The effects of solvent on the transition kinetics of polymorphic modifications of stearic acid were examd. in polar and nonpolar solns. Two typical polymorphs, B (low-temp. stable) and C (high-temp. stable), and the solvents (butanone, methanol, n-hexane, and decane) were studied. In all solns. the transitions from B to C and from C to B took place at temps. above and below 32°, at which the free energies of B and C have the same value, resp. The rates of the C → B transition were significantly dependent both on temp. and solvent. First, the transition rate was fastest between 22 and 26°. This was due to 2 conflicting factors; the free energy difference between B and C which decreases as the temp. approaches 32°, and the rates of dissoln. of C and growth of B which increase with temp.. Secondly, the solvent exclusively influenced the C → B transition; polar solvents, esp. methanol, caused a significantly more rapid transition than nonpolar solvents, the rates being relatively higher than those prediced by the soly. values. It was inferred that the different growth units (monomers in the polar solvents and dimers in the nonpolar ones) and the twisted lateral interface structures of the B polymorph would be responsible for the present solvent effect. [on SciFinder(R)]

The reaction of Na stearate [822-16-2] with epichlorohydrin [106-89-8] in the presence of phase-transfer catalysts (tetraalkylammonium halides) gave 90% glycerol monostearate [31566-31-1] with purity 97%. The effect of reactant ratio, catalyst type and concn., and temp. were studied. An efficient, economical process was developed, including recycle of solvent and excess epichlorohydrin and recovery of 80% catalyst. The monoglycerides so prepd. are not food grade, but com. monoglycerides can be prepd. [on SciFinder(R)]

A high-performance liq. chromatog. method was used for the anal. of nonionic surfactants (oleyl and dibromostearyl alcs. ethoxylated with 1-20 oxyethylene units). The method involved the use of a Lichrosorb SI-60 (10 $μ$) column (4.6 mm internal diam., 25 cm long) with a hexane-MeOH-Me2CHOH mixt. as the mobile phase at 50° with UV detection at 220 nm. No derivatization of the ethoxylates was required. An improved baseline was achieved by adding anthracene to the eluents. [on SciFinder(R)]

High-performance liq. chromatog. was used to sep. and identify oleate and 9,10-dibromostearate esters of polyethylene glycols having various d.p. A Lichrosorb SI-60 (10 $μ$m) column was used with gradient elution (using a mixt. of iso-PrOH, MeOH, and hexane at 50°) and UV detection at 220 nm for the best sepn. of ethoxylates having d.p. ≤20. No derivatization of the ethoxylates was required. An improved baseline was obtained by adding negligible amts. of anthracene to the eluent. [on SciFinder(R)]

Crystal size distribution and the yield of Ca oxalate crystals were detd. in solns. with an admixt. of 5 normal and 3 stone forming urines. A pos. correlation was found between the median size and no. of particles and the overall inhibitory potentials of the urines toward Ca oxalate pptn. in vitro as reflected by discriminating index (DI) [sic] measurements. Incubation of 2 samples of stone formers' (SF) urines with glutamic-oxalacetic-transaminase (GOT) caused a redn. of aspartic acid concn., an increase in glutamic acid concn. and a parallel decrease in the DI values. After 90 min of SF urine incubation with GOT the DI in three samples was improved and both the median size and no. of particles were reduced, by 28% and 45% resp. These results could indicate that GOT activity changes the inhibitory power of the SF urine by transforming aspartic acid into glutamic acid, having thus most probably a part in the inhibition of Ca oxalate stone formation. [on SciFinder(R)]

Solubilities were detd. at 11-50° in MeOH, EtOH, Me2CO, MeCN, and iso-PrOH and in some aq. mixts. of these solvents. The soly. data are represented by best-fit equations for each solvent. [on SciFinder(R)]

Surfactants prepd. by bromination of the double bonds of oleate groups of sorbitan monooleate (I), sorbitan trioleate (II), and polyoxyethylene derivs. of I and II were effective emulsifiers in the prepn. of oil-in-water emulsions. The HLB values of the brominated compds. were similar to those of starting compds. The use, formation, and the stability of emulsions were detd. [on SciFinder(R)]

Correlation between the degree of satn. of both emulsifiers and vegetable oils has been examd. for a variety of water-in-oil (w/O) emulsions. Emulsions prepd. with unsatd. emulsifiers and highly unsatd. vegetable oils (contg. mainly oleic and linoleic acids) were more stable than those prepd. with some unsatd. emulsifiers and vegetable oils consisting of less unsatd. fatty acids. Moreover, emulsions prepd. with satd. emulsifiers and fully satd. oils have shown better stability than similar emulsions prepd. with less satd. oils. Since rigidity of the emulsifier and emulsifier-oil interactions on the film are dominant factors in stabilization of w/o emulsions, it is suggested to stabilize water in unsatd. vegetable oil emulsions using specially designed polyglycerol esters of dimerized soybean oil to achieve both requirements. [on SciFinder(R)]

Orange essential oil was emulsified with water in the presence of various food additives (xanthan gum [11138-66-2], sorbitan monolaurate [1338-39-2], sorbitan monooleate [1338-43-8], ethoxylated sorbitan monooleate [9005-65-6], sucrose diacetate hexaisobutyrate [126-13-6], tragacanth gum [9000-65-1], and ester gum 8BG) and tested for light scattering quality, opacity, and stability, to det. the proper emulsifying agents for use in creating cloudy emulsions in soft drink manuf. Best results were obtained by using combinations of ester gums and the emulsifying agents. [on SciFinder(R)]