Polymer hydroxylated

Used industrially to cross-link hydroxylic polymers, polyethyleneimine. Possesses some carcinogenic properties. Polyethyleneimine is a hygroscopic liquid used in paper manufacture to confer wet strength and in textiles, alkylated derivatives also form useful polymers. 

A number of synthetic polymers having the abHity to control filtration rates at high temperature and in the presence of calcium and magnesium have also been developed (88). Such materials include vinyl sulfonate—vinyl amide copolymers (89,90), a copolymer of AMPS and A/,A/-dialkyl (meth) acrylamide (91) and a sulfonated hydroxylated polymer (92). AppHcation levels for these materials range from 5 to 18 kg/m (2—6 lb /bbl). Sulfonated asphalt is also used for high temperature filtration control. 

The addition of an a-hydroxycarboxyhc acid to a tetraethylene, propylene, diethjiene, or hexylene glycol titanate gives water-soluble complexes suitable for gelling aqueous solutions of hydroxyl polymers, such as poly(vinyl alcohol) (PVA), or cellulose (qv) derivatives. These are useful as binding agents for glass fibers, clays (qv), and paper coatings (85). 

Gelled Explosives. Aqueous solutions of water-dispersible, nonionic, natural hydroxylated polymers, such as galactomannans and their derivatives, can be cross-linked with organic titanates, such as TYZOR TE, TYZOR AA, and TYZOR LA to give water-bearing gels, which can be used to formgeUed explosives (532—534). 

Layer silicate minerals have a high selectivity of trace transition and heavy metals and greater irreversibility of their adsorption. Some chemisorbing sites such as -SiOH or AlOH groups may be at clay edges and form hydroxyl polymers at the mineral surface. Another possible reason for the high selectivity may be hydrolysis of the metal and strong adsorption of the hydrolysis ion species. 

Epoxy activation of hydroxylic polymers is commonly used as a means to immobilize molecules on solid phase chromatographic supports that contain hydroxyl groups (Sundberg and... 

The rhodium-catalyzed borylation of alkanes is applied to regiospecific functionalization of polyolefines.165,165a The reaction of polypropylenes (atactic, isotactic, and syndiotactic) with B2pin2 in the presence of Cp Rh( 74-C6Me6) catalyst at 200 °G affords the borylated polymers, which are treated with basic hydrogen peroxide in a mixture of THF and H20 to oxidize the boronate esters to the corresponding alcohols (Scheme 20). The hydroxylated polymers contain 0.2-1.5% hydroxymethyl side-chains. 

Since many proteases are specific in cleaving peptide linkages adjacent to substituent groups, we decided to prepare substituted polymers, anticipating that the introduction of the substituents would make the polymers more degradable. Methylated, benzylated, and hydroxylated polymers were prepared and their biodegradations have been studied. Compared to the unsubstituted polymers we found the substituted polymers more susceptible to attack by enzymes and microorganisms. (4, 6)... 

Our results suggest that in the cases of benzylated and hydroxylated polymers the biradical intermediates are stabilized by the phenyl and hydroxy group, resulting in a longer life for the intermediates. As a result, crosslinking becomes the favorable process. In the cases of the unsubstituted and the methylated polymers the short-lived biradicals lack such stabilization and the unimolcular fragmentation becomes the favorable process. 

It can be seen, therefore, that only three chemical materials form the basis of all the water-reducing admixtures, i. e. lignosulfonate, hydroxycarboxylic acid, and hydroxylated polymers. 

Hydroxycarboxylic acid at low dosage Hydroxylated polymer at low dosage Lignosulfonate + Ca formate Hydroxycarboxylic acid h-CaCl2 Lignosulfonate + Sod. thiocyanate Hydroxylated polymer Hydroxycarboxylic acid + surfactant... 

The efficiency of water-reducing admixtures, and their relative useMness are dependent on the aggregate-cement ratio. Hydroxylated polymer and... 

The data presented in this section illustrate that, with the exception of those accelerating water-reducing admixtures containing calcium chloride, there is an abundance of evidence to support the conclusion that water-reducing admixtures of lignosulfonate chemical form certainly will not accelerate any kind of corrosion with reinforcement and, when used to reduce the water-cement ratio, will form a more permeable and durable protective cover for the reinforcement. In view of the chemical nature of the other types of materials such as the hydroxycarboxylic acids and hydroxylated polymers, it seems most likely that these materials too would have no deleterious effect in this respect. 

Solid-phase synthesis of pyrido[2,3 pytirtiidines 514 was achieved by Hantzsch condensation of Wang resin-supported Knoevenagel derivative 513 with 6-aminouracil derivatives 512 as an a-oxo enamine component in the presence of ceric ammonium nitrate (CAN) in DMA followed by hydrolysis with TFA in CH2GI2. Compound 513 was prepared by treatment of a hydroxylated polymer, such as Wang or Sasrin resin, with diketene, followed by condensation with benzaldehyde (Equation 41) <1996TL4643>. 

In addition, hydroxyl polymers prepared by use of lithium alkyl acetal initiators have shown a high degree of functional purity (Table II). The functionality data for XI is a bit low, in part, because a linear GPC calibration was used to calculate nn (GPC). It should also be noted that Equations 1-9 proceed in the absence of anionic association or gel. 

To further test the functional purity of hydroxyl polymers prepared by the protected initiator and polymer route, two stage chain extensions of two polystyrene diols were carried out. The first stage involved conversion of the diols to acids with succinic anhydride the second stage involved chain extension with a diepoxide (Table III). If one assumes an overall conversion of 97-98%, a UP of 19 requires a functionality 1.93-1.95 based upon step-growth polymeri-... 

Scheme 7 a Reaction mechanism when sodium persulphate was used as hydroxylating agent for the polymer (P-H). b Decomposition of hydroxylated polymer P-OH at the surface, in the presence of ceric ammonium nitrate generated alkoxy radicals (P-0 ) which initiated the grafting... 

The efficiency of water-reducing admixtures, and their relative usefulness are dependent on the aggregate-cement ratio. Hydroxylated polymer and hydroxycarboxylic acid types are more effective than lignosulfonate-based materials at higher cement contents (lower aggregate-cement ratios), whilst the lignosulfonate... 

The first block (polybutadiene or polystyrene) is prepared by anionic polymerization, under high vacuum, in THF dilute solution (less than 5%), at low temperature (—70 °C) with cumylpotassium as initiator. Then, the living polymer is transformated into a hydroxylated polymer (PV—OH) by addition of ethylene oxide under vacuum, or into a carboxylated polymer (PV-COOH) by addition of carbon dioxide under vacuum. 

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