Trimethylene Glycol Research Articles

Alkenylcopper Reagents Prepared from Stereodefined Alkenylboronate Esters. Reaction with Allylic Halides as a Convenient Route to Stereodefined 1,4-Dienes

The stereo-defined synthesis of 1,4-dienes based on in situ generated stereo-defined alkenylcopper reagents is presented. The hydroboration of alkynes with dibromoborane-methyl sulfide complex followed by treatment with trimethylene glycol provides stable (E)-1-alkenylboronate esters. These boronate esters readily undergo “ate” complexes with a hindered base such as potassium-tert.-butoxide. The transmetalation of the alkenyl group from boron to copper via the “ate” complexes retains the original stereochemistry defined from the starting alkenylboronate esters. The effect of representative bases on stereodefined alkenylboronate esters and subsequent reaction of these boronate esters in the transmetalation reaction with copper(I) bromidemethyl sulfide is investigated. The resulting stereo-defined alkenyl copper species generated in situ readily couple with allylic bromide to give the corresponding 1,4-dienes with retention of stereochemistry. Since (Z)-1-alkenylboronate esters are easily accessible, both cisand trans-isomeric 1,4-dienes are synthesized.

The erosion/infiltration technique made by a polymer based on TEGDMA to mask the white lesions of the tooth

It is common to observe anterior teeth that present white opacities of enamel in relation to hypomineralization. These lesions alter social life of children and adults. There is a recent non-invasive treatment that can remove these stains without loss of substance, keeping tooth structure intact. This treatment modifies the optical properties of the white spot by infiltrating a polymer based on trimethylene glycol dimethacrylate (TEGDMA). This short article presents a method called erosion/ infiltration, which our team first described. Dentists must be aware of it, in order to treat patients with either fluorosis, MIH or trauma, so that much more invasive treatments such as veneers and crown can be avoided.

Green TPUs from Prepolymer Mixtures Designed by Controlling the Chemical Structure of Flexible Segments.

This study concerns green thermoplastic polyurethanes (TPU) obtained by controlling the chemical structure of flexible segments. Two types of bio-based polyether polyols—poly(trimethylene glycol)s—with average molecular weights ca. 1000 and 2700 Da were used (PO3G1000 and PO3G2700, respectively). TPUs were prepared via a two-step method. Hard segments consisted of 4,4′-diphenylmethane diisocyanates and the bio-based 1,4-butanodiol (used as a chain extender and used to control the [NCO]/[OH] molar ratio). The impacts of the structure of flexible segments, the amount of each type of prepolymer, and the [NCO]/[OH] molar ratio on the chemical structure and selected properties of the TPUs were verified. By regulating the number of flexible segments of a given type, different selected properties of TPU materials were obtained. Thermal analysis confirmed the high thermal stability of the prepared materials and revealed that TPUs based on a higher amount of prepolymer synthesized from PO3G2700 have a tendency for cold crystallization. An increase in the amount of PO3G1000 at the flexible segments caused an increase in the tensile strength and decrease in the elongation at break. Melt flow index results demonstrated that the increase in the amount of prepolymer based on PO3G1000 resulted in TPUs favorable in terms of machining.

The Effect of Fluid Velocity on the Diffusion of Trimethylene Glycol through a Reverse Osmosis Membrane in Microchannel -X

The study aims to observe the diffusion process which is influenced by different velocity and fluid concentrations. Using a microfluidic system and the diffusion process through a reverse osmosis membrane. The research was carried out by flowing fluid into the microchannel. The diffusion process is known by measuring and analyzing the density of liquid waste aquades-trimethylene glycol. The results showed the amount of diffusion through the membrane was influenced by flow velocity and fluid concentration. this is because the velocity of the flow produces pressure on the wall so that it pushes the fluid to diffuse through the membrane.

Electron paramagnetic resonance of sonicated powder suspensions in organic solvents

The chemical effects of the acoustic cavitation generated by ultrasound translates into the production of highly reactive radicals. Acoustic cavitation is widely explored in aqueous solutions but it remains poorly studied in organic liquids and in particular in liquid/solid media. However, several heterogeneous catalysis reactions take place in organic solvents.Thus, we sonicated trimethylene glycol and propylene glycol in the presence of silica particles (SiO2) of different sizes (5–15 nm, 0.2–0.3 µm, 12–26 µm) and amounts (0.5 wt% and 3 wt%) at an ultrasound frequency of 20 kHz to quantify the radicals generated. The spin trap 5,5-dimethyl-1-pyrrolin–N-oxide (DMPO) was used to trap the generated radicals for study by electron paramagnetic resonance (EPR) spectroscopy. We identified the trapped radical as the hydroxyalkyl radical adduct of DMPO, and we quantified it using stable radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as a quantitation standard. The concentration of DMPO spin adducts in solutions containing silica size 12–26 µm was higher than the solution without particles. The presence of these particles increased the concentration of the acoustically generated radicals by a factor of 1.5 (29 µM for 0.5 wt% of SiO2 size 12–26 µm vs 19 µM for 0 wt%, after 60 min of sonication). Ultrasound produced fewest radicals in solutions with the smallest particles; the concentration of radical adducts was highest for SiO2 particle size 12–26 µm at 0.5 wt% loading, reaching 29 µM after 60 min sonication. Ultrasound power of 50.6 W produced more radicals than 24.7 W (23 µM and 18 µM, respectively, at 30 min sonication). Increased temperature during sonication generated more radical adducts in the medium (26 µM at 75 °C and 18 µM at 61 °C after 30 min sonication). Acoustic cavitation, in the presence of silica, increased the production of radical species in the studied organic medium.

Green Recycling of Poly(ethylene terephthalate) Waste as Corrosion Inhibitor for Steel in Marine Environment

Green recycling of poly(ethylene terephthalate) plastic waste, in this respect, PET waste was subjected to de polymerization process with tri methylene glycol (1,3-propandiol) in the presence of manganese acetate (1.0 % w/w to the total Wight of the reactants) as trans esterification catalyst, the product is Bis-(3-hydroxy-propyl)-terephthalate, BHPT, as a non-ionic surfactant was separated and characterized by FT-IR and 1HNMR and evaluated as corrosion inhibitor for carbon steel alloy in artificial marine environment using chemical and electrochemical techniques. Effect of inhibitor concentrations and reaction temperature were studied. The chemical techniques used in this work are gravimetric, thermometric and atomic absorption spectroscopy(AAS), whereas the electrochemical techniques are open circuit potential, potentiodynamic polarization. The corrosion inhibition efficiency increases with increasing inhibitor concentrations and decreased by rising temperature. The maximum corrosion inhibition efficiency 96.5% was afforded using 300 ppm of the used inhibitor derived from plastic waste. Potentiodynamic polarization curves indicate that the used system act as mixed inhibitor. The data of AAS show that the iron(iii) ions Fe+3 concentrations were decreased by increasing inhibitor concentration. All the used techniques are in good agreement to each other (±2 %) and shows that the used drug acts as green corrosion inhibitors for steel in marine environment.

Remarkable diastereomeric effect on thermoresponsive behavior of polyurethane based on lysine and tartrate ester derivatives.

This study describes the long-distance diastereomeric effect on thermoresponsive properties in water-soluble diastereomeric polyurethanes (PUs) composed of an l-lysine ethyl ester diisocyanate and a trimethylene glycol l-/d-tartrate ester, which have differences in spatial arrangements of the ethyl esters in the mirror image. The PUs based on l-lysine and l-/d-tartrate ester, named l-PU and d-PU, were synthesized with various number average molecular weights from 4700 to 13 100. In turbidimetry, l-PU showed a steep phase transition from 100%T to 0%T within about 10 °C at 4 g L−1, whereas d-PU did not change completely to 0%T transmittance even at 80 °C at 4 g L−1. In addition, the thermoresponsive properties of l-PU were less affected by concentration than those of d-PU. This long-distance diastereomeric effect on thermoresponsive behavior between l-PU and d-PU appeared in common among 6 samples with 4700 to 13 100 number average molecular weight. In the dynamic light scattering experiments at each transmittance, the hydrodynamic diameter (Dh) of l-PU increased up to 1000 nm, while the Dh of d-PU remained almost at 200–300 nm. The C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> O stretching vibration of FT-IR spectra showed that d-PU has more hydrogen-bonded ester groups than L-PU. Thus, we speculated that the difference in the retention of polymer chains in the micelle to promote intermicellar bridging generates the long-distance diastereomeric effect.

Green Synthesis for Nonionic Surfactants from Poly(etheleneterphthalate) Plastic Waste

ABSTRACT Efficient solvent free green glycolysis for Polyethylene Terephthalate plastic waste, in this respect, PET waste was subjected to depolymerization process with trimethylene glycol (1,3-propandiol) in the presence of manganese acetate as trans esterification catalyst, the product is Bis-(3-hydroxy-propyl)-terephthalate, BHPT, as a non-ionic surfactant was separated and characterized by FT-IR and 1HNMR, The surface properties were studied by measuring the surface tension at different concentrations and temperatures. The surface tension, critical micelle concentration (CMC), and surface activities were determined. The surface parameters such as surface excess concentration (rmax), the area per molecule at interface (Amin)and the effectiveness of surface tension reduction ( πCMC ) were determined from the adsorption isotherms of the prepared surfactant. The thermodynamic data for the micellization and adsorption process were calculated and discussed.

Structure and Morphology of Thermoplastic Polyamide Elastomer Based on Long-Chain Polyamide 1212 and Renewable Poly(trimethylene glycol)

Novel biobased thermoplastic polyamide elastomers (TPAEs) were synthesized using a long-chain polyamide 1212 (PA1212) oligomer and 100% renewably resourced poly(trimethylene glycol) (PPDO) via a facile “two-step” melt polycondensation. The TPAEs are lightweight, with a density of 1.04∼1.05 g cm–3. The structure and morphology of the TPAEs with high biocontent were investigated by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), atomic force microscopy (AFM), transmission electron microscopy (TEM), and dynamic thermomechanical analysis (DMA). The results show that the new biobased TPAEs have a clearly microphase-separated structure comprising quite low crystalline PA1212 segments and an amorphous PPDO segment at room temperature. The spherical rigid PA1212 domains for PA624-PPDO with a diameter of about 100 nm can well disperse in the amorphous PPDO phase. Moreover, the rigid PA1212 segments mutually interconnect with the increasing molecular weight of the PA1212 oligomer, and the typical PA1212 spherulites about 200 nm with lamellae structures have been found in PA2200-PPDO, filled with amorphous PPDO in the interlayer. Since the structure and morphology characteristics, the storage modulus (E′) of TPAEs quickly decreases from about 3000 MPa in a glassy state to 400 MPa in a rubbery state. Furthermore, long-chain PA1212 segments contribute to the outstanding thermal stability; i.e., the initial decomposition temperatures of all TPAEs are over 360 °C. The novel biobased TPAEs with good low-temperature elastic, high elastic recovery, and good thermally stable properties are expected to have potential applications in CO2 separation and breathable dressing.

Genotoxin Effect of Composite Resin

At this moment composite resin is the most widely used material for dental restoration. The content of the resin is a mixture of monomer bisphenol A glycidyl methacrylate (Bis-GMA), trimethylene glycol dimethylmethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) and special particle fillers made of radioopaque glass. Many studies have been conducted to study the biocompatibility of composite resin, especially the cytotoxicity and genotoxicity test. Genotoxicity tests that are often carried out are comet test for DNA damage protection and micronuclei test for protection of genome damage. The monomer content of composite resins can have a genotoxic effect.

Ispitivanje mehaničkih svojstava akrilatnih kompozitnih materijala sa različitim AL2O3 ojačanjima brazilskim testom

Composite materials based on UV-curing acrylates and various alumina-based reinforcements represent material that is suitable for the use in dentistry, but also in other areas. Composites were made using four different types of reinforcement of chemically very similar compositions, but different size and morphologies. In order to monitor the mechanical properties of the composite material, samples were made in the form of discs of defined dimensions suitable for polymerization under UV light. The subject of this study is the examination of the mechanical properties of the Bis-GMA (Bisphenol A glycidyl methacrylate)/TEGDMA (trimethylene glycol dimethacrylate) photopolymer composite material as a matrix. The reinforcements were in the form of commercial nanoparticles and alumina whiskers and their influence on mechanical properties were compared with the influence of synthesized alumina particles doped with iron oxide synthesized sol-gel technique. In order to test the mechanical properties of composite materials, the Brazilian Tests and the testing of the microhardness of samples were employed.

Red fluorescent ZnO nanoparticle grafted with polyglycerol and conjugated RGD peptide as drug delivery vehicles for efficient target cancer therapy

In the field of modern nanomedicine, ZnO nanoparticles were considered as an emerging candidate for drug delivery because of their inherent biocompatibility and stability. However, the poor dispersibility in a physiological medium obstructed their clinic applications. In this paper, the red fluorescence ZnO nanoparticles were synthesized, using a facile chemical method of polyol in boiling trimethylene glycol (TREG) with zinc acetate. The as-synthesized ZnO nanoparticles were first time grafted with PG layer through ring-opening polymerization of glycidol (ZnO-PG). As calculated from the TGA data, the weight ratio of the grafted PG was about 68 wt%. Then, the ZnO-PG engineered to conjugate with arginine-glycine-aspartate (RGD) peptide by stepwise organic reactions. Finally, anticancer drugs Doxorubicin hydrochloride (DOX) was immobilized on ZnO-PG-RGD (approximately 21.8 ± 0.9 nm) to form ZnO-PG-RGD/DOX. The drug release percentage reaches 70.6% within 48 h under pH 5.2, which was more than 3-fold higher than that pH 7.4. The properties of ZnO nanoparticles and its derivatives were detected by power XRD, TEM, EDS, FTIR, TGA, DLS, Zeta potential and UV. The grafted PG layer not only largely enhanced the dispersibility, but also inhibited ZnO nanoparticles from the uptake by U87MG and Hela cells. In contrast, ZnO-PG-RGD was selectively taken up by U87MG, not Hela cells, demonstrating an obvious targeting property. When ZnO-PG-RGD/DOX was used, U87MG cells showed specificity damaged compared with Hela cells. Thus, functionalized ZnO nanoparticle was a promising nanomaterial in cancer theranostics.

Thermoplastic Polyurethane Elastomers with Aliphatic Hard Segments Based on Plant‐Oil‐Derived Long‐Chain Diisocyanates

AbstractNovel plant‐oil‐derived long‐chain (C19 and C23) α,ω‐diisocyanates, optionally in combination with the corresponding long‐chain diols, provide entirely aliphatic hard segments in segmented thermoplastic polyurethane elastomers (TPUs), with carbohydrate‐based poly(trimethylene glycol) soft segments. Compared to materials based on a mid‐chain monomer analog, phase separation is higher due to an increased flexibility of the aliphatic segments. Although melting points are slightly lower than for HDPE, the long‐chain TPU's solid‐state structure is still dominated by hydrogen‐bonding.

Boronic acid and boronic ester containing polyoxometalates.

Three organoboron functionalized polyoxometalates have been synthesized using Schiff base chemistry including a boronic acid, its methyl ester and its trimethylene glycol ester. The compounds have been characterized in the solid state by single crystal diffraction (XRD), FT-IR and elemental analysis and in solution using 1H NMR spectroscopy.

Conformational Identification and Phase Transition Behavior of Poly(trimethylene 2,6-naphthalate) α-Form Modification

Poly(trimethylene 2,6-naphthalate) (PTN) is one of the 1,3-propanediol (PDO)-based aromatic polyesters which has potential applications for special barrier films and packaging due to its excellent oxygen and carbon dioxide gas barrier property. In this work, we investigated the chain conformation and phase transition behavior of poly(trimethylene 2,6-naphthalene) (PTN) α-form crystal with synchrotron wide- and small-angle X-ray scattering (WAXS and SAXS), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and differential scanning calorimetry (DSC) methods. ATR-FTIR results showed that the infrared bands at 1327 and 987 cm–1 were sensitive to PTN α-form crystalline phase and were assigned to trans conformers of trimethylene group, whereas the infrared bands at 1357 and 1372 cm–1 were sensitive to PTN β-form crystalline phase and were assigned to gauche conformers of the trimethylene group. The results showed that the conformation of trimethylene glycol residue in PTN α-form cr...

Recent Developments in Heat Transfer Fluids Used for Solar Thermal Energy Applications

Solar thermal collectors are emerging as a prime mode of harnessing the solar radiations for generation of alternate energy. Heat transfer fluids (HTFs) are employed for transferring and utilizing the solar heat collected via solar thermal energy collectors. Solar thermal collectors are commonly categorized into low temperature collectors, medium temperature collectors and high temperature collectors. Low temperature solar collectors use phase changing refrigerants and water as heat transfer fluids. Degrading water quality in certain geographic locations and high freezing point is hampering its suitability and hence use of water-glycol mixtures as well as water-based nano fluids are gaining momentum in low temperature solar collector applications. Hydrocarbons like propane, pentane and butane are also used as refrigerants in many cases. HTFs used in medium temperature solar collectors include water, waterglycol mixtures – the emerging “green glycol” i.e., trimethylene glycol and also a whole range of naturally occurring hydrocarbon oils in various compositions such as aromatic oils, naphthenic oils and paraffinic oils in their increasing order of operating temperatures. In some cases, semi-synthetic heat transfer oils have also been reported to be used. HTFs for high temperature solar collectors are a high priority area and extensive investigations and developments are occurring globally. In this category, wide range of molecules starting from water in direct steam generation, air, synthetic hydrocarbon oils, nanofluid compositions, molten salts, molten metals, dense suspension of solid silicon carbide particles etc., are being explored and employed. Among these, synthetic hydrocarbon oils are used as a fluid of choice in majority of high temperature solar collector applications while other HTFs are being used with varying degree of experimental maturity and commercial viability – for maximizing their benefits and minimizing their disadvantages. Present paper reviews the recent developments taking place in the area of heat transfer fluids for harnessing solar thermal energy.

Development of complex approach to the synthesis of trimethylene carbonate as a monomer for biodegradable polymers

With the aim of production of polymers for medicine a new preparation method was developed for trimethylene carbonate based on transesterification with trimethylene glycol of dialkyl carbonates obtained without the use of phosgene. As initial reagents alkylene carbonates or polycarbonates and titanium alkoxides can be utilized. The advantages of this approach consist in obtaining some additional useful substances and the possibility of reprocessing polycarbonate wastes.

Formation of mesomorphic domains associated with dimer aggregates of phenyl rings in cold crystallization of poly(trimethylene terephthalate)

During the cold crystallization of poly(trimethylene terephthalate), PTT, multistage preordering activities associated with hierarchically structural evolution and origin of mesomorphic domains were investigated with time-resolved Fourier transform infrared (FTIR), photoluminescence (PL) and dielectric spectra (DS), and simultaneous small- and wide-angle X-ray scattering (SAXS/WAXS). The observed fluorescent emission at 390 nm and an absorption band at 874 cm−1 associated with the CH out-of-plane bending mode of the phenyl rings indicate that the ground-state dimers resulting from the phenyl rings of PTT chains via π–π interactions are formed in supercooled amorphous liquids. The time dependences of the increase of the fluorescent intensities, the wavenumber shift from 874 to 872 cm−1, the conformational transformation of the trimethylene glycol units from trans to gauche, the dynamic α-to-α′ transition of the dielectric loss and the structural parameters reveal that the dimer aggregation accompanying a locally nematic-like orientation induced large phase-separated mesomorphic domains (over several tens of nanometers); nucleations of nanograin type (over several nm) subsequently formed within the mesomorphic domains after the conformational transformation form trans to gauche for the cold crystallization at 50 °C. Herein, we propose a preordering mechanism of cold crystallization in which the π–π interactions among the dimers serve as ordering bonding forces to drive intermolecular cooperativity before intramolecular changes of conformation, and the dimer aggregation triggers the phase-separated mesomorphic domains before the growth of crystalline nanograins (non-lamellar crystals). As distinct from the hierarchical structure of nanograins within mesomorphic domains, the formation of lamellar crystallites within spherulites without undergoing the dimer aggregation were observed form the melt crystallization at 200 °C.

Synthesis of Octopus Type Trimethylene Glycol β-D-glucopyranosides

ABSTRACT The octopus type oligo-hydroxypropylene glycol β-D-glucopyranosides were successfully synthesized in this studies: the sterospecific compound of allyl 2, 3, 4, 6-tetra-O-acetyl-β-D-glucopyranosides (1) was deacetylated with NaOMe in MeOH lead to allyl-β-D-glucopyranoside (2) which was perallylated and followed by hydroboration and subsequent oxidation afforded (3-hydroxy-propyl) 2, 3, 4, 6-tetraO(3-hydroxy-propyl)- β-D-glucopyranoside (4). As a result, not only allylpropylene glycol β-D-glucopyranosides (5, 7, and 9) but also hydroxypropylene glycol β-D-glucopyranosides (6, 8, and 10) were synthesized by repeated sequential perallylation followed by hydroboration/oxidation. Keywords : hydroboration/oxidation, perallylation, oligo-hydroxypropylene glycol β-D-glucopyranosides 1. INTRODUCTION Carbohydrates are naturally occurring abund-ant compounds that have been widely studied for a plethora of applications (Hanessian, 1983; Scott, 1994; Middleton et al., 1993). Of parti-cular interest has been their use as polyfunctional molecules for the design and/or synthesis of car-bohydrate-centered multivalent glycoclusters and glycodendrimers (Lindhorst et al., 1998; Lind-horst et al., 2001; Lindhorst et al., 2006). Most of them are based on a multi-step synthesis con-sisting of oligo-glycosylation in order to achieve a uniform O-hydroxy-spacer, such as ethylene or propylene glycol not only in the 2, 3, 4, 6-tetra hydroxy groups but also at the α-anomeric po-sition, turning them into carbohydrate-centered cluster glycosides (Lindhorst et al., 1998; Lind-horst et al., 2001; Lindhorst et al., 2006).Thus, it became our goal to attempt the syn-thesis of the exhaustive glycosylation of octopus type β-D-glucopyranosides. This could provide us with a great potential opportunity of a novel class of high-molecular weight monosaccharide mimetics, which could possibly be adapted for the generation of various spacers with different

Theoretical Study of Hydrogen Bond Formation in Trimethylene Glycol-Water Complex

A detailed quantum chemical calculation based study of hydrogen bond formation in trimethylene glycol- (TMG-) water complex has been performed by Hatree-Fock (HF) method, second-order Møller-Plesset perturbation theory (MP2), density functional theory (DFT), and density functional theory with dispersion function (DFT-D) using 6-31++G(d,p) basis set. B3LYP DFT-D, WB97XD, M06, and M06-2X functionals are used to capture highly dispersive hydrogen bond formation. Geometrical parameters, interaction energy, deviation of potential energy curve of hydrogen-bonded O–H from that of free O–H, natural bond orbital (NBO), atom in molecule (AIM), charge transfer, and red shift are investigated. It is observed that hydrogen bond between TMG and water molecule is stronger in case of TMG acting as proton donor compared to that of water acting as proton donor, and dilute TMG solution would inhibit water cluster formation.