Alkanes diols

Rafler el al. [105] applied the two-film model to the mass transfer of different alkane diols in poly(alkylene terephthalate) melts and demonstrated a pressure dependency of the mass-transfer coefficient in experiments at 280 °C in a small 3.6L stirred reactor. They concluded that the mass-transfer coefficient kij is proportional to the reciprocal of the molecular weight of the evaporating molecule. 

TABLE 2-2 Rate Constants for Polyesterification (26.9° C) of Sebacoyl Chloride with a,co-Alkane Diols in Dioxane" b... 

Very often, the transesterification reaction implies the need for an alkylene or CC (e.g., EC or PC) and an alcohol in the presence of either a homogeneous or heterogeneous acidic or basic catalyst [268], to co-produce dialkyl carbonate and the alkane diol or glycol (Equation 7.30). 

Dinitrophenol was used with benzyloxy-bis(diisopropylamino)phosphine 243 to synthesize the cyclic phosphate derivatives 244 of a series of alkane diols (HO-(CH2) -OH n = 4-6) in good isolated yields <2004TL1001>. 

The first example of the asymmetric synthesis of P-chiral trialkyl phosphates (12) via trialkyl phosphite, in which the keystone is dynamic kinetic resolution in the condensation of a dialkyl phosphorochloridite (13) and an alcohol by the catalytic assistance of a chiral amine has been reported (Figure 2)." 2,4-Dinitrophenol (DNP) was employed as an activating reagent with ben-zyloxy-bis-(diisopropylamino) phosphite to synthesize the cyclic phosphate derivatives (14) from a series of alkane diols HO-(CH2)n-OH (n=2-6). Included was a cyclic phosphate derivative of carbohydrate (15). The mechanism of activation by 2,4-DNP and cyclization was also described (Figure 3). ... 

The elution strength of hybrid micellar mobile phases was measured for a number of organic additives (alcohols, alkane diols, alkanes, alkylnitriles, and dipolar aprotic solvents, such as dimethyl sulfoxide and dioxane) added to micellar SDS, CTAC, and Brij-SS. Benzene and 2-ethylanthraquinone were used as probe compounds. The presence of alcohols, alkane diols, alkylnitriles, and dipolar aprotic solvents produced a diminution of the retention times, reaching remarkable levels for the most hydro-phobic compound (2-ethylanthraquinone). The observed elution strength order roughly paralleled the octanol-water partition coefficients of the additives, Rq/w (Fig- 2), or their ability to bind to micelles, am- In contrast, alkanes (pentane, hexane, and cyclohexane) had relatively little effect on the retention. 

Plots of Po/w or vs. plate counts for benzene and 2-ethylanthraquinone eluted with micellar SDS, in the presence of several alkanols and alkane diols, show an initial steep increase in efficiency, after which an approximately constant value is reached (Fig. 3). Among the alcohols, maximal efficiency for benzene and 2-ethylanthraquinone is obtained with the butanols and the pen-tanols, with enhancement factors of 2.5 and 25 (compared to pure SDS), respectively. However, final efficiencies for the latter compound are much lower compared to that for benzene. Dipolar aprotic modifiers (acetonitrile or dimethylsulfoxide) appear to be somewhat more effective in enhancing efficiencies than alcohols with comparable Pq/w- Some recent work has shown the advantage of using acetonitrile as additive in MLC for the analysis of sulfonamides, tetracyclines, and the most polar steroids. 

Bridged or reinforced azamacrocycles, which have pairs of nitrogen atoms of an aza-macrocycle linked, usually by an a,cu-alkandiyl bridge, 154 are prepared by reaction of a cyclic amine with a bifunctional nucleophile, such as an a,cu-dibromoalkane or an a,cu-ditosyl-alkane-diol. Bis(acyl esters), amides, and halides react with amines to form bicyclic amides which can be reduced to the bicyclic amines.155 The bridge can have internal functions, such as C=C or o-C6H4 (or include hetero atoms, thus forming clathrochelates).156... 

A very recent synthesis of a thermotropic copolyimide contains an AT-(car-boxyphenyl) trimellitimide ester unit linked to a p-aminobenzoic acid via an amide linkage, which in turn is linked by an alkane diol unit back to the trimellitimide unit [86]. This is probably the first example of a copoly(ester-amide-im-ide) with mesogenic properties identified. Its MI score is 9.6. 

Chang and Hung [83] have synthesised 22 below, in which an extra double bond is inserted into the N-(4-carboxyphenyl trimellitimide) unit. When copolymerised with an even chain alkane diol, an enantiotropic PEI is formed (MI=10) when the spacer is odd, only a transient monotropic phase is observed (MI=9.4). This is further evidence that the critical value for mesogenicity in PEIs is close to 9.5. It is of interest to note that the diacid employed in the copolymer, N-(car-boxyphenylacrylic) trimellitic anhydride acts as the complete mesogenic unit for the copolymer. 

The polymerization of substrates varying in a,(o-n-alkane diol and a,co- -alkane diacid chain length by Humicola insolens cutinase immobilized on Amberzyme oxiranes (HiC-AO) and Novozym 435 was studied [39], HIC-AO... 

Raney catalysts are used in a broad range of industrial hydrogenations. These include reductions of nitriles and dinitriles (e.g. for nylon intermediates), aldehydes (e.g. for sorbitol or alkane diols), olefins and alkynes (e.g. for monomer purification) and aromatic nitro compounds (e.g. for urethane intermediates). 

It is evident that, although there is a decrease in reactivity with increased molecular size, the effect is significant only at a very small size. The reaction rate constant very quickly reaches a limiting value at x = 3, which remains constant and independent of molecular size. Analogous results are found for the polyesterification of sebacoyl chloride with a,or-alkane diols [Ueberreiter and Engel, 1977] ... 

Zia, K.M., Barikani, M., Zuber, M., Bhatti, I.A. Surface Characteristics of UV-irradiated Polyurethane Elastomers extended with alkane Diols Islam-ud-Din. App. Surf. Sci. 254, 6754-6761 (2008c)... 

Nagata and Hizakae [153] reported preparation of a series of photocross-linkable biodegradable polymers by condensation of dichlorides of 4,4 -(adipoyldioxy)dicinnamic acid and alkane diols of various methylene lengths. They also used various poly(ethylene glycols) with molecular weights ranging from 200 to 8,300. 

A study was made on the effect of different organic ditives i.e., alcohols, alkane diols, alkanes, alkylnitriles, and dipolar aprotic solvents such as dimethyl sulfoxide and dioxane) upon the elution strength of micellar... 

The polycondensation reactions of sebacoyl chloride with [Pg.83]

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