Trimethylene Glycol Research Articles

Synthesis of imines, diimines and macrocyclic diimines as possible ligands, in aqueous solution

Although it is recognized that the presence of water is disadvantageous for imine synthesis, we demonstrate that such synthesis can be effective in completely aqueous media, without any catalyst and under mild conditions. Thus, aryl-aryl, aryl-alkyl, alkyl-aryl and alkyl-alkyl monoimines as well as a large variety of diimines are obtained by direct condensation of the corresponding carbonyl compounds and amines, in water. The same process is used to synthesize macrocyclic diimines starting from methylene, ethylene, trimethylene and tetramethylene glycol bis(2-formylphenyl ether) and ethylene-, trimethylene- and tetramethylene-diamine, some of these macrocycles being known for their chelating properties.

Preparation and Characterization of Inclusion Complexes of Poly(alkyl vinyl ether) with Cyclodextrins

Abstract γ-Cyclodextrin (γ-CD) has been found to form inclusion complexes with poly(methyl vinyl ether) (PMVE), poly(ethyl vinyl ether) (PEVE), and poly(n-propyl vinyl ether) (PnPVE) of various molecular weights to give stoichiometric compounds in crystalline states. α-Cyclodextrin (α-CD) and β-cyclodextrin (β-CD) did not form complexes with poly(alkyl vinyl ether)s of any molecular weight. γ-CD did not form complexes with the low molecular weight analogs, such as diethyl ether and trimethylene glycol dimethyl ether. The yields of the complexes of γ-CD with PMVE increased with increasing molecular weight (MW) of PMVE and reached saturation at about MW 2000. The yields of the complexes of γ-CD with PEVE and PnPVE increased with increase in MW, reached a maximum at a MW of about 1000 for PEVE and about 250 for PnPVE, and decreased with a further increase in the MW. Complexes were isolated and found to have a 3 : 1 (monomer unit : CD) ratio. The complexes were characterized by IR, 1H NMR, 13C NMR, and X-ray (powder), thermal and elemental analyses. The structures of the complexes are discussed.

MOCA and some proposed substitutes (Cyanacure, Conacure, Polacure 740M and Ethacure 300) as two-stage skin carcinogens in HRA/Skh hairless mice

4,4′-Methylenebis(2-chlororaniline) (MOCA) is a suspect human carcinogen that has wide use as an industrial compound. Occupationally, exposure may occur through inhalation and ingestion, but skin absorption is the main route by which this compound gains entry into the body. Because of the justified concern about the continued use of MOCA, a number of substitutes have been proposed, including 1,2-bis(2-aminophenylthio)ethane (Cyanacure), Conacure, trimethylene glycol di- p-aminobenzoate (Polacure 740M) and 3,5-dimethylthio-2,4-toluenediamine/3,5-dimethylthio-2,6-toluenediamine (Ethacure 300). There is very little information available about these substances, but they share the property of belonging to the same class (aromatic amines) as MOCA. Furthermore, at least two (Ethacure 300 and Cyanacure) are mutagenic in Salmonella. This study was undertaken to investigate if MOCA and substitutes, Polacure 740M, Ethacure 300, Cyanacure and Conacure have the potential to cause papillomas in a two stage initiation/promotion protocol in HRA/Skh hairless mice. When a maximum dose of 100 mg of substance was applied to the dorsal skin of these mice, Ethacure 300 and Cyanacure were markedly toxic. All of the compounds had little or no effect on skin tumor initiating activity following 12- O-tetradecanoylphorbol-13-acetate (TPA) promotion. One experiment with MOCA suggested that, at lower and less toxic dose, this substance may have promotional activity. Therefore, caution should still be exercised when using these compounds and it cannot be excluded that they may be active in other strains of mice or other laboratory animal species.

Syntheses, structure analyses, and reactions of 1,3,5-trioxepanes and related compounds

Acid-catalysed condensations of 1,5- or 1,6-dicarbonyl compounds with ethylene glycol give 1,3,5-trioxepane derivatives as a result of neighbouring participation by the adjacent carbonyl group during the acetalization process. With trimethylene glycol, the related 1,3,5-trioxocanes have also been obtained. Reaction of the 1,3,5-trioxepanes with (a) Grignard reagents gives dialkyl-substituted cyclic ethers, (b) titanium tetrachloride–allyltributyltin gives diallyl-substituted cyclic ethers and (c) triethylsilane in the presence of trimethylsilyl triflate provides the corresponding cyclic ethers.

Free radical-scavenging dyes as indicators of frontal polymerization dynamics

A novel method of monitoring frontal polymerization propagation has been presented. Using commercially available dyes that change color upon coupling with free radicals, the propagating fronts of free radical polymerization reactions can be visualized and recorded using conventional digital imaging techniques. To demonstrate the utility of this method, we have applied it in the frontal polymerization reactions of trimethylene glycol dimethacrylate (TGDMA) and 1,6-hexanediol diacrylate (HDDA), with Lupersol 231 [1,1-di(tert-butylperoxy)-3,3,5-trimethylcylohexane] as the initiator.

Condensation of supersaturated vapors of hydrogen bonding molecules: Ethylene glycol, propylene glycol, trimethylene glycol, and glycerol

The critical supersaturations required for the homogeneous nucleation (rate of 1 drop cm−3 s−1) of ethylene glycol, propylene glycol, trimethylene glycol and glycerol vapors have been measured over wide temperature ranges (e.g., 280–400 K) using an upward thermal diffusion cloud chamber. At lower temperatures the experimental nucleation rates are much higher than the predictions of the classical nucleation theory. Glycerol shows the best agreement between experiment and theory in the temperature range of 340–370 K. An apparent increase in the critical supersaturation of glycerol is observed with increasing carrier gas (helium) pressure and this effect is more pronounced at lower temperatures. The results from corresponding states and scaled nucleation models indicate that the nucleation behavior of glycerol is quite different from other glycols. Glycerol requires higher critical supersaturations compared to the other glycols at the same reduced temperatures. This implies quite small critical clusters for glycerol (20–50 molecules) in the temperature range 300–380 K. The discrepancy between experiment and theory at lower temperatures may be explained by considering that the surface tension of the critical clusters is lower than the bulk surface tension. It is, however, surprising that a Tolman type correction for the curvature dependent surface tension could be applicable for such small critical clusters. Further theoretical work is required in order to fully understand the observed higher nucleation rates at lower temperatures of glycols and glycerol.

Effects of Polyhydric Alcohols on the Mechanical Properties of Soy Protein Plastics

Abstract Polyhydric alcohols, i.e., ethylene glycol, glycerol, propylene glycol, 1,3-propanediol (trimethylene glycol), and polyethylene glycol (200 and 400), were investigated for their plasticizing effects on soy protein plastics. Tensile strength and percentage elongation at break of compression-molded soy protein specimens containing each of the polyhydric alcohols were measured, and Young's modulus was calculated. Ethylene glycol and glycerol demonstrated the greatest effects on the tensile properties. Differential scanning calorimetric (DSC) thermograms of soy protein with glycerol showed a major exothermic transition. Dynamic mechanical spectra showed that dry plastic specimens had a shear-storage modulus (G' = 1.76 GPa) about 50% larger than those of the high performance synthetic polymers tested. The shear-storage modulus was little dependent on temperature change up to ca. 130°C. After the specimens were moisturized at 50% relative humidity, the G' was reduced to 0.22 GPa. The shear-storage modulus of specimens containing 30% glycerol decreased when the temperature increased above −60°C. Rheological properties of soy protein with and without glycerol were evaluated by using a torque rheometer.

Quick Measurement of Brillouin Spectra of Glass-Forming Material Trimethylene Glycol by Angular Dispersion-Type Fabry-Perot Interferometer System

Brillouin scattering of Trimethylene Glycol which often crystallizes on slow cooling was measured from 197 K to 426 K using the angular dispersion-type Fabry-Perot interferometer with a CCD detector. Especially the Brillouin spectra on the cooling from 300 K to 197 K could be observed only in 1.5 h without crystallization. The observed sound velocity and anomalous attenuation are analyzed by a single relaxation model. The relaxation frequency obeys the Arrhenius law with an activation energy of 3.71 kcal/mol. This suggests that the observed sound anomaly is due to the fast β-relaxation process.

Anomalous behavior of thermosetting systems after cure vs. chemical conversion: A normalized conversion–temperature–property diagram

AbstractIsothermal properties of thermosetting materials after cure, such as density and modulus, pass through maximum and minimum values with increasing chemical conversion. In this report observed decreases in modulus and density at isothermal temperatures below the glass‐transition temperature, Tg, are termed “anomalous.” Four diepoxide (diglycidyl ether of bisphenol A) and tetrafunctional diamine (trimethylene glycol di‐p‐aminobenzoate) high Tg thermosetting systems with different ratios of amine to epoxy were investigated for the purpose of analyzing the evolution of the isothermal properties with increasing conversion. The density, Tg, and modulus of the materials with increasing conversion were measured by a combination of dilatometric, differential scanning calorimetry, and torsional braid analysis techniques. The results are presented in the form of conversion–temperature–property (TgTP) diagrams with modulus and density as the properties. Tg is used as a direct measure of conversion based on the one‐to‐one relationship between Tg and conversion. The property‐conversion behavior of the systems with different ratios of amine to epoxy show similar behavior if Tg is used as the measure of conversion and the data are normalized with respect to Tg at a conversion corresponding to the lower limit of the conversion range at which a maximum in the isothermal modulus occurs. The conversion corresponding to molecular gelation, gelTg, correlates with the lower limit of the conversion range at which the maximum in isothermal modulus occurs; gelTg also marks a change in the behavior of the sub‐Tg mechanical relaxations vs. conversion. The conversion corresponding to the maximum in isothermal modulus vs. conversion correlates with the conversion corresponding to the maximum in isothermal density vs. conversion. © 1995 John Wiley & Sons, Inc.

Free volume after cure vs. fractional conversion for a high‐Tg epoxy/amine thermosetting system

AbstractIsothermal glassy‐state properties of cured thermosetting materials pass through maximum and minimum values with increasing fractional chemical conversion. In this work, a diglycidyl ether of bisphenol A (a diepoxide) and trimethylene glycol di‐p‐aminobenzoate (a tetrafunctional aromatic diamine) system was investigated for the purpose of analyzing the complex behavior after cure of the isothermal properties of the glassy state with increasing conversion. The glass transition temperature (Tg) is used as a direct measure of conversion. Dilatometric, differential scanning calorimetry, torsional braid analysis, and positron annihilation spectroscopy techniques were used to monitor the density, Tg, modulus, and free volume of the material after cure with increasing conversion. The specific volume at 25°C after cure passes through a minimum and the modulus passes through a maximum with increasing conversion. The fractional free volume and the average radius of free volume at 25°C after cure pass through minimum values with respect to conversion. The specific volume, modulus, and fractional free volume at 25°C vs. conversion data qualitatively correlate. The anomaly of the increasing specific volume in the glassy state with increasing conversion is thus considered to arise from changes in free volume on a length scale corresponding to angstroms. The increasing free volume with increasing conversion is related to the phenomenon of antiplasticization. © 1995 John Wiley & Sons, Inc.

Assessment of macroporous polystyrene-based polymers for the immobilization of Citrobacter freundii

POLYHIPE™ polymers represent a novel immobilization support possessing many desirable characteristics. These materials have been used to immobilize Citrobacter freundii in order to develop a continuous bioconversion system for the anaerobic production of trimethylene glycol from glycerol. Several immobilization methods were employed, of which the most successful involved culturing the organism with POLYHIPE in shake-flasks, transferring the contents into a column, and growing the cells in situ within the column. Cell activity was determined by the amount of TMG produced from a buffered glycerol solution. The latter was passed through the columns by either a recirculation system or the superior single-pass method. The optimal system was scaled up and showed potential for further large-scale investigations. Cell lifetime in the column could be improved by supplying the cells with diluted growth medium in place of the buffer.

Competitive primary amine/epoxy and secondary amine/epoxy reactions: Effect on the isothermal time‐to‐vitrify

AbstractThe effect of temperature on the ratio of the kinetic rate constants, k2/k1, has been investigated using FTIR spectroscopy for the competing reactions of epoxy with secondary amine (k2) and primary amine groups (k1) in a trimethylene glycol di‐p‐aminobenzoate/diglycidyl ether of the bisphenol A system. The ratio of the rate constants increases from 0.16 to 0.33 in the temperature range 100−160°C. The corresponding difference in the activation energies for the competing reactions is about 3.7 kcal/mol. The effect of the ratio on the time‐to‐vitrify contour of the isothermal time–temperature–transformation (TTT) cure diagram is discussed: The effect is more significant at higher curing temperatures.

Synthesis and Properties of Polyamides, Polyimides, and a Polyamide-Imide Based on Trimethylene Glycol-Di-p-Aminobenzoate

Abstract New polyamides, polyimides, and a polyamide-imide containing ester linkages were prepared by the reaction of trimethylene glycol di-p-aminobenzoate with terephthaloyl chloride, isophthaloyl chloride, adipoyl chloride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, and trimellitoyl chloride. the low temperature solution and interfacial polymerization techniques were utilized to prepare the above-mentioned polymers. the polymers thus prepared were found to be soluble in solvents like DMAC and DMSO and had inherent viscosities in the 0.15-0.60 range. the polyimides prepared formed transparent and flexible films.

Thermal behaviour and morphology of copolyterephthalates derived from trimethylene glycols

AbstractThe thermal behaviour and the morphology of four polyterephthalate samples have been studied. Two of these samples are the pure homopolymers poly(trimethylene terephthalate) (PTMT) and poly(oxyditrimethylene terephthalate) (PTMTMT), while the other two are copolymers of both polyesters with 13 and 33% by weight of PTMTMT. It was found that the insertion of units of PTMTMT in the copolymers derived from PTMT produces a depression of the glass transition and melting temperatures as a consequence of the higher flexibility of the former units, and several equations have been tested to fit that depression. Moreover, the crystallization rate of PTMTMT was found to be very slow, and the need for higher supercoolings to crystallize the samples in a reasonable time, as the PTMTMT content increases, implies the formation of a greater number of nuclei, with subsequent inconvenience when trying to follow the evolution of the radii of the observed spherulites. On the other hand, well developed spherulites were obtained for the samples rich in PTMT, and two different kinds of this superstructure were observed, depending on the crystallization temperature.

Oligomerization of oxetane and synthesis of polyterephthalates derived from 1,3‐propanediol and 3,3′‐oxydipropanol

AbstractThe oligomerization of oxetane (trimethylene oxide) initiated by sulfuric acid in methylene chloride in the presence of 1,3‐propanediol (trimethylene glycol) leads to the formation of α‐hydro‐ω‐hydroxyoligo(oxytrimethylene)s. The effect of adding different amounts of trimethylene glycol was studied, and the dimer, 3,3′‐oxydipropanol, could be isolated. Polymers from dimethyl terephthalate and 3,3′‐oxydipropanol and copolymers from 1,3‐propanediol, 3,3′‐oxydipropanol and dimethyl terephthalate were synthesized. The influence of the chemical structure on their thermal transitions was analyzed.

Production and isolation of reuterin, a growth inhibitor produced by Lactobacillus reuteri.

Lactobacillus reuteri is a prominent member of the Lactobacillus population in the gastrointestinal ecosystem of humans, poultry, swine, and other animals. Reuterin is a newly discovered, broad-spectrum antimicrobial substance produced by this species during fermentation of glycerol. In this report, we describe procedures for (i) producing reuterin in sufficient amounts to isolate from a fermentation mixture and (ii) isolating this substance by high-performance liquid chromatography. By using uniformly labeled [14C]glycerol, reuterin was identified as a product of glycerol fermentation associated with the production of beta-hydroxypropionic acid and trimethylene glycol.

Dynamic mechanical relaxations of polyterephthalates based on trimethylene glycols

AbstractThe dynamic mechanical relaxations of poly(trimethylene glycol terephthalate) (PTMT), poly(ditrimethylene glycol terephthalate) (PDTMT) and two copolymers obtained from them have been studied between − 150 and 200°C with a dynamic viscoelastometer. The four polymers show three relaxations that are designated α, β, and γ in order of decreasing temperature. The α relaxation is considered to be the glass transition of the polymers. The β relaxation is wider and weaker than the α, as normally occurs in the polyester series. The γ relaxation takes place at temperatures below − 100°C and is usually overlapped by the β relaxation. The influence of thermal and mechanical histories on the nature, location, and intensity of the three relaxations is studied and discussed.

Percutaneous absorption of nicardipine and ketorolac in rhesus monkeys.

Vehicle effects on the percutaneous absorption of nicardipine base, nicardipine hydrochloride, ketorolac acid, and ketorolac tromethamine were determined using the rhesus monkey as an in vivo model for human skin penetration. Vehicles investigated included blends of propylene glycol, trimethylene glycol, ethanol, Azone, Tween 20, water, and long-chain fatty acids. Formulations were prepared such that the compound dose, application area, and percentage saturation of the compound in the vehicle were held constant. Variations in absorption of the compounds were therefore attributable to vehicle effects. Each formulation was applied to three monkeys for a period of 24 hr using 10 Hill Top Chambers. Plasma samples were taken at appropriate intervals for 36 to 48 hr. The results indicated that trimethylene glycol and Tween 20 did not enhance absorption of the test compounds despite claims by other investigators. Azone and ethanol provided moderate enhancement of both the rate and the extent of absorption, while long-chain fatty acids in combination with propylene glycol significantly enhanced penetration. In general, higher fluxes were observed with the more lipophilic compounds nicardipine base and ketorolac acid as compared to the hydrochloride and tromethamine salts.

ChemInform Abstract: Fragmentation and Isomerization Reactions of Phenyl Substituted 2‐Oxo‐ 1,3,2‐dioxathianes (Trimethylene Sulfites).

AbstractThe cyclic sulfites (I) ‐ (III) and (XI) are synthesized from the corresponding trimethylene glycols such as (X) with thionyl chloride.

The Relative Thermal Stability of Polyurethane Elastomers: 3. Influence of Chain Extender Structure

A method of using high melting point chain extenders in the synthesis of castable polyurethane elastomers (PU) based on the system polycaprolactone diol (Capa 225) and trans 1,4–cyclohexane diisocyanate (CHDI) was developed based on a semi-prepolymer (quasi) technique in which the high melting point chain extender was first dissolved in polyol before mixing with the diisocyanate. Using this technique it was found possible to carry out a bulk polymerisation in the normal PU reaction temperature range of 100–130°C.Thermal stability properties were measured by means of DMTA and DSC and the temperature at which the value of dynamic storage modulus (log E') changed significantly in the rubber region used to indicate the limit of thermal stability of the polyurethanes. As the molecular symmetry of the chain extender increases so does the thermal stability of the resulting PU.The best thermal stability was obtained by the use of diamine chain extender, trimethylene glycol di-p-aminobenzoate which results in a polymer thermally stable to 230°C.Using an odd molar ratio of polyol/diisocyanate, with diisocyanate being present in excess, also enhances thermal stability by the formation of isocyanurate crosslinks: such PU elastomers retain their characteristically high elongation at break.