used extensively. PVA is the primary material from which the commercial membranes are fabricated and has been studied intensively for pervaporation because of its excellent film forming, high hydrophilicity due to -OH groups as pendant moieties, and chemical-resistant properties. On the contrary, PVA has poor stability at higher water concentrations, and hence selectivity decreases remarkably. 

Nonwovens are widely utilized as separators for several types of batteries. Lightweight, wet laid nonwovens made from cellulose, poly (vinyl alcohol), and other fibers have achieved considerable success as separators for popular primary alkaline cells of various sizes. The key nonwoven attributes include consistently uniform basis weight, thickness, porosity and resistance to degradation by electrolytes. Nonwovens are also successfully employed as separators in NiCd s. 

For battery separators, regenerated cellulose is placed on the surface of nonwoven so that the nonwoven is available to promote the wicking of the electrolyte. The nonwovens should not allow the penetration of viscose into itself. Suitable nonwovens are made from polypropylene, poly(vinyl alcohol), and hardwood hemps. Regenerated cellulose films are commonly used in alkaline manganese cells, both primary and secondary, in NiCd industrial batteries, as well as in silver—zinc batteries. 

The direct electrochemical oxidation of aliphatic alcohols occurs at potentials which are much more positive than 2.0 V w. SCE. Therefore, the indirect electrolysis plays a very important role in this case. Using KI or NaBr as redox catalysts those oxidations can be performed already at 0.6 V vs. SCE. Primary alcohols are transformed to esters while secondary alcohols yield ketones In the case of KI, the iodo cation is supposed to be the active species. Using the polymer bound mediator poly-4-vinyl-pyridine hydrobromide, it is possible to oxidize secondary hydroxyl groups selectively in the presence of primary ones (Table 4, No. 40) The double mediator system RuOJCU, already mentioned above (Eq. (29)), can also be used effectively Another double mediator system... 

The lower members of the homologous series of 1. Alcohols 2. Aldehydes 3. Ketones 4. Acids 5. Esters 6. Phenols 7. Anhydrides 8. Amines 9. Nitriles 10. Polyhydroxy phenols 1. Polybasic acids and hydro-oxy acids. 2. Glycols, poly-hydric alcohols, polyhydroxy aldehydes and ketones (sugars) 3. Some amides, ammo acids, di-and polyamino compounds, amino alcohols 4. Sulphonic acids 5. Sulphinic acids 6. Salts 1. Acids 2. Phenols 3. Imides 4. Some primary and secondary nitro compounds oximes 5. Mercaptans and thiophenols 6. Sulphonic acids, sulphinic acids, sulphuric acids, and sul-phonamides 7. Some diketones and (3-keto esters 1. Primary amines 2. Secondary aliphatic and aryl-alkyl amines 3. Aliphatic and some aryl-alkyl tertiary amines 4. Hydrazines 1. Unsaturated hydrocarbons 2. Some poly-alkylated aromatic hydrocarbons 3. Alcohols 4. Aldehydes 5. Ketones 6. Esters 7. Anhydrides 8. Ethers and acetals 9. Lactones 10. Acyl halides 1. Saturated aliphatic hydrocarbons Cyclic paraffin hydrocarbons 3. Aromatic hydrocarbons 4. Halogen derivatives of 1, 2 and 3 5. Diaryl ethers 1. Nitro compounds (tertiary) 2. Amides and derivatives of aldehydes and ketones 3. Nitriles 4. Negatively substituted amines 5. Nitroso, azo, hy-drazo, and other intermediate reduction products of nitro com-pounds 6. Sulphones, sul-phonamides of secondary amines, sulphides, sulphates and other Sulphur compounds... 

An eco-friendly oxidation of alcohols under an oxygen atmosphere using catalytic amounts of [bis(acetoxy)iodo]benzene-TEMPO-KN02 has been reported. The use of a catalytic amount of poly[4-(bis(acetoxy)iodo)]styrene allowed the successful recycling of this catalytic component. The protocol can be used to promote the oxidation of different kinds of alcohols in the presence of other functional groups and also in the oxidation of primary benzylic alcohols in the presence of secondary and aliphatic ones. Primary alcohols can be oxidized to the corresponding aldehydes without any noticeable overoxidation to the carboxylic acids.269... 

Hydroboration of alkenes1 (15, 91). The Rh(I)-catalyzed hydroboration provides a highly diastereoselective reaction in a synthesis of a poly ether antibiotic. Thus the derivative (1) of an acyclic allylic alcohol is converted to the primary alcohol 2 by hydroboration with catecholborane (CB) catalyzed by ClRh[P(C6H5)3]3 with 94 6 selectivity. Note that hydroboration of 1 with disiamylborane (12, 484) proceeds with the opposite selectivity at Cio (8 92). 

Reductions of carboxylic acid chlorides using NaBH4 in ethereal solvents (dioxane, DME, THF, poly(ethylene glycol) rapidly provide primary alcohols. Reductions in poly(ethylene glycol)- ... 

When poly-hydroxy alcohols are oxidized the first product is a compound in which one of the alcohol groups has been oxidized either to aldehyde or to ketone depending on whether the alcohol group is primary or secondary. 

Ketone Alcohols.—From the higher poly-hydroxy alcohols however, which contain both primary and secondary alcohol groups we obtain both aldehyde alcohols and ketone alcohols. Glycerol or propantriol thus yields the following ... 

From Poly-hydroxy Alcohols.—4. Poly-hydroxy alcohols by oxidation, yield poly-hydroxy acids. In this case, of course, only primary alcohol groups, ( —CH2OH), can yield carboxyl and these groups must, necessarily, be at the end of the carbon chain. The oxidation must be mild so that only one alcoholic group shall be affected. 

By the three preceding reactions and by the formation of carbohydrates by the oxidation of poly-hydroxy alcohols, carbohydrates are poly-hydroxy alcohols in which one alcohol group is oxidized to aldehyde (primary alcohol group at the end of the chain), or to ketone (secondary alcohol group). 

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