Enthalpies of fusion and solid-to-solid transition,entropies of fusion for urea and twelve alkylureas

Enthalpies and temperatures of fusion have been measured by differential scanning calorimetry for urea and a number of its mono- and di-alkyl derivatives. Enthalpies obtained are: urea, 14.79 kj mol⁻¹; monomethylurea, 15.75 kJ mol⁻¹ ; monoethylurea, 13.94 kJ mol⁻¹ ; monopropylurea, 14.63 kJ mol⁻¹ ; monoisopropylurea, 17.40 kJ mol⁻¹ ; monobutylurea, 14.55 kJ mol⁻¹ ; monotertbutylurea, 33.13 kJ mol⁻¹ ; dimethyl-1,1 urea, 29.61 kJ mol⁻¹ ; dimethyl-1,3 urea, 13.62 kJ mol⁻¹; diethyl-1,1 urea, 16/78 kJ mol⁻¹ ; diethyl-1,3 urea, 12.46 kJ mol⁻¹ ; dibutyl-1,3 urea, 14.87 kJ mol⁻¹; trimethyl-1,1,3 urea, 14.30 kJ mol⁻¹. Entropies of fusion have been derived from the experimental results.By temperature scanning starting from r.t. some solid-to-solid transitions for four alkylureas have also been detected, all hitherto unreported. Temperatures and enthalpies of transition are: for monoisopropylurea, 375.5 K and 2.31 kJ mol ⁻¹ ; for monobutylurea (two transitions), 313.1 K and 7.02 kJ mol⁻¹ , 344.9 K and 0.88 kJ mol⁻¹ ; for diethyl-1,3 urea, 339.4 K and 1.87 kJ mol⁻¹ ; for dibutyl-1,3 urea, 311.5 K and 11.10 kJ mol⁻¹.     

Enthalpic analysis of the CaTiSiO5 system

The relative enthalpy of titanite and enthalpy of CaTiSiO₅ melt have been measured using drop calorimetry between 823 K and 1843 K. Enthalpies of solution of titanite and CaTiSiO₅ glass have been measured by the use of hydrofluoric acid solution calorimetry at 298 K. Enthalpy of vitrification at 298 K, δ_vitr H(298 K) = (80.7 ± 3.4) kJ mol⁻¹, and enthalpy of fusion at the temperature of fusion 1656 K, δ_fus H(1656 K) = (139 ± 3) kJ mol⁻¹, of titanite have been determined from experimental data. The obtained enthalpy of fusion is considerably higher than up to the present published values of this quantity.     

DSC determination of the sublimation enthalpy of bis(2,4-pentanedionato)oxovanadium(IV) and tetrakis(2,4-pentanedionato)zirconium(IV)

The sublimation enthalpies of bis(2,4-pentanedionato)oxovanadium(IV) and tetrakis(2,4-pentanedionato)zirconium(IV) have been determined by differential scanning calorimetry as 140.7 ± 4.0 and 132.0 ± 6.8 kJ mol⁻¹, respectively. The fusion enthalpy of the latter complex has also been determined as 33.68 ± 2.5 kJ mol⁻¹. A summary of “selected” sublimation enthalpy data for first-row transition metal acetylacetonate complexes is included.     

Protonation of CO2, COS,CS2: Proton affinities and the structures of the protonated species

The geometric structures of a number of isomers of the ions formed by protonation of CO₂, COS and CS₂, and of the parent molecules themselves, have been fully optimized using ab initio quantum chemical methods. Stable minima have been found both for molecules protonated at the terminal atom and at the central carbon atom; ions of the latter type show strong near-degeneracy effects which have been ignored in previous calculations. Proton affinities of CO₂, COS and CS₂ have been calculated: for CO₂ the theoretical result (565 kJ mol⁻¹) is in excellent agreement with experiment (540 kJ mol⁻¹), given that the experimental proton affinity includes a contribution from zero-point vibration of ≈ −27 kJ mol⁻¹. For COS, for which no experimental value is available, the calculations give almost identical results for both O and S protonated species (619 and 636 kJ mol⁻¹, respectively). It may not therefore be possible to distinguish these two isomers experimentally. The theoretical result for CS₂ (678 kJ mol⁻) suggests that the current experimental value of the proton affinity (699 kJ mol⁻¹) is too high, since this value includes a zero-point vibration contribution of some −19 kJ mol⁻¹).     

High-level computational study on the thermochemistry of saturated and unsaturated three- and four-membered nitrogen and phosphorus rings

The heats of formation and strain energies for saturated and unsaturated three- and four-membered nitrogen and phosphorus rings have been calculated using G2 theory. G2 heats of formation (ΔH_f298) of triaziridine [(NH)₃], triazirine (N₃H), tetrazetidine [(NH)₄], and tetrazetine (N₄H₂) are 405.0, 453.7, 522.5, and 514.1 kJ mol⁻¹, respectively. Tetrazetidine is unstable (121.5 kJ mol⁻¹ at 298 K) with respect to its dissociation into two trans-diazene (N₂H₂) molecules. The dissociation of tetrazetine into molecular nitrogen and trans-diazene is highly exothermic (ΔH₂₉₈ = −308.3 kJ mol⁻¹ calculated using G2 theory). G2 heats of formation (ΔH_f298) of cyclotriphosphane [(PH)₃], cyclotriphosphene (P₃H), cyclotetraphosphane [(PH)₄], and cyclotetraphosphene (P₄H₂) are 80.7, 167.2, 102.7, and 170.7 kJ mol⁻¹, respectively. Cyclotetraphosphane and cyclotetraphosphene are stabilized by 145.8 and 101.2 kJ mol⁻¹ relative to their dissociations into two diphosphene molecules or into diphosphene (HP(DOUBLE BOND)PH) and diphosphorus (P₂), respectively. The strain energies of triaziridine [(NH)₃], triazirine (N₃H), tetrazetidine [(NH)₄], and tetrazetine (N₄H₂) were calculated to be 115.0, 198.3, 135.8, and 162.0 kJ mol⁻¹, respectively (at 298 K). While the strain energies of the nitrogen three-membered rings in triaziridine and triazirine are smaller than the strain energies of cyclopropane (117.4 kJ mol⁻¹) and cyclopropene (232.2 kJ mol⁻¹), the strain energies of the nitrogen four-membered rings in tetrazetidine and tetrazetine are larger than those of cyclobutane (110.2 kJ mol⁻¹) and cyclobutene (132.0 kJ mol⁻¹). In contrast to higher strain in cyclopropane as compared with cyclobutane, triaziridine is less strained than tetrazetidine. The strain energies of cyclotriphosphane [(PH)₃, 21.8 kJ mol⁻¹], cyclotriphosphene (P₃H, 34.6 kJ mol⁻¹), cyclotetraphosphane [(PH)₄, 24.1 kJ mol⁻¹], and cyclotetraphosphene (P₄H₂, 18.5 kJ mol⁻¹), calculated at the G2 level are considerably smaller than those of their carbon and nitrogen analog. Cyclotetraphosphene containing the P(DOUBLE BOND)P double bond is less strained than cyclotetraphosphane, in sharp contrast to the ratio between the strain energies for the analogous unsaturated and saturated carbon and nitrogen rings. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 62 : 373–384, 1997     

Determination of propagation rate coefficients for an α‐substituted acrylic ester: Pulsed laser polymerization of dimethyl itaconate

Pulsed laser polymerization experiments have been performed on the bulk polymerization of dimethyl itaconate over the temperature range 20–50 °C. The activation energy and frequency factor were calculated as 24.9 kJ/mol⁻¹ and 2.15 × 10⁵ L/mol⁻¹s⁻¹, respectively. The activation energy is comparable with the methacrylate series of monomers. The frequency factor is relatively small and reflects steric hindrance in the transition state caused by the bulky 1,1, disubstitution in the monomer (and consequently the radical). The Mark–Houwink–Kuhn–Sakurada constants were also determined for poly(dimethyl itaconate) in tetrahydrofuran, these are reported as 46 × 10⁻⁵ dL/g (K) and 0.51 (α). The influence of penultimate units (γ‐substituents) on homopropagation reactions is discussed particularly for polymerizations leading to significant 1,3 interactions in the resultant polymer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2192–2200, 2000     

Two Three‐Dimensional Metal‐Organic Frameworks Constructed from Alkaline Earth Metal Cations (Sr and Ba) and 5‐Nitroisophthalicacid – Synthesis,Charaterization, and Thermochemistry

Two MOFs of [Sr^II(5‐NO₂‐BDC)(H₂O)₆] ( 1 ) and [Ba^II(5‐NO₂‐BDC)(H₂O)₆] ( 2 ) have been synthesized in water using alkaline earth metal salts and the rigid organic ligand 5‐NO₂‐H₂BDC. The compounds were characterized by elemental analysis, infrared spectrum, thermal analysis, and X‐ray crystallography. Crystal structure analyses have shown that the two complexes are isostructural as evidenced by IR spectra and TG‐DTA. Both compounds present three‐dimensional frameworks built up from infinite chains of edge‐sharing twelve‐membered rings through O–H···O hydrogen bonds. The specific heat capacities of the title complexes have been determined by an improved RD496‐III microcalorimeter with the values of (109.29 ± 0.693) J mol⁻¹ K⁻¹ and (81.162 ± 0.858) J mol⁻¹ K⁻¹ at 298.15 K, and the molar enthalpy changes of the formation reactions of complexes at 298.15 K were calculated as (4.897 ± 0.008) kJ mol⁻¹ and (2.617 ± 0.009) kJ mol⁻¹, respectively.     

Heat capacity of poly(trimethylene terephthalate)

The heat capacity of poly(trimethylene terephthalate) (PTT) has been measured using adiabatic calorimetry, standard differential scanning calorimetry (DSC), and temperature-modulated differential scanning calorimetry (TMDSC). The heat capacities of the solid and liquid states of semicrystalline PTT are reported from 5 to 570 K. The semicrystalline PTT has a glass transition temperature of 331 K. Between 340 and 480 K, PTT can show exothermic ordering depending on the prior degree of crystallization. The melting endotherm of semicrystalline samples occurs between 480 and 505 K, with a typical onset temperature of 489 K (216°C). The heat of fusion of the semicrystalline samples is about 15 kJ mol⁻¹. For 100% crystalline PTT the heat of fusion is estimated to be 30 ± 2 kJ mol⁻¹. The heat capacity of solid PTT is linked to an approximate group vibrational spectrum and the Tarasov equation is used to estimate the heat capacity contribution due to skeletal vibrations (θ₁ = 550.5 K and θ₂ = θ₃ = 51 K, N_skeletal = 19). The calculated and experimental heat capacities agree to better than ±3% between 5 and 300 K. The experimental heat capacities of liquid PTT can be expressed by: $ C^L_p(exp) $ = 211.6 + 0.434 T J K⁻¹ mol⁻¹ and compare to ±0.5% with estimates from the ATHAS data bank using contributions of other polymers with the same constituent groups. The glass transition temperature of the completely amorphous polymer is estimated to be 310–315 K with a ΔC_p of about 94 J K⁻¹ mol⁻¹. Knowing C_p of the solid, liquid, and the transition parameters, the thermodynamic functions enthalpy, entropy, and Gibbs function were obtained. With these data one can compute for semicrystalline samples crystallinity changes with temperature, mobile amorphous fractions, and resolve the question of rigid-amorphous fractions.© 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2499–2511, 1998     

Excess enthalpies,and vapor-liquid equilibrium and surface properties of the highly non-ideal associated mixtures formed by an alcohol and propanal

Excess enthalpies, vapor-liquid equilibrium data and surface tensions of the highly non-ideal associated mixtures formed by methanol or ethanol and propanal have been measured in the temperature range of 288.15–318.15 K. These mixtures show negative deviations from ideality, including a negative azeotrope for the methanolpropanal system in the methanol-rich region. The values for the excess enthalpies are very exothermic and become less negative as temperature increases. Methanolpropanal mixtures exhibit minima of approximately −8.6 and −8.0 kJ mol⁻¹, at a mole fraction close to 0.5 and 298.15 and 318.15 K, respectively. The ethanolpropanal system exhibits minima of approximately −7.2 and −5.0 kJ mol⁻¹ at 298.15 and 318.15 K, respectively.The surface tension has been measured at 298.15 K. Values for the relative surface adsorption calculated from the surface tension and the chemical potentials indicate that the surface is significantly enriched in propanal for mixtures rich in methanol. The calculated values for the concentration-concentration correlation function are lower than those corresponding to an ideal mixture and exhibit a minimum in the middle of the concentration range. A complex composition dependence of the concentration profiles can be inferred.The Lattice-Fluid Associated Solution, the UNIQUAC Associated Solution and the Extended Real Associated Solution models have been used to describe the bulk properties of the alcoholpropanal mixtures.     

Vibrational circular dichroism in hydrogen bond systems: Part II. Vibrational circular dichroism of the OH stretching vibration in 2,2-dimethyl-1,3-dioxolane-4-methanol

Vibrational circular dichroism (VCD) of the OH stretching band in 2,2-dimethyl-1,3- dioxolane-4-methanol has been studied. The OH stretching vibration for the intramolecularly hydrogen-bonded species in the (R)-enantiomer gives rise to a positive VCD band but no VCD band for the hydrogen-bond free species. It is shown that the G⁻G⁺ conformation in the intramolecular hydrogen bond system

gives a positive VCD band for the OH stretching vibration. The thermodynamic parameters in equilibrium between the free and intramolecularly hydrogen-bonded species have been determined as ΔH =−7.8 kJ mol⁻¹ and ΔS = −18 kJ K⁻¹ mol⁻¹.     

The structure and thermochemistry of 3:4,5:6-dibenzo-2-hydroxymethylene-cyclohepta-3,5-dienenone (1) and some related compounds

Condensed and gas phase enthalpies of formation of 3:4,5:6-dibenzo-2-hydroxymethylene-cyclohepta-3,5-dienenone (1, (−199.1 ± 16.4), (−70.5 ± 20.5) kJ mol⁻¹, respectively) and 3,4,6,7-dibenzobicyclo[3.2.1]nona-3,6-dien-2-one (2, (−79.7 ± 22.9), (20.1 ± 23.1) kJ mol⁻¹) are reported. Sublimation enthalpies at T=298.15 K for these compounds were evaluated by combining the fusion enthalpies at T = 298.15 K (1, (12.5 ± 1.8); 2, (5.3 ± 1.7) kJ mol⁻¹) adjusted from DSC measurements at the melting temperature (1, (T _fus, 357.7 K, 16.9 ± 1.3 kJ mol⁻¹)); 2, (T _fus, 383.3 K, 10.9 ± 0.1) kJ mol⁻¹) with the vaporization enthalpies at T = 298.15 K (1, (116.1 ± 12.1); 2, (94.5 ± 2.2) kJ mol⁻¹) measured by correlation-gas chromatography. The vaporization enthalpies of benzoin ((98.5 ± 12.5) kJ mol⁻¹) and 7-heptadecanone ((94.5 ± 1.8) kJ mol⁻¹) at T = 298.15 K and the fusion enthalpy of phenyl salicylate (T _fus, 312.7 K, 18.4 ± 0.5) kJ mol⁻¹) were also determined for the correlations. The crystal structure of 1 was determined by X-ray crystallography. Compound 1 exists entirely in the enol form and resembles the crystal structure found for benzoylacetone.     

Phase transition in hydrazinium hydrogen oxalate. A calorimetric study of the short hydrogen bond system

The heat capacity of hydrazinium hydrogen oxalate crystal has been measured between 14 and 300 K. A first-order phase transition was found at 217.6 K. Total transition enthalpy and entropy are 1.09 kJ mol⁻¹ and 4.18 J K⁻¹ mol⁻¹, respectively. The high temperature phase supercooled to 165−170 K. The heat capacity of the supercooled high temperature phase was significantly larger than that of the low temperature phase. By fitting a Schottky heat capacity function to the heat capacity difference, a Schottky energy level was found at (135 ± 4) cm⁻¹ above the ground state and related to the tunneling splitting of the energy levels of the short acidic hydrogen bond. A thermodynamic model of the first-order transition is proposed in which the Schottky anomaly plays the main role. Far-infrared spectra of hydrazinium hydrogen oxalate are reported for the frequency range 400–30 cm⁻¹ at temperatures of 295 and 90 K.     

The kinetics and mechanisms of gas phase elimination of primary,secondary, and tertiary 2‐hydroxyalkylbenzenes

2‐Phenylethanol, racemic 1‐phenyl‐2‐propanol, and 2‐methyl‐1‐phenyl‐2‐propanol have been pyrolyzed in a static system over the temperature range 449.3–490.6°C and pressure range 65–198 torr. The decomposition reactions of these alcohols in seasoned vessels are homogeneous, unimolecular, and follow a first‐order rate law. The Arrhenius equations for the overall decomposition and partial rates of products formation were found as follows: for 2‐phenylethanol, overall rate log k₁(s⁻¹)=12.43−228.1 kJ mol⁻¹ (2.303 RT)⁻¹, toluene formation log k₁(s⁻¹)=12.97−249.2 kJ mol⁻¹ (2.303 RT)⁻¹, styrene formation log k₁(s⁻¹)=12.40−229.2 kJ mol⁻¹(2.303 RT)⁻¹, ethylbenzene formation log k₁(s⁻¹)=12.96−253.2 kJ mol⁻¹(2.303 RT)⁻¹; for 1‐phenyl‐2‐propanol, overall rate log k₁(s⁻¹)=13.03−233.5 kJ mol⁻¹(2.303 RT)⁻¹, toluene formation log k₁(s⁻¹)=13.04−240.1 kJ mol⁻¹(2.303 RT)⁻¹, unsaturated hydrocarbons+indene formation log k₁(s⁻¹)=12.19−224.3 kJ mol⁻¹(2.303 RT)⁻¹; for 2‐methyl‐1‐phenyl‐2‐propanol, overall rate log k₁(s⁻¹)=12.68−222.1 kJ mol⁻¹(2.303 RT)⁻¹, toluene formation log k₁(s⁻¹)=12.65−222.9 kJ mol⁻¹(2.303 RT)⁻¹, phenylpropenes formation log k₁(s⁻¹)=12.27−226.2 kJ mol⁻¹(2.303 RT)⁻¹. The overall decomposition rates of the 2‐hydroxyalkylbenzenes show a small but significant increase from primary to tertiary alcohol reactant. Two competitive eliminations are shown by each of the substrates: the dehydration process tends to decrease in relative importance from the primary to the tertiary alcohol substrate, while toluene formation increases. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 401–407, 1999     

The isomolecular exchange reaction Ga2S(g) + In2S(g) = 2 InGaS(g)

Equilibria involving the molecules Ga₂S(g), In₂S(g), and InGaS(g), by the reaction Ga₂S(g) + In₂S(g) = 12InGaS(g) were investigated between 1060–1350 K by the Knudsen-effusion, mass-spectrometric method. The reaction enthalpy at 298 K was calculated to be 0±1 kJ mol⁻¹. The enthalpy of formation of InGaS at 298 K and the enthalpy of atomization of InGaS at 298 K were calculated to be 80±18 kJ mol⁻¹ and 710±18 kJ mol⁻¹, respectively. The equilibrium constant and the enthalpy of reaction indicated that the three gaseous molecules have a bent triatomic structure in which S is a center atom and no bond between metals.     

Theoretical and experimental studies of the diketene system: Product branching decomposition rate constants and energetics of isomers

The kinetics and mechanism for the thermal decomposition of diketene have been studied in the temperature range 510–603 K using highly diluted mixtures with Ar as a diluent. The concentrations of diketene, ketene, and CO₂ were measured by FTIR spectrometry using calibrated standard mixtures. Two reaction channels were identified. The rate constants for the formation of ketene (k₁) and CO₂ (k₂) have been determined and compared with the values predicted by the Rice–Ramsperger–Kassel–Marcus (RRKM) theory for the branching reaction. The first-order rate constants, k₁ (s⁻¹) = 10^{15.74 ± 0.72} exp(−49.29 (kcal mol⁻¹) (±1.84)/RT) and k₂ (s⁻¹) = 10^{14.65 ± 0.87} exp(−49.01 (kcal mol⁻¹) (±2.22)/RT); the bulk of experimental data agree well with predicted results. The heats of formation of ketene, diketene, cyclobuta-1,3-dione, and cyclobuta-1,2-dione at 298 K computed from the G2M scheme are −11.1, −45.3, −43.6, and −40.3 kcal mol⁻¹, respectively. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 580–590, 2007     

Solvation parameters for amino acids

Atomic radii have been derived for the common amino acid side chains using a solvent interaction potential (SIP) based on quantum mechanically derived charges. Solvation energies calculated using these parameters are compared with those obtained using other sets of radii and charges, and from alternative methods. The differences from the experimental solvation energies for the nonionizable residues are all less than 10 kJ mol⁻¹. The largest error in the solvation energy occurs for acetic acid (−16.0 kJ mol⁻¹). For the charged side chain systems the difference from experiment are all less than 10 kJ mol⁻¹. SIP parameters for the aminoacetaldehyde derivatives of the common amino acids are presented. These are used in the calculation of the relative binding energies of six benzamidine inhibitors with trypsin. ©1999 John Wiley & Sons, Inc. J Comput Chem 20: 428–442, 1999     

Determination of the enthalpy of fusion of K<Subscript>3</Subscript>TaO<Subscript>2</Subscript>F<Subscript>4</Subscript> and KTaF<Subscript>6</Subscript>

Areas of fusion and crystallization peaks of K₃TaO₂F₄ and KTaF₆ were measured using the DSC mode of a high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities, considering the temperature dependence of the calorimeter sensitivity, values of the fusion enthalpy of K₃TaO₂F₄ at the fusion temperature of 1181 K of (43 ± 4) kJ mol⁻¹ and of KTaF₆ at the fusion temperature of 760 K of (8 ± 1) kJ mol⁻¹ were determined.     

Studies on the oxidation mechanism of H2S based on direct examination of the key reactions

By conducting an excimer laser photolysis (193 and 248 nm) behind shock waves, three elementary reactions important in the oxidation of H₂S have been examined, where, H, O, and S atoms have been monitored by the atomic resonance absorption spectrometry. For HS + O₂ → products (1), the rate constants evaluated by numerical simulations are summarized as: k₁ = 3.1 × 10⁻¹¹exp|-75 kJ mol⁻¹/RT| cm³molecule⁻¹s⁻¹ (T = 1400-1850 K) with an uncertainty factor of about 2. Direct measurements of the rate constants for S + O2 → SO + O (2), and SO + O₂ → SO₂ + O (3) yield k₂ = (2.5 ± 0.6) × 10⁻¹¹ exp|-(15.3 ± 2.5) kJ mol⁻¹/RT| cm³molecule⁻¹s⁻¹ (T = 980-1610 K) and, k₃ = (1.7 ± 0.9) × 10⁻¹² exp|-(34 ± 11) kJ mol⁻¹/RT| cm³molecule⁻¹s⁻¹ (T = 1130-1640 K), respectively. By summarizing these data together with the recent experimental results on the H(SINGLE BOND)S(SINGLE BOND)O reaction systems, a new kinetic model for the H₂S oxidation process is constructed. It is found that this simple reaction scheme is consistent with the experimental result on the induction time of SO₂ formation obtained by Bradley and Dobson. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 57–66, 1997.     

Gold Nanoparticles Formation via Au(III) Complex Ions Reduction with l‐Ascorbic Acid

In this paper, the kinetics and mechanism of gold nanoparticles formation during the redox reaction between [AuCl₄]− complex and l ‐ascorbic acid under different conditions were described. It was also shown that reagent concentration, chloride ions, and pH influence kinetics of nucleation and growth. To establish rate constants of these stages, the model of Finke and Watzky was applied. From Arrhenius and Eyring dependencies, the values of activation energy (22.5 kJ mol⁻¹ for the nucleation step and 30.3 kJ mol⁻¹ for the growth step), entropy (about −228 J K⁻¹ mol⁻¹ for the nucleation step and −128 J K⁻¹ mol⁻¹ for the growth step), and enthalpy (19.8 kJ mol⁻¹ for nucleation and 27.8 kJ mol⁻¹ for particles growth) were determined. It was also shown that the disproporationation reaction had influence on the rate of nanoparticles formation and may have impact on final particles morphology.     

Volume dependence of thermal conductivity and bulk modulus for poly(propylene glycol)

The thermal conductivity λ and heat capacity per unit volume of poly(propylene glycol) PPG (0.4 and 4.0 kg·mol⁻¹ in number-average molecular weight) have been measured in the temperature range 150–295 K at pressures up to 2 GPa using the transient hot-wire method. At 295 K and atmospheric pressure, λ = 0.147 W m⁻¹K⁻¹ for PPG (0.4 kg·mol⁻¹) and λ = 0.151 W m⁻¹K⁻¹ for PPG (4.0 kg·mol⁻¹). The temperature dependence of λ is less than 4 × 10⁻⁴ W m⁻¹K⁻² for both molecular weights. The bulk modulus has been measured in the temperature range 215–295 K up to 1.1 GPa. At atmospheric pressure, the room temperature bulk moduli are 1.97 GPa for PPG (0.4 kg·mol⁻¹) and 1.75 GPa for PPG (4.0 kg·mol⁻¹). These data were used to calculate the volume dependence of $ \lambda ,g\, = - \left( {\frac{{\partial \lambda /\lambda }}{{\partial V/V}}} \right)_T $. At room temperature and atmospheric pressure (liquid phase) we find g = 2.79 for PPG (0.4 kg·mol⁻¹) and g = 2.15 for PPG (4.0 kg·mol⁻¹). The volume dependence of g, (∂g/∂ log V)_T varies between −19 to −10 for both molecular weights. Under isochoric conditions, g is nearly independent of temperature. The difference in g between the glassy state and liquid phase is small and just outside the inaccuracy of g of about 8%. The theoretical model for λ by Horrocks and McLaughlin yields an overestimate of g by up to 120%. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36 : 345–355, 1998