Abstract  Pesticides incorporated into granules are a popular formulation option. Ideally, a granule should offer high liquid holding capacity, high resistance to attrition, low dust and chemical inertness. Clay granules offer a formulator all of the above benefits except, on occasion, chemical inertness. Clays possess chemical activity arising From acid sites associated with the clay surface. While this is not always a problem, in some instances a deactivator (e.g. dipropylene glycol) is incorporated into the formulation to counteract the surface activity of the clays. In this paper, a clay granule that has been processed to lower surface activity is described. The physical characteristics of the new granule are contrasted with clay granules processed in the traditional manner. The stability of two phosphate ester pesticides on the new granule is presented. In one instance, the new granule results in a decrease in the amount of deactivator needed for a stable formulation. In the other instance, the new granule results in a formulation that is stable with no deactivator.

Abstract  For improving the finishing performances of complicated three-dimensional coated wood products (e.g., furniture) with some shadow zones in the absence of ultraviolet (UV) light, resulting in incomplete curing of UV coatings, the aim of this study was to investigate the characteristics and effects of curing process on the properties of epoxy acrylate UV/PU dual-cured resin for wood coatings when compared with traditional UV and polyurethane (PU) coatings. The epoxy acrylate oligomer was synthesized for providing a double bond of acryloyl group and a secondary hydroxyl group. The UV/PU dual-cured coating was formulated with epoxy acrylate resin/tripropylene glycol diacrylate (TPGDA) monomer by the weight ratio of 80/20, 3% dosage of benzil dimethyl ketal as a photoinitiator, and the NCO/OH mole ratio of 1.0. The aromatic polymeric diphenylmethane diisocyanate was used as a hardener. The films of the dual-cured coating, obtained from UV-cured or room temperature-cured process, showed an excellent tensile strength, elongation at break, impact resistance, and lightfastness when compared with traditional UV and PU coatings; especially, the adhesion of UV/PU dual-cured coating by UV-cured process was better than that of traditional UV coating. It can therefore be concluded that the epoxy acrylate oligomer-based dual-cured coating could readily be used for complicated wood products finishing. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 2197-2202, 2010

Abstract  Stepwise and concerted mechanisms for the formation of mono- and dipropylene glycol over ZSM-5 zeolite were investigated. For the calculations, a T128 cluster model of zeolite was used with a QM/QM scheme to investigate the reaction mechanism. The active inner part of zeolite was represented by a T8 model and was treated at the DFT (BP86) level, including D3 Grimme dispersion, and the outer part of the zeolite was treated at the DFTB level. The solvent effects were taken into account by including explicitly water molecules in the cavity of the zeolite. The Gibbs energies were calculated for both mechanisms at 70 degrees C. In the case of the stepwise mechanism for the monopropylene glycol formation, the rate-limiting step is the opening of the epoxide ring. The activation energy for this process is 35.5 kcal mol(-1), while in the case of the concerted mechanism the rate-limiting step is the simultaneous ring opening of the epoxide and the attack by a water molecule. This process has an activation energy of 27.4 kcal mol(-1). In the case of the stepwise mechanism of the dipropylene glycol formation, the activation energy for the rate-limiting step is the same as for the monopropylene glycol formation, and in the case of the concerted mechanism, the activation energy for the rate-limiting step is 30.8 kcal mol(-1). In both cases (mono- and dipropylene glycol formation), the concerted mechanism should be dominant over the stepwise one. The barrier for monopropylene glycol formation is lower than that for dipropylene glycol formation. Consequently, our results show that the formation of the monopropylene glycol is faster, although the formation of dipropylene glycol as a byproduct cannot be avoided using this zeolite.

Abstract  Thin polymer films were prepared under ultraviolet radiation with a triacrylated aliphatic urethane oligomer that was diluted with reactive monomers such as N-vinyl pyrrolidone and tripropylene glycol diacrylate. These films were characterized. The effect of incorporation of a minute amount (>0.15%) of a titanium-pyridine complex and its ligands on the characterization of these polymers was investigated. Cotton and jute yarns were treated with the solutions containing these materials under the UV radiation. The change in tensile properties of the treated natural polymers (cotton and jute) was evaluated, and it was found that the titanium-pyridine-based complex substantially enhanced the tensile strengths (tenacity) for bath cotton and jute. (C) 1999 John Wiley & Sons, Inc.

Abstract  The excess molar volume (V(m)(E)), ultrasonic speed (u), and dynamic viscosity (eta) have been measured in dipropylene glycol dimethyl ether + butylamine, dibutylamine, and tributylamine across their entire composition ranges at 298.15 K and atmospheric pressure. The density values derived from the excess molar volumes were converted to molar volumes (V) which are combined with the speed of sound to obtain estimates of the product K(S,m), and their excess counterparts K(S,m)(E). in all mixtures the excess molar volumes are negative and symmetric across the entire composition range. The K(S,m)(E) values are positive for all mixtures. The deviation of the speeds of sound u(D) from their ideal values u(id) in-an ideal mixture were also calculated for all measured mole fractions. Viscosities have also been measured for mixtures of dipropylene glycol dimethyl ether and butylamine, dibutylamine, or tributylamine at the same temperature. From the experimental data, the deviation in the viscosity eta from Sigma x(i) ln eta(i) and excess energies of activation for viscous flow (Delta G*(E)) have been derived for all systems. The Flory theory of mixtures provides a useful basis for a quantitative interpretation of the viscosity results. The theoretical values of molar isentropic compressibility (K(S,m)) and of speed or sound (u) have been estimated using the Prigogine-Flory-Patterson (PFP) theory with the van der Waals (vdW) potential energy model and the results have been compared with experimental values.

Abstract  In the past, these laboratories have studied adducts of neutral phosphonate esters with various metal salts, and polymeric metal complexes derived from reactions of the neutral ester with metal halides(2). For example, diisopropyl methylphosphonate [dimp; (i-PrO)2MeP = O] yields adducts with 3d metal perchlorates(3), while upon reaction with SnX4 (X = Cl, Br or I) it produces initially adducts of the Sn(dimp)2X4 type(4), which react further with the mother liquor at elevated temperatures (> 100-degrees-C), yielding, successively, Sn(OOPMe(OPr-i))2X2 and Sn(O3PMe)2 polymeric complexes with concomitant formation of i-PrX(5,6). We recently became interested in studying the corresponding reactions of the same metal salts with a more complex neutral phosphonate ester with long-chain substituents, such as Weston Chemical's CP-1 {bis(dipropyleneglycol) 1-hydroxy-2,2,2-trichloroethyl-phosphonate} (L; 1). Accordingly, research was undertaken in this direction, and our progress is reported in this communication. [GRAPHICS]

Abstract  Halato-telechelic polyurethane-ureas were synthesized from divalent metal salts of p-aminobenzoic acid, 4,4'-diaminodiphenylmethane (4,4'-methylenedianiline, MDA), dialkylene glycols, and 2,4-toluylene diisocyanate (TDI). As the divalent metal, Mg and Ca were used, and diethylene glycol and dipropylene glycol were the glycols used. The halatotelechelic polyurethane-ureas obtained showed better solubilities in dimethylformamide (DMF) and dimethylsulfoxide (DMSO) than previously reported halato-telechelic polyureas from the metal salts, MDA, and TDI. The reduced viscosities of the polyurethane-ureas in DMF and DMSO were very low at very low concentrations but increased as the concentration increased. The increase was higher in DMF having lower dielectric constant, due to lower depression of ionic association. Introducing the metal into the urethane-urea backbone resulted in a considerable decrease in decomposition temperature. In dynamic mechanical property measurements, they exhibited no sharp decrease in relative shear modulus and no peak of tan-delta, probably due to aggregation of ionic groups in the polymer main chain.

Abstract  The excess volume V-E, speed of sound u, and viscosity eta have been measured for the binary mixtures of dipropylene glycol monobutyl ether with butylamine, dibutylamine, and tributylamine across their entire composition ranges, at a temperature of 298.15 K and atmospheric pressure. The density values derived from the excess molar volumes were converted to molar volumes, V, which are combined with the speed of sounds to obtain estimates of the product K-S,K-m, and their excess counterparts K-S,m(E). The deviation of the speeds of sound u(D) from their ideal values u(id) in an ideal mixtures were calculated for all estimated values of mole fraction x(1). Viscosities have also been measured for mixtures of dipropylene glycol monomethyl ether and butylamine, dibutylamine, or tributylamine at the same temperature. From the experimental data, deviations in viscosity (Delta ln eta) and excess energies of activation for viscous flow (Delta G*(E)) have been derived for all systems. The Flory theory of mixtures provides a useful basis for a qualitative interpretation of the viscosity results. The theoretical values of molar isentropic compressibility of K-S,K-m and of speed of sound u have been calculated using the Prigogine-Flory-Patterson (PFP) theory with the van der Waals (vdW) potential energy model and the results have been compared with experimental values. (c) 2005 Elsevier Ltd. All rights reserved.

Abstract  The effect of dipropyleneglycol dibenzoate, a plasticizer, on the glass-transition temperature (T-g) of poly(vinyl acetate) was studied using deuterium solid-state NMR and modulated differential scanning calorimetry (MDSC) from 0 to 20% plasticizer content. Quadrupole-echo H-2 NMR spectra were obtained for methyl deuterated PVAc-d(3) samples with different plasticized amounts. The T-g's of different plasticized samples were determined from NMR as the temperatures at which the deuterium powder patterns collapsed. It was found that the T-g's decreased by approximately 6 degrees C for every 5% increment in the plasticizer content and that the trends in the NMR-determined T-g's, that is, T-g(NMR), were consistent with those determined by modulated differential scanning calorimetry (MDSC). The T-g(NMR) values were about 36 degrees C above those of the T-g(DSC) values. This difference in the T,'s was due to the different time scales of the two experiments which could be accounted for on the basis of time-temperature superposition principles. The experimental NMR line shapes were fitted using a set of simulated spectra generated from the MXQET Simulation program. The spectra were based on a model of nearest-neighbor jumps on a truncated icosahedron (soccer ball). The resulting average correlation times were also found to fit a time-temperature superposition with the same parameter. While the T-g was decreased by the amount of plasticizer, it was found that the breadth of the transitions from either the NMR line shapes or the MDSC thermograms did not seem to change much with the amount of added plasticizer.

Abstract  A difunctional acrylate of ricinoleic acid amide (COEDA) was synthesized from castor oil, which was non-irritant, odorless and capable of fast polymerization. Cross-linked networks were prepared by photo polymerization of the COEDA monomer as well as with varying amount of reactive diluents namely tripropylene glycol diacrylate (TPGDA) and trimethylol propane triacrylate (TMPTA) with the aim of modifying the curing and viscoelastic characteristics of the networks. Conversion as well as rate of conversion of COEDA copolymers enhanced with diluents percentage. Cure kinetics indicated an auto-accelerated process in which the rate constant increased with increasing amount of diluents. Storage modulus and glass transition temperature of UV-cured films were determined by DMTA. Films containing varying amount of TPGDA showed very close T-g-values where as those with increasing amount of TMPTA exhibited higher values of T-g. (c) 2007 Published by Elsevier B.V.

Abstract  The kinetics of poly(ethylene terephthalate) (PET) glycolysis by diethylene glycol (DEG), dipropylene glycol (DPG), glycerol (Gly) and mixtures of these glycols have been studied with two experimental procedures: uncatalysed at 220 degrees C and catalysed at 190 degrees C. An experimental device was set up allowing the isothermal kinetics to be monitored. A precise initial reaction time was obtained by separately warming the glycol and the polyester at the temperature of reaction before mixing them.

The reactivity order of different glycols varies according to the conditions of temperature and catalysis. Schematically, the global reactivity does depend not only on the chemical reactivity of the glycol but also on its physico-chemical properties: ability to solvate the solid polyesters and polarity of the reaction mixture. Attempts to find synergic effects failed for almost all mixtures, except the mixture DPG + Gly in which the PET is digested more quickly than in pure DPG or Gly. (c) 2006 Elsevier Ltd. All rights reserved.

Abstract  To increase the photopolymerization rate and improve the properties of UV coatings, polymerizable silica hybrid nanoparticles with tertiary amine structure were prepared. Organic compound with isocyanate group was first grafted onto the surface of nanosilica by reaction of nanosilica with isophorone diisocyanate, then the nanosilica bearing isocyanate group reacted with N,N-di(3-propionic acid, 1,4,7-trimethyl-3,6-dioxaoctane-8-yl acrylate, ester) ethanolamine synthesized from tripropylene glycol diacrylate and ethanolamine. The preparation was characterized by (1)H nuclear magnetic resonance (NMR) and Fourier transform infrared spectrometry (FT-IR). Thermogravimetric analysis (TGA) showed that the organic compounds grafted onto the silica decomposed from 256 degrees C to 650 degrees C and the grafting percentage based on nanosilica was 105%. The morphology analysis of nanosilica and modified silica by field-emission scanning electron microscopy (FE-SEM) indicated that the silica kept nanosized scale after modification, while the nanosilica dispersion was improved and formation of agglomerates unlikely. Determination of viscosities of coatings with modified nanosilica, it was found that viscosities of the coatings decreased in comparison with the viscosities of coatings with unmodified nanosilica. Compared with pure organic coating, the photopolymerization rate of coatings were faster when modified nanosilica was used from 1 wt% to 5 wt%, but slower when the loadings of modified nanosilica was 7 wt% because co-initiating effects of tertiary amine compound grafted on nanosilica counterbalanced the effects of UV scattering by silica on photopolymerization rate. The hardness and abrasive resistance of cured films also increased and improvement degree was different when the various amounts of modified nanosilica were used. (C) 2011 Elsevier B.V. All rights reserved.

Abstract  A novel hybrid photoinitiator for visible light photopolymerization, (eta(6)-3-benzoyl-4-chlorodiphenylamine) (eta(5)-cyclopentadienyl) iron hexafluorophosphate (Fc-NBP), was synthesized and studied. Its absorption in the UV and visible light regions showed much stronger activity than those of either the commercialized cationic photoinitiator 1-261 or the conventional free radical photoinitiator benzophenone, especially above wavelengths of 350 nm. When exposed to visible light, the photoinitiator under study initiates both cationic polymerization and radical polymerization. The photoinitiator's abilities in the photopolymerization of acrylates and epoxides were evaluated by near infrared (NIR) spectroscopy. The results from NIR clearly indicate that Fc-NBP exhibited high efficiency in photopolymerizing acrylate monomers. In the same lamp, however, benzophenone showed no photoinitiating ability. The photopolymerization rate of the diglycidyl ether of the bisphenol-A epoxy (DGEBA) oligomer was found to be slower than that of acrylates when using Fc-NBP as the photoinitiator. This study shows that the polymerization of epoxide DGEBA can be speeded up by adding a photosensitizer benzoyl peroxide (BPO), but BPO and tertiary amines do not affect the free radical photopolymerization of tripropylene glycol diacrylate (TPGDA). We conclude by providing a possible photoinitiation mechanism. (C) 2010 Elsevier B.V. All rights reserved.

Abstract  Thermal techniques, such as differential scanning calorimetry (DSC), thermogravimetry (TG), derivate of TG curve, differential thermal analysis, and non-thermal techniques such as fourier transform infrared (FTIR) spectroscopy and X-ray diffractometry (XRD) were used to evaluate the possible interactions between hydroquinone (HQ) and excipients commonly used in semi-solid pharmaceutical forms. The DSC curve of HQ showed a sharp endothermic event between 173 and 179 A degrees C indicating melting point. No evidence of interaction was observed between HQ and cetyl alcohol (CA), cetostearyl alcohol (CTA), disodium ethylenediaminetetraacetate , and decyl oleate. However, based on the thermoanalytical trials, a physical interaction was suspected between HQ and dipropylene glycol (DPG), glycerin (GLY), hydroxypropyl methylcellulose (HPMC), imidazolidinyl urea (IMD), methylparaben (MTP), and propylparaben (PPP). The FTIR results show that for DPG, GLY, HPMC, MTP, and PPP, there were no chemical interactions with HQ at room temperature, but the heating promotes interaction between HQ and HPMC. The FTIR spectra of HQ/IMD show the chemical interaction at room temperature, which was also observed with heating. The XRD results of mixtures between HQ and DPG, HPMC, IMD, MTP, and PPP indicate no interaction between these substances at room temperature, but the heating modifies the HQ crystallinity in these mixtures. All of these methods showed incompatibility between HQ and the excipient IMD.

Abstract  The real-time Brillouin scattering study using a nonscanning Fabry-Perot interferometer (NSFPI) is reported on the acoustic properties of glass-forming tripropylene glycol monomethyl ether (TPGME). Due to the very short acquisition time of NSFPI, Brillouin spectra of TPGME from liquid to glassy phases have been successfully measured within 4 h, which is much shorter than that of conventional scanning-type Fabry-Perot interferometers. The deviation of the sound velocity from the low-frequency limiting value and the increase of the central peak intensity in addition to the Brillouin linewidth indicate a coupling of some structural relaxation to the acoustic waves. Based on a simple Debye approximation, it was shown that the relaxation process probed by Brillouin scattering obeys the Arrhenius law with an activation energy of about 3.1 kcal/mol and a preexponential factor of 5.9 X 10(-14) s. (C) 2003 Elsevier Science B.V. All rights reserved.

Abstract  Twelve different formulations were developed with aliphatic backbone-based urethane acrylate oligomer (Ebecry-264) in combination with a number of monomers like N-vinyl pyrrolidone (NVP), tripropylene glycol diacrylate (TPGDA), plasticizer, diallyl phthalate (DP), and antibubling agent methyl ethyl ketone (MEK), along with a photoinitiator Irgacure 184. Some additives and coadditives, such as calcium carbonate, urea, copper, and acrylamide, were incorporated into these formulations to study their effects on the physical and mechanical properties of pendulum hardness, gel content, and tensile strength and elongation at break of the films produced under UV radiation with these formulated solutions. These formulations were applied on jute fabrics (Hessian cloth) and cured under UV radiation. The improvement of various physicomechanical properties, such as tensile strength, elongation at break, and water resistivity of the treated jute fabrics was determined. The best formulation was evaluated.

Abstract  Controlled and patterned variation of refractive index (wavefront) across a lens surface was obtained via the use of "phase mask". Gradient interpenetrating network was selected to screen the acrylate and epoxy monomer to obtain necessary refractive index change over the lens surface. The best photoinitiator system was determined to give a stable and transparent wavefront as a mixture of 2 wt% Irgacure 250 (I 250), 1 wt% Isopropylthoxanthone (ITX) and 0.5 wt Irgacure 184 (I 184). It is found that a dipropylene glycol diacrylate (SR 508) and a triethylene glycol dimethacrylate (TGDM) improved the stability of the transparent wavefront because of higher Tg of the network. Haze problem, a consequence of diffusion of one monomer to other network because of the rate differences, was eliminated with IPN composed of TGDM (an acrylate with slow polymerization rate) and bis (3,4-epoxy cyclohexylmethyl) adipate (BECMA, an epoxy with fast polymerization rate). A high refractive index additive, bromonaphthalene, resulted the best wavefront with lens power when incorporated into BECMA and TGDM IPN. Copyright (C) 2015 John Wiley & Sons, Ltd.

Abstract  Many problems have emerged in road construction due to insufficient adhesion and elasticity of asphalt layers as road surface. Adding polymer to bitumen can improve and modify asphalt properties. Oligo ester can be used as an additive to improve bitumen properties. Through reaction of recycled polyethylene terephthalate with dipropyleneglycol, oligo ester was produced during the glycolysis process. In this research, oligo ester was fabricated through glycolysis reaction. Then it was added to the bitumen grade 80-100 in 2 and 5wt%. The end product was evaluated by standard test methods for ductility, softening point, penetration, and thermal behavior was measured by Thermal Gravimetric, Differential Thermal Gravimetric, and Differential Thermal Analysis. The results revealed that the addition of the above polymers to bitumen reduced penetration property and increased softening point and ductility. Also, thermal behavior of bitumen was modified.

Abstract  Sodium alginate (SA) films were prepared by casting from methanol (MeOH) solutions and their tensile properties, like tensile strength (TS) and elongation at break (Eb %), were monitored. The resulting films of SA were photocured with vinyltriethoxysilane [H2C=CH-Si-(OC2H5)(3)] in order to improve the tensile properties. Several acrylic monomers of different functionalities as additives (2%), like ethyl acrylate (EA), 2-hydroxyethyl acrylate (2-HEA), and tripropylene glycol diacrylate (TPGDA), were incorporated with silane with the aid of UV radiation. Further analyses of the prepared films were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and a TS test. FTIR studies indicate that there are intermolecular hydrogen bonding interactions, i.e., -OH center dot center dot center dot center dot center dot O=C in silane/SA blends. This blend films also exhibited the higher thermal stability and improved the tensile properties of the films. Degradation of SA by UV spectrometry induces time-dependent degradation.

Abstract  Curing behaviour of unsaturated polyester (UPE) resins based on recycled poly(ethylene terephthalate) (RPET) was investigated by measuring exotherms during cure employing differential scanning calorimetry. The UPE resins were prepared by glycolysis of RPET and polycondensation of the glycolysis product with maleic anhydride. In the preparation of the UPE resins, RPET content and glycol type were varied. The curing behaviour of the UPE resins based on RPET was similar to that of conventional UPE resins. The rate of cure increased with increasing RPET content of the UPE resin based on propylene glycol (PG) and RPET. It decreased with increasing RPET content of the UPE resin based on dipropylene glycol (DPG) and RPET. The final degree of isothermal cure increased with increasing RPET content, or changing the glycol type from PG to DPG, in the UPE resins. The curing behaviour was interpreted from the viewpoints of change in double bond concentration, inherent reactivity, and styrene/fumarate ratio of the UPE resins.

Abstract  A variety of polymeric films were developed to improve the properties of hardboard surface. Polyester acrylate (M-6100) oligomer, and three different types of monomers and photoinitiator (Irgacure-651) were employed to prepare the polymeric films. The monomers are 2-ethyl hexyl acrylate (EHA), tripropylene glycol diacrylate (TPGDA) and trimethylol propane triacrylate (IMPTA). Pendulum hardness and gel content of films prepared by various formulations of oligomer and monomers under UV radiation were characterized against the number of passes for selection of suitable films. The monomer, TMPTA was selected to apply for surface coating with oligomer on hardboard for their optimum properties. Monomers, various properties, such as, pendulum hardness, gloss, abrasion and adhesion tests, indent length and depth, adhesion chipped off area, etc. of coated hardboard surface were determined. Filler, CaCO3, was incorporated into the solution. The hardness increases with increasing the amount of CaCO3 and then decreases. The effect of an additive, such as MEK was also investigated.

Abstract  Part I of this article presents results of an experimental study on gas-phase nucleation for three model solutes and their solvent, propylene glycol (PG), with variables being solute concentration and the nature of the solute substance. A single manifestation of an aerosol generator, which forms condensation aerosols by cooling of hot vapor issuing from an electrically heated, pumped capillary, is described and used for all experiments. The effects of solute concentration and solute type were studied for deoxycorticosterone (DOC), benzil (BZ), and phenyl salicylate (PhS). Suppression of homogeneous nucleation and occurrence of heterogeneous condensation of the solvent was observed at different solute concentrations for BZ, PhS, and DOC. The nature and concentration of the solute dissolved in the solvent was shown to determine the final particle size distribution of the condensed aerosol. In the case of the least volatile solute, DOC, solute aerosol and total aerosol size distributions were identical at low solute concentrations. A transitional concentration region then existed in which a bimodal solute aerosol was formed, followed at high concentrations by increasing separation of the solvent-dominated aerosol size distribution and that of the solute.

In Part II of this article, the effect of DOC dissolution in different solvents was studied at fixed solute concentration. The effects of six glycol solvents-i.e., PG, ethylene glycol (EG), dipropylene glycol (DPG), diethylene glycol (DEG), triethylene glycol (TEG), and tetraethylene glycol (TetEG)-and three nonglycol solvents-i.e., dimethyl sulfoxide (DMSO), formamide (FORM), and oleyl alcohol (OA)-were studied, as these affected the resultant aerosol sizes. Suppression of total aerosol mass median aerodynamic diameter (MMAD) was observed on dissolution of 0.5% w/w DOC in each solvent, although suppression occurred to different extents. It was shown that the boiling point or volatility of the solvent used to dissolve the less volatile DOC had an effect on the final particle size distribution of the condensed aerosol and whether the aerodynamic size distributions for the solute and the total aerosol were the same or different.

Abstract  The maternal and developmental toxicities of dipropylene-glycol-monomethyl-ether (20324327) (DPGME) were evaluated in rabbits and rats. The DPGME used was a commercial mixture of four isomers with a maximum theoretical yield of 61.8% of the beta isomer of propylene-glycol-methyl-ether (107982) (beta-PGME). New-Zealand-White-rabbits and Fischer-344-rats were used in the study. Groups of 16 inseminated rabbits or 32 to 37 bred rats were exposed via inhalation for 6 hours a day to 0, 50, 150, or 300 parts per million (ppm) DPGME on gestation days seven through 19 for rabbits and six through 15 for rats. No treatment related effects on the reproductive and fetal parameters recorded, or on the incidence of malformations or variations in fetuses were observed at any exposure level in either species. The exposure levels were not maternally toxic, embryo/fetotoxic or teratogenic. The authors conclude that since no developmental effects were observed in either rabbits or rats following exposure to 300ppm DPGME, the highest concentration of DPGME practicably attainable at room temperature and pressure, it is unlikely that sufficient atmospheric concentrations of DPGME could be generated to result in the formation of sufficient amounts of metabolite beta-PGME to represent a developmental hazard following DPGME exposure.

Abstract  Shrinkage behavior of the structural foam lightweight concrete with density of 1600 kg/m(3) was investigated. Owing to high drying shrinkage of the lightweight concrete, glycol compounds were used in the concrete mixture to study their effect on shrinkage behavior. Propylene glycol (PG), triethylene glycol (TEG) and dipropylene glycol tert-butyl ether (DPTE) were selected for testing of drying shrinkage of the lightweight concrete. Partial replacement of cement and sand with fly ash was also used to reduce the shrinkage. Results indicated that PG, TEG and DPTE were effective in reducing the shrinkage of lightweight concrete through reduction of surface tension of water. However, DPTE significantly reduced the surface tension and caused the foam instability and early stiffening of mixture. The partial replacement of cement and sand with fly ash could also reduce the shrinkage of the lightweight concrete. In this case, the compressive strength was also enhanced owing to the additional pozzolanic reaction. (C) 2010 Elsevier Ltd. All rights reserved.