Inder Pal Singh Kapoor

Comparative study of chemical composition and antioxidant activity of fresh and dry rhizomes of turmeric (Curcuma longa Linn.).

The phytoconstituents of essential oil and ethanol oleoresin of fresh and dry rhizomes of turmeric (Curcuma longa Linn.) were analyzed by GC-MS. The major constituents were aromatic-turmerone (24.4%), alpha-turmerone (20.5%) and beta-turmerone (11.1%) in fresh rhizome and aromatic-turmerone (21.4%), alpha-santalene (7.2%) and aromatic-curcumene (6.6%) in dry rhizome oil. Whereas, in oleoresins, the major components were alpha-turmerone (53.4%), beta-turmerone (18.1%) and aromatic-turmerone (6.2%) in fresh and aromatic-turmerone (9.6%), alpha-santalene (7.8%) and alpha-turmerone (6.5%) in dry rhizome. Results showed that alpha-turmerone, a major component in fresh rhizomes is only minor one in dry rhizomes. Also, the content of beta-turmerone in dry rhizomes is less than a half amount found in fresh rhizomes. The antioxidant properties have been assessed by various lipid peroxidation assays as well as DPPH radical scavenging and metal chelating methods. The essential oil and ethanol oleoresin of fresh rhizomes have higher antioxidant properties as compared dry ones.

Hexammine metal perchlorates as energetic burning rate modifiers

Abstract Four transition metal hexammine perchlorates namely, [Cu(NH3)6](ClO4)2, [Co(NH3)6](ClO4)2, [Ni(NH3)6](ClO4)2 and [Zn(NH3)6](ClO4)2 have been prepared, characterized and used as ballistic modifiers in the combustion of hydroxy terminated polybutadiene (HTPB)-Ammonium perchlorate (AP) composite solid propellants. Burning rate was considerably enhanced with [Co(NH3)6](ClO4)2 and [Cu(NH3)6](ClO4)2 whereas moderately with [Ni(NH3)6](ClO4)2 and [Zn(NH3)6](ClO4)2 at low concentration (2% by wt). [Co(NH3)6](ClO4)2 was found to accelerate the burning rate by three fold at two percent concentration and it can be exploited as potential energetic burning rate modifier for HTPB-AP propellants. Further, ignition delay studies showed that the deflagration of propellants and AP was accelerated by these additives.

Studies on energetic compounds: Part 8 : Thermolysis of Salts of HNO3 and HClO4

The thermolysis of various substituted ammonium salts of nitric and perchloric acids has been reviewed in the present communication. The mechanistic aspects of thermal decomposition of these salts have been discussed critically. It has been observed that the proton transfer process do play a major role during thermolysis of these salts. The plausible decomposition pathways have also been described.

Studies on energetic compounds. Part 16. Chemistry and decomposition mechanisms of 5-nitro-2,4-dihydro-3H-1,2,4-triazole-3-one (NTO).

The present review deals with the chemistry and thermolysis of NTO and plausible decomposition pathways have been described. The decomposition of 5-nitro-2,4-dihydro-3H-1,2,4-triazole-3-one (NTO) induced by X-ray, UV, laser, photochemical irradiation has also been discussed. High-speed photographic studies of the impact responses of NTO are also included. The thermal decomposition of labelled NTO has also been described here. Methods of detection as well as safe disposal of NTO have also been mentioned.

Kinetics of thermolysis of ring-substituted arylammonium nitrates

Abstract Ring-substituted arylammonium nitrates have been prepared and characterized. Thermal and ignition characteristics of these salts are studied by TG and ignition delay measurements. The ignition temperature (IT), energies of activation (ignition) [( E i ) 21.3–39.3 kJ mol −1 ] were found to be linearly related with the Hammett substituent constant (σ), pK a and oxygen balance of the corresponding nitrate salt. The results suggest that the primary step in the slow and rapid thermolysis of these salts is a proton transfer (NH bond heterolysis) from the arylammonium ion to the nitrate ion.

Thermal analysis of ammonium perchlorate + polystyrene + additive mixtures. I

The thermolysis of ammonium perchlorate (AP) and AP/polystyrene propellants was investigated with carboxylates of copper as additives. The rate of burning was found to be enhanced considerably. TG and ignition delay studies demonstrated that the high-temperature decomposition of AP is enhanced enormously by these additives, whereas the low-temperature decomposition remains unaffected. It is suggested that the main species catalysing the rate of burning or AP decomposition is CuO. Analysis showed that the increase in the rate of burning is controlled by the catalysis of AP decomposition.ZusammenfassungUnter Zusatz von Kupfercarboxylaten wurde die Thermolyse von Ammoniumperchlorat- (AP) und AP/Polystyrol-Treibstoffen untersucht. Die Brenngeschwindigkeit wird erheblich erhöht. TG- und Zündverzugsuntersuchungen zeigen, daß die Zersetzung von AP durch Zusatz dieser Additive bei hohen Temperaturen enorm ansteigt, während sie bei niederen Temperaturen unverändert bleibt. Es wird darauf hingedeutet, daß die wichtigste Komponente zur Katalyse des Brennvorganges bzw. der Zersetzung von AP das Kupferoxid CuO ist. Eine Untersuchung zeigte, daß der Anstieg der Brenngeschwindigkeit durch die Katalyse der Zersetzung von AP bestimmt wird.

Kinetics of thermolysis of ring-substituted arylammonium nitrates 2. TG, DTA, impact, and friction sensitivity studies

Thermolysis of ring-substituted arylammonium nitrates (RSAN) has been carried out by TG, DTA, impact, and friction sensitivity measurements. Although the kinetics of thermal decomposition of these salts was evaluated by fitting TG data in nine mechanism-based kinetic models, the contracting envelopes (n = 2, 3) and Avrami-Erofeev (n = 2, 3) gave the best fit. The activation energies for decomposition (Ed), exothermic decomposition temperatures (Td) (from DTA curves), and impact sensitivity data are found to be linearly related to the Hammett substituent constant (σ) and dissociation exponent (pKa) of the corresponding arylamine. The mechanism of thermolysis of these salts has also been suggested, based on the formation of reaction intermediates during decomposition. A reaction scheme, accounting for the products, is proposed that involves proton transfer, leading to the formation of an arylamine and HNO3 and oxidation of the arylamine by decomposition products of HNO3. The oxidation-reduction reactions, near the surface of the thermolysing material (RSAN), are responsible for the decomposition.

Studies on energetic compounds. Part XI: preparation and thermolysis of polynitro organic compounds.

The thermolysis of high energetic polynitro organic compounds has been reviewed in the present communication.

Studies on energetic compounds Part 3. Kinetics of thermolysis of dimethylanilinium nitrates

Thermolysis of dimethylanilinium nitrates (DMAN) has been carried out by TG, DTA, ignition delay, impact and friction sensitivity measurements. Although kinetics of the thermal decomposition of these salts were evaluated by fitting TG data in nine-mechanism-based kinetic models, only Avrami-Erofeev (n = 2, 3) and contracting area (n = 2) gave the best fits. A reaction scheme accounting for the decomposition products is proposed; it involves proton transfer leading to the formation of an arylamine and HNO3. The other probable routes (evolution of NH3) have also been suggested. The aryl nucleus seems to be oxidized by NO2, HNO3 or its decomposition products prior to ignition, and gaseous products are formed.

Studies on essential oils, part 28 : Chemical composition, antifungal and insecticidal activities of rhizome volatile oil of Homalomena aromatica Schott

HPLC and GC–MS analysis of rhizome oil of Homalomena aromatica showed the presence of 39 components accounting for 96.9% of the total oil. The major component was linalool (62.1%), followed by terpinen-4-ol (17.2%), α-terpineol (2.4%), γ-terpinene (1.9%), α-cadinol (1.5%), geraniol (1.4%), nerol (1.4%), α-terpinene (1.0%), spatulenol (1.0%) and T-cadinol (1.0%). However, the higher percentage of linalool (87.5%) was obtained in HPLC studies. This oil showed good antifungal activity against Curvularia pallescens, Aspergillus niger and Fusarium graminearum as well as also showing insecticidal behaviour against white termite (Odontotermes obesus Rhamb.). Copyright