Study of TATP: Influence of Reaction Conditions on Product Composition

The influence of reaction conditions (temperature, catalyst type, catalyst concentration – represented as molar ratio catalyst/acetone n_c/n_a) on the composition of the product formed from the reaction of acetone and hydrogen peroxide (30%) under acid catalysis was studied. 3,3,6,6,9,9‐Hexamethyl‐1,2,4,5,7,8‐hexoxonane (TATP) was found to be the major product when the content of the catalyst in the reaction mixture is low (n_c/n_a ≤ 0.5). A single side product (peak 10.2) in an amount ranging from 1.5 to 8% of the total peak area was present in all the prepared samples. Three other side products were found when catalyzing by hydrochloric and nitric acids. Temperature and catalyst type did not have a significant influence on the composition of the product at low catalyst concentration. Increasing the catalyst concentration led to the formation of 3,3,6,6‐tetramethyl‐1,2,4,5‐tetroxane (DADP) either as a co‐product of TATP or as an exclusive product depending on the concentration of the catalyst.     

Factors Influencing Triacetone Triperoxide (TATP) and Diacetone Diperoxide (DADP) Formation: Part I

Conditions, which result in the formation of triacetone triperoxide (TATP) or diacetone diperoxide (DADP) from acetone and hydrogen peroxide (HP, were studied for the purposes of inhibiting the reaction. Reaction of HP with acetone precipitates either DADP or TATP, but the overall yield and amount of each was found to depend on (1) reaction temperature, (2) the molar ratio of acid to HP/acetone, (3) initial concentrations of reactants, and (4) length of reaction. Controlling molar ratios and concentrations of starting materials was complicated because both sulfuric acid and hydrogen peroxide were aqueous solutions. Temperature exercised great control over the reaction outcome. Holding all molar concentrations constant and raising the temperature from 5 to 25 °C showed an increase of DADP over TATP formation and a decrease in overall yield. At 25 °C a good yield of TATP was obtained if the HP to acetone ratio was kept between 0.5 : 1 and 2 : 1. At constant temperature and HP‐to‐acetone held at one‐to‐one ratio, acid‐to‐HP molar ratios between 0.10 : 1 and 1.2 : 1 produced good yield of TATP. Plotting the molality of HP vs. that of sulfuric acid revealed regions, in which relatively pure DADP or pure TATP could be obtained. In addition to varying reaction conditions, adulterants placed into acetone were tested to inhibit the formation of TATP. Because there is much speculation of the relative stability, sensitivity, including solvent wetting of crystals, and performance of DADP and TATP, standard tests (i.e. DSC, drop weight impact, and SSED) were performed.     

Study of TATP: Spontaneous Transformation of TATP to DADP

TATP, prepared in the presence of catalysts methanesulfonic, perchloric, or sulfuric acid, has been found to undergo transformation to DADP. However, no transformation occurs if TATP is purified or prepared involving catalysts such as hydrochloric acid, tin(IV) chloride, and nitric acid. The transformation has been monitored by the methods of DTA and HPLC.     

Study of TATP: Formation of New Chloroderivates of Triacetone Triperoxide

The existence of two new types of chloroderivates of cyclic acetone peroxides – 3‐(chloromethyl)‐3,6,6,9,9‐pentamethyl‐1,2,4,5,7,8‐hexoxonane and 3,6‐bis(chloromethyl)‐3,6,9,9‐tetramethyl‐1,2,4,5,7,8‐hexoxonane was proved by HPLC/MS/MS and NMR in the reaction products when acetone and hydrogen peroxide are mixed in the presence of excess hydrochloric acid (molar ratio hydrochloric acid to acetone n_c/n_a=2.5). The details of analysis, and the conditions under which these asymmetric chloroderivates of cyclic peroxides form, are described.     

Factors Influencing Destruction of Triacetone Triperoxide (TATP)

Acid catalyzes the formation of triacetone triperoxide (TATP) from acetone and hydrogen peroxide, but acid also destroys TATP, and, under certain conditions, converts TATP to diacetone diperoxide (DADP). Addition of strong acids to TATP can cause an explosive reaction, while reaction with dilute acid reduces the decomposition rate so drastically that gentle destruction of TATP is impractical. However, combined use of dilute acid with slightly solvated TATP made gentle destruction of TATP feasible. Variables including acid type, concentration, solvent and ratios thereof have been explored, along with kinetics, in an attempt to provide a field‐safe technique for gently destroying this homemade primary explosive. The preferred method is moistening TATP with an alcoholic solution (aqueous methanol, ethanol, or iso‐propanol) followed by addition of 36 wt‐% hydrochloric acid. Preliminary experiments have shown the technique to be safe and effective for destruction of hexamethylene triperoxide diamine (HMTD), as well.     

Taming the Beast: Measurement of the Enthalpies of Combustion and Formation of Triacetone Triperoxide (TATP) and Diacetone Diperoxide (DADP) by Oxygen Bomb Calorimetry

Low‐melting paraffin wax was successfully used as a phlegmatizing agent to perform semi‐micro oxygen bomb calorimetry of spectroscopically pure samples of the sensitive explosive peroxides TATP and DADP. The energies of combustion (Δ_cU) were measured and the standard enthalpies of formation (Δ_fH°) were derived using the CODATA values for the standard enthalpies of formation of the combustion products. Whilst the measured Δ_fH° of DADP (Δ_fH°=−598.5 ± 39.7 kJ mol⁻¹) could not be compared to any existing literature value, the measured Δ_fH° value of TATP (Δ_fH°=+151.4 ± 32.7 kJ mol⁻¹) did not correlate well with the only existing experimental value and confirmed that TATP is an endothermic cyclic peroxide.     

Direct Detection of Triacetone Triperoxide (TATP) in Real Banknotes from ATM Explosion by EASI‐MS

In Brazil, automated teller machine (ATM) has become a major target of theft incursions toward explosion. Efficient analysis of explosives residues on suspect banknotes is a serious issue in forensic labs, and guide to the crime solution. Easy ambient sonic‐spray ionization mass spectrometry (EASI‐MS) is shown to be a simple and selective screening tool to identify peroxide explosives on real banknotes collected from ATM explosion. Analyses were carried out directly on the banknotes surfaces without any sample preparation, identifying triacetone triperoxide (TATP) and diacetone diperoxide (DADP). Homemade EASI source was coupled to ultrahigh‐resolution and ultrahigh accuracy FT‐ICR MS and revealed the ion of m /z 245 correspondent to sodiated TATP [C₉H₁₈O₆Na]⁺ and the ion of m /z 171 related to sodiated DADP [C₆H₁₂O₄Na]⁺, ions that is the sodiated DADP and the ions of m /z 173 and 189 related to [C₆H₁₄O₄Na]⁺ and [C₆H₁₄O₄K]⁺, respectively, which are associated to chemical markers of TATP domestic route synthesis. EASI source coupled to a single quadrupole mass spectrometer provides an intelligent and simple way to identify the explosives TATP, DADP and its domestic synthesis markers.     

Factors Influencing Triacetone Triperoxide (TATP) and Diacetone Diperoxide (DADP) Formation: Part 2

A comprehensive mechanistic study regarding acetone peroxides reveals that water has a profound effect on the formation of the solid cyclic peroxides, TATP, and DADP. The identification and rate of occurrence of reaction intermediates as well as compositions of the final products offer explanation for previously reported results indicating that acid type and hydrogen peroxide concentration affect the acid catalyzed reaction between acetone and hydrogen peroxide. A kinetics study of the decomposition of TATP revealed the effects of water and alcohols. They generally retard conversion of TATP to DADP and lead to complete decomposition of TATP by acid. A mechanism is proposed for the production of TATP and DADP.     

Novel Uncatalyzed Synthesis and Characterization of Diacetone Diperoxide

A novel method used to synthesize diacetone diperoxide (DADP) from acetone and hydrogen peroxide without the presence of a catalytic agent is presented. Previously reported syntheses used toluenesulfonic and m‐sulfonic acid as catalyst. DADP was prepared with a purity of 99.99 %. The melting point range (128.5–134.5 °C) is consistent with reported values. The success of the reported procedure depends on controlling the ratio between acetone and hydrogen peroxide as well as the temperature of the reaction mixture. The purified crystalline DADP samples were characterized using NMR, Raman, and IR spectroscopy, differential scanning calorimetry, gas chromatography and open atmosphere chemical ionization mass spectrometry (DART™). The structure was compared to the well‐known cyclic trimer triacetone triperoxide (TATP). The proposed synthetic scheme can be useful for preparing small amounts of the cyclic organic peroxide for characterization and fundamental studies and for formulation of gas chromatography, high performance liquid chromatography, and mass spectrometry standards.     

Knudsen Effusion Measurement of Organic Peroxide Vapor Pressures

The vapor pressures of TATP over the temperature range 269.85–306.95 K and DADP over the temperature range 265.85–294.85 K were determined using a modified Knudsen effusion apparatus. The Clausius‐Clapeyron plot of log₁₀(p(Pa)) with 1/T provided a straight line for each material. This expression for TATP is log₁₀(p(Pa))=−(4497±80)/T(K)+(15.86±0.28) (error limits are 95 % confidence limits) and for DADP it is log₁₀(p(Pa))=−(4417±137)/T(K)+(16.31±0.48). These expressions yield values of the vapor pressure at 298.15 K of 6 Pa for TATP and 17 Pa for DADP, and heats of sublimation of 86.2±1.5 kJ mol⁻¹ for TATP and 84.6±2.6 kJ mol⁻¹ for DADP. Attempts were made to determine the vapor pressure of HMTD but it appears to have a vapor pressure too low for our system to reliably determine. A two month experiment did provide an upper limit estimate for the vapor pressure of HMTD of approximately 0.04 Pa at room temperature. Melting point and melting point range were used as verification of the identity and purity of the TATP and DADP used in these experiments, but this was not possible with HMTD since it detonates prior to melting.     

Determination of the Vapor Density of Triacetone Triperoxide (TATP) Using a Gas Chromatography Headspace Technique

Using a GC headspace measurement technique, the vapor pressure of TATP was determined over the temperature range 12 to 60 °C. As a check on the experimental method, TNT vapor pressure was likewise computed. Values for TNT are in excellent agreement with previous published ones. For TATP the vapor pressure was found to be ~ 7 Pa at ambient conditions. This value translates to a factor of 10⁴ more molecules of TATP in air than TNT at room temperature. The dependence of TATP vapor pressure on temperature can be described by the equation log₁₀P(Pa)=19.791−5708/T(K). Its heat of sublimation has been calculated as 109 kJ/mol.     

Determining the Vapor Pressures of Diacetone Diperoxide (DADP) and Hexamethylene Triperoxide Diamine (HMTD)

The vapor signature of diacetone diperoxide (DADP) and hexamethylene triperoxide diamine (HMTD) were examined by a gas chromatography (GC) headspace technique over the range of 15 to 55 °C. Parallel experiments were conducted to redetermine the vapor pressures of 2,4,6‐trinitrotoluene (TNT) and triacetone triperoxide (TATP). The TNT and TATP vapor pressures were in agreement with the previously reported results. Vapor pressure of DADP was determined to be 17.7 Pa at 25 °C, which is approximately 2.6 times higher than TATP at the same temperature. The Clapeyron equation, relating vapor pressure and temperature, was LnP (Pa)=35.9−9845.1/T (K) for DADP. Heat of sublimation, calculated from the slope of the line for the Clapeyron equation, was 81.9 kJ mole⁻¹. HMTD vapor pressure was not determined due to reduced thermal stability resulting in vapor phase decomposition products.     

Decomposition of a Multi-Peroxidic Compound: Triacetone Triperoxide (TATP)

The thermal decomposition of triacetone triperoxide (TATP) was investigated over the temperature range 151 to 230 °C and found to be first order out to a high degree of conversion. Arrhenius parameters were calculated: activation energy, 151 kJ/mol and pre-exponential factor, 3.75×10¹³ s⁻¹. Under all conditions the principle decomposition products were acetone (about 2 mole per mole TATP in the gas-phase and 2.5–2.6 mole per mole in condensed-phase) and carbon dioxide. Minor products included some ascribed to reactions of methyl radical: ethane, methanol, 2-butanone, ethyl acetate; these increased at high temperature. Methyl acetate and acetic acid were also formed in the decomposition of neat TATP; the former was more evident in the gas-phase decompositions (151 °C and 230 °C) and the latter in the condensed-phase decompositions (151 °C). The decomposition of TATP in condensed-phase or in hydrogen-donating solvents enhanced acetone production, suppressed CO₂ production, and slightly increased the rate constant (a factor of 2–3). All observations were interpreted in terms of decomposition pathways initiated by O O homolysis.     

Gas‐phase Concentration of Triacetone Triperoxide (TATP) and Diacetone Diperoxide (DADP)

The present investigation is about the determination of the gas phase concentration parameters of the notorious explosives triacetone triperoxide (TATP, 1 ) and diacetone diperoxide (DADP, 2 ), which have been frequently used in improvised explosive devices. According to calculations with EXPLO5 the energetic performance of both explosives is similar. The enthalpy of sublimation (298.15 K) ( 1 : 76.7±0.7 kJ mol⁻¹; 2 : 75.0±0.5 kJ mol⁻¹) and vapor pressures (298.15 K) ( 1 : 6.7 Pa, 2 : 26.6 Pa) of both compounds have been studied using the transpiration method in the ambient temperature range of 274–314 K. The results obtained in this work were compared critically with the existing literature values. Data for DADP ( 2 ) mostly shows agreement with literature ones. However data of TATP ( 1 ) obtained in this work revealed insufficient agreement of all sets of data available in literature, which might be explained by the rich polymorphism of TATP 1 . The saturation and diffusion equilibrium concentration of both analytes was calculated at 298.15 K. In comparison to the saturation equilibrium concentration measured in this work ( 1 : 600 μg L⁻¹, 2 : 1589 μg L⁻¹) the corresponding estimated diffusion condition air concentrations ( 1 : 3.1 ng L⁻¹, 2 : 10 ng L⁻¹, for a surface of 200 cm²) are lower by five orders of magnitude.     

Cardanol‐based novolac‐type phenolic resins. I. A kinetic approach

Novolac resins having two different mole ratios of cardanol‐to‐formaldehyde (1:0.6 and 1:0.8) were prepared by using aliphatic tricarboxylic acid as catalyst at four different temperatures ranging between 100 and 130°C with an interval of 10°C. The synthesized novolacs were confirmed by infrared spectroscopic analysis with the appearance of characteristic groups of the novolac resin. The reaction between cardanol (C) and formaldehyde (F) was found to follow second‐order rate kinetics as determined by two different approaches. The over all rate constant (k) increased with the increase of C/F molar ratio. Based on the value of k, various other kinetic parameters such as activation energy (E_a), change in enthalpy (ΔH), entropy (ΔS), and free energy (ΔG) of the reaction were also evaluated. The values of E_a and ΔH were found to be decreased with the increase of C/F molar ratio from 1:0.6 to 1:0.8. These values revealed the nature of the condensation reaction between cardanol and formaldehyde in presence of tricarboxylic acid catalysts. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2730–2737, 2006     

Emulsion of polyurethane having thermosetting properties. II. Relation between the mechanical properties of film and the polyurethane structure

A self-emulsifiable polyurethane emulsion having thermosetting property was prepared by the following procedure: the polyurethane–urea–amine was first prepared by the reaction of diethylene–triamine with a prepolymer containing terminal isocyanate groups in a ketone solvent, and then the primary amino group in the polyurethane–urea–amine was reacted with epichlorohydrin. The mixture was neutralized with an aqueous acid, and finally the ketone solvent was removed by distillation in vacuo. In the polyurethane, polytetramethylene glycol (PTMG) was the base polymer functioning as the soft segment. The present paper reports the effects of the following variables on the mechanical properties of the film prepared from the polyurethane emulsion, i.e., the M _n of PTMG, the molar ratio of diethylene–triamine (DTA) to prepolymer containing terminal isocyanate groups, the structure of the isocyanate end group and the molar ratio of tolylene diisocyanate (TDI) with PTMG. The best elastomer property was realized when M_n of PTMG was 2000, TDI/PTMG molar ratio was 2.0, and prepolymer/DTA molar ratio was 0.85.     

Estimating Ambient Vapor Pressures of Low Volatility Explosives by Rising‐Temperature Thermogravimetry

Vapor pressure is a fundamental physical characteristic of chemicals. Some solids have very low vapor pressures. Nevertheless numerous chemical detection instruments aim to detect vapors. Herein we address issues with explosive detection and use thermogravimetric analysis (TGA) to estimate vapor pressures. Benzoic acid, whose vapor pressure is well characterized, was used to calculate instrumental parameters related to sublimation rate. Once calibrated, the rate of mass loss from TGA measurements was used to obtain vapor pressures of the 12 explosives at elevated temperature: explosive salts – guanidine nitrate (GN); urea nitrate (UN); ammonium nitrate (AN); as well as mono‐molecular explosives – hexanitrostilbene (HNS); cyclotetramethylene‐tetranitramine (HMX), 4,10‐dinitro‐2,6,8,12‐tetraoxa‐4,10‐diaza‐tetracyclododecane (TEX), cyclotrimethylenetrinitramine (RDX), pentaerythritol tetranitrate (PETN), 3‐nitro‐1,2,4‐triazol‐5‐one (NTO), 1,3,3‐trinitroazeditine (TNAZ), triacetone triperoxide (TATP), and diacetone diperoxide (DADP). Ambient temperature vapor pressures were estimated by extrapolation of Clausius‐Clapeyron plots (i.e. ln p vs. 1/T). With this information potential detection limits can be assessed.     

Phase Transformation and Rheological Behaviour of Highly Paraffinic “Waxy” Mixtures

An experimental investigation was undertaken for the rheology and phase transformation of prepared solutions comprising a paraffin wax dissolved in n‐dodecane or n‐hexadecane. The liquid‐solid phase transformation in wax‐solvent mixtures was investigated through the measurement of wax appearance/disappearance temperature (using cross polar microscopy, differential scanning calorimetry, viscometry and a visual method), pour point temperature and crystallization temperature. The results were utilized to prepare a temperature‐composition phase diagram for the wax+n‐C₁₆H₃₄ pseudo‐binary system. The effects of composition, temperature, cooling rate and shear rate were studied on the rheology of wax‐solvent mixtures. A correlation was developed for the apparent viscosity of wax‐solvent mixtures.     

Reactivity of triacetone triperoxide and diacetone diperoxide: Insights from nuclear Fukui function

Triacetone triperoxide (TATP) is more sensitive than diacetone diperoxide (DADP) in the solid-state explosion. To explain this reactivity difference, we analyzed the electronic structures and properties of the crystals of both compounds by using Ab initio method to calculate the structures of their individual molecules as well as their lattice structures and particularly calculating Nuclear Fukui function to gain insight into the sensitivity of the initial, rate-determining step of their decomposition. Our results indicate that TATP and DADP crystal structures exhibit significantly different electronic properties. Most notably, the electronic structure of the TATP crystal shows asymmetry among its reactive oxygen atoms as supported by magnitudes of their nuclear Fukui functions. The greater explosion sensitivity of crystalline TATP may be attributed to the properties of its electronic structure. The electronic calculations provided valuable insight into the decomposition sensitivity difference between TATP and DADP crystals.     

Characteristics of poly(vinyl pyrrolidone)/poly(acrylic acid) interpolymer complex prepared by template polymerization of acrylic acid: Effect of reaction solvent and molecular weight of template

Poly(vinyl pyrrolidone) (PVP)/poly(acrylic acid) (PAA) interpolymer complexes were prepared, in ethanol or dimethylformamide (DMF), by template polymerization of acrylic acid in the presence of PVP (MW: 42.5 or 1100 K) used as the template. FTIR analysis showed that the complexes were formed through hydrogen bonding between the carboxyl groups of the PAA and the carbonyl groups of the PVP. The glass‐transition temperature (T_g) of the complex, prepared in ethanol, was higher than that of the component polymers, whereas the T_g of the complex, prepared in DMF, was located between that of the component polymers. The dissolution rate of the complex was affected by the molecular weight of the PVP and the reaction solvent. The release rate of ketoprofen from the complexes showed a pH dependency, and was slower at a lower pH. The ketoprofen release rate from the complex was controlled mainly by the dissolution rate of the complex above the pK_a of PAA (4.75) and by the diffusion rate below the pK_a. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2390–2394, 2004