Polyalcohol

Polymerization. Carbon monoxide forms copolymers with ethylene and suitable vinyl compounds. No large-scale uses for the copolymers or their further reaction products such as polyalcohols and polyamines have been found (75). 

Polyalcohols, such as glycerol, sugar, sorbitol, and propylene glycol may prevent denaturation (28). Also substrates or substrate analogues often stabilize by conferring an increased rigidity to the enzyme stmcture. 

Microbiol Stability. Microbial growth is hindered by reducing water activity and adding preservatives. An overview is available (30). Reduction in water activity is typically obtained by including approximately 50% of a polyalcohol such as sorbitol or glycerol. Furthermore, 20% of a salt like NaCl has a pronounced growth inhibiting effect. 

In this case the formation of phenol-alcohols is rapid but their subsequent condensation is slow. Thus there is a tendency for polyalcohols, as well as monoalcohols, to be formed. The resulting polynuclear polyalcohols are of low molecular weight. Liquid resols have an average of less than two benzene rings per molecule, while a solid resol may have only three to four. A typical resol would have the structure shown in Figure 23.12. 

When glucose (Problem 19.72) is treated with NaBH4, reaction occurs to yield sorbitol, a polyalcohol commonly used as a food additive. Show how this reduction occurs. 

Treatment of an aldose or ketose with NaBH4 reduces it to a polyalcohol called an alditol. The reduction occurs by reaction of the open-chain form present in the aldehyde/ketone hemiacetal equilibrium. Although only a small amount of the open-chain form is present at any given time, that small amount is reduced, more is produced by opening of the pyranose form, that additional amount is reduced, and so on, until the entire sample has undergone reaction. 

Polyurethane foams are generally made using a polyalcohol rather than a diol as the monomer, so the polymer has a high amount of three-dimensional cross-linking. The result is a rigid but very light foam suitable for use as thermal insulation in building construction and portable ice chests. 

D-myo-inositol is a six carbon polyalcohol in a ring structure arranged in a chair configuration. 

Conduritols and inositols are cyclic polyalcohols with significant biological activity. The presence of four stereogenic centers in the stmcture of conduritols allows the existence of 10 stereoisomers. Enzymatic methods have been reported for the resolution of racemic mixtures or the desymmetrization of meso-conduritols. For example, Mucor miehei lipase (MML) showed enantiomeric discrimination between all-(R) and all-(S) stereoisomers ofconduritol E tetraacetate (Figure 6.52). Alcoholysis resulted in the removal of the four acetyl groups ofthe all-(R) enantiomer whereas the all-(S) enantiomer was recovered [141]. 

A matching search was made of the data available for two highly polar classes of chemicals — polyamines and polyalcohols — to find the polymer likely to be most resistant to chemical permeation by such highly polar compounds. 

Table II. Polyamines and Polyalcohols Matched by Material (Polymer)...

Polyalcohols have been tested against many different vendor models of three polymers, but only ethylene glycol has been tested against most of them. 

There may be more than one hydroxyl group in an organic molecule. Polyalcohols are widely found in nature as all starchs and sugars are polyalcohols including sucrose (table sugar), and all fats, both vegetable and animal, are derivatives of glycerine. 

The largest single use of maleic anhydride is in the preparation of unsaturated polyester resins. It is first esterihed with a polyalcohol (two or more hydroxyls) and then the double bond is copolymerized (crosslinked) with a vinyl monomer such as styrene to form a rigid structure. Such resins are usually reinforced with hberglass (FRP). Maleic anhydride is also used to make oil additives and agricultural chemicals. 

A corrosion inhibitor with excellent film-forming and film-persistency characteristics is produced by first reacting Cig unsaturated fatty acids with maleic anhydride or fumaiic acid to produce the fatty acid Diels-Alder adduct or the fatty acid-ene reaction product [31]. This reaction product is further reacted in a condensation or hydrolyzation reaction with a polyalcohol to form an acid-anhydride ester corrosion inhibitor. The ester may be reacted with amines, metal hydroxides, metal oxides, ammonia, and combinations thereof to neutralize the ester. Surfactants may be added to tailor the inhibitor formulation to meet the specific needs of the user, that is, the corrosion inhibitor may be formulated to produce an oil-soluble, highly water-dispersible corrosion inhibitor or an oil-dispersible, water-soluble corrosion inhibitor. Suitable carrier solvents may be used as needed to disperse the corrosion inhibitor formulation. 

Polyesters may be used [27-30,223] instead of a fatty acid modifier for imidazoline. Thus a corrosion inhibitor with film-forming and film-persistency characteristics can be produced by first reacting, in a condensation reaction, a polybasic acid with a polyalcohol to form a partial ester. The partial ester is reacted with imidazoline or fatty diamines to result in a salt of the ester. Oil-soluble, highly water-dispersible corrosion inhibitor or oil-dispersible. 

In the same way, a crosslinked oxalkylated polyalkylene polyamine can be obtained by preparing a completely oxalkylated polyalkylene polyamine with a degree of polymerization of 10 to 300, crosslinked with a polyalcohol. The demulsifying agent is made from a mixture of the crosslinked oxalkylated polyalkylene polyamine with 25% to 75% by weight of an oxethylated or oxypropylated isoalkylphenol-formaldehyde resin [154]. 

Hidaka H., and Yamazaki M., 2004, New PCMs prepared from erythrito 1-polyalcohols mixtures for latent heat storage between 80 and 100 °C, J. Chem. Eng. Jap. 37 1155—1162. 

The polymers prepared from thexylborane and diene monomers were reacted with carbon monoxide at 120°C, followed by treatment with NaOH and H202 to produce a polyalcohol (scheme 5).13 This conversion includes migration of the polymer chain and thexyl group from the boron atom to carbon, as shown in scheme 5. When this reaction was carried out under milder condition, poly(ketone) segments were included in the polymer backbone due to an incomplete migration of the thexyl group. 

Moog RS, Ediger MD, Boxer SG, Fayer MD (1982) Viscosity dependence of the rotational reorientation of rhodamine B in mono- and polyalcohols. Picosecond transient grating experiments. J Phys Chem 86 4694-4700... 

Polymer linkages that do not release condensates on being formed include polyurethanes (diisocyanate/polyalcohol) and epoxy (ring opening of the epoxy... 

Lommerts BJ (1994) Structure development in polyketone and polyalcohol fibres. PhD thesis, University of Groningen... 

Asymmetric hydrogenations catalyzed by supported transition metal complexes have included use of both chiral support materials (poly-imines, polysaccharides, and polyalcohols), and bonded chiral phosphines, although there have been only a few reports in this area. 

Latterly, some oil-in-water adjuvants have been developed. Many are squalene-in-water emulsions. Emulsifiers most commonly used include polyalcohols, such as Tween and Span. In some cases, immunostimulatory molecules (including MDP and TDM see Section 13.5.4) have also been incorporated in order to enhance adjuvanticity. These continue to be carefully assessed and may well form a future family of useful adjuvant preparations. 

---