Sorbitol 2.4 molar

Conditions Sorbitol (3.64 g) and lauric acid (24.0 g) (molar ratio 1 6) were heated in the presence of the mesoporous sulfonic acid catalyst (0.36 g) for 24 h at 110 °C. Analysis by size-exclusion HPLC and NMR... 

Furthermore, the decrease in water content of aqueous soltitions of the dimer by added saccharides reduced the reaction rate of the dimer with Y, as should be expected for the reaction (9), in case of an 1 mechanism. For example, when the molarity of water was brought from 55.5 to 27.7 by adding sorbitol or glucose, the rate constant of the reaction of the dimer with pyridine decreased from... 

To obtain water-insoluble sorbitol copolyesters, 1,8-octanediol was used in place of a fraction of sorbitol in the monomer feed. Adipic acid, 1,8-octanediol, and sorbitol were copolymerized in the molar ratio 50 35 15 (Table 1, entry 2). The methanol-insoluble product had an Mw of 1.17x10. The solubility in water and THF of entry 1 and 2 products, respectively, is direct proof that they have few interchain crosslinks. Furthermore, 0.6- 1.0% w/v solutions of the products passed through 0.45 Um filters with complete recovery of the products which demonstrates the absence of microgels. This was shown by the fact that 99.9%wt of polymer was recovered when a known concentration of polymer solution was passed through the filter and the solvent was evirated. 

The compositions and absolute molecular weights reported in Table 1 were determined by NMR and GPC-MALS, respectively. Poly(apidic acid-co-octanediol-co-sorbitol) (PAOS) containing (1, 5, 12 and 18) % (mol fraction) sorbitol units have relative molar mass values that are similar (43,000 to 60,000). However, the 27 % (mol fraction) copolymer has a relative molar mass value of 117,000. We believe that the high molecular weight reported for 27 % PAOS is due to branching and an increased propensity for interchain coupling reactions that occur between non-chain end repeat units. 

The oxidation in such a batch process would be complete in 24 h, but it can be extended by adding additional sorbitol (up to a final concentration of 28%) during the fermentation. However some modern processes use continuous fermentation (see section 6.4.2) so that a continuous input of D-sorbitol is matched by the output of L-sorbose, and the fermenter itself becomes a large catalytic converter. The molar yield of L-sorbose in these processes is usually greater than 85%. 

A regioselective direct dehydration polycondensation between a polyol sugar component, sorbitol, and an adipic acid was carried out with a CALB catalyst at 90 °C for 48 h. The product, polysorbityl adipate, was water-soluble the Mn and MW values were 10,880 and 17,030 Da, respectively. Sorbitol was esterified at the primary alcohol group of 1-and 6-positions with high regioselectivity (85 5%). To obtain a water-insoluble sorbitol polyester, sorbitol, adipic acid and 1,8-octanediol (molar ratio 15 50 35) were terpolymerised at 90 °C for 42 h. The methanol-insoluble portion (80%) had an MW of 1.17 x 10 [30]. 

Molarity with respect to sorbitol. Only during PIA2 treatment. 

Rana et al prepared P(2-EHA)-silicate nanocomposites by batch emulsion polymerization of 2-EHA in the presence of sorbitol, using potassium persulfate as initiator. The nanocomposites so prepared were shown to be intercalated by XRD, TEM and IR spectroscopy. However, according to the authors," the nanocomposite failed to satisfy the desired application in transdermal drug delivery. Consequently, they improved their product by preparing a P(2-EHA-cu-AA)-silieate nanocomposite. AA was chosen for its polarity and known bioadhesive properties and 2-EHA for its hydrophobicity and softness. Copolymers with different molar ratios of the monomers were prepared. Sorbitol was used as emulsifier and benzoyl peroxide as initiator therefore, the synthesis process" may be classified as suspension copolymerization. The drug cloxacillin sodium was added to the reaction mixture after 2 h of polymerization and 1 h before the reaction was terminated. The nanocomposites so prepared were shown to be intercalated by XRD and TEM. NMR and IR spectroscopy confirmed the copolymer formation and the absence of monomer impurities in the product. 

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