MECHANISTIC STUDY OF POLYNITROCOMPOUNDS BY XPS——MECHANISM OF THE THERMAL DECOMPOSITION OF POLYNITROPHENOLS

The subject-matter described in the paper reveals the importance of the hydroxyl groups within the molecules of polynitrophenols in the process of the thermal decomposition as studied by XPS (ESCA). It is evident that theintramolecular charge transfer with drastic change during the time of the thermal decomposition can be envisaged as an indicator capable of following the reaction process. The present work shows that combining with CNDO/2 SCF MO model XPS data allow information to be derived reasonably on the relative stability of nitrogen-containing species left in the surface of the energetic materials during decomposition.     

IN SITULASER RAMAN SPECTROSCOPY OF THERMAL DECOMPOSITION OF AMMONIUM TUNGSTATE

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THE PROCESS OF THE EMULSIFIER-FREE POLYMERIZATION IN THE PRESENCE OF BARIUM SULFATE POWDER

The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K_sS_sO_s-water in thepresence of Barium Sulfate(BS)powder was investigated under varied conditions within the range of BSpowder quantity,initiator concentration and reaction temperature.Experimental results showed thatthe rate of polymerization is proportional to 0.3-power of the BS quantity and 1.3-power of theinitiator concentration.There is a linear relationship of 2/3-power for the conversion and time.Aprocess for the polymerization is propose to explain the experimental results.     

THE EFFECTS OF IRRADIATION ON THE THERMAL PROPERTIES OF SEMI-CRYSTALLINE POLYAMIDES

Irradiation crosslinking of semi-crystalline polyamides was performed by high energy electronswith various dosages. It is known that the melting behavior of the polymers after irradiation is acomplex phenomenon. In company with the wide angle X-ray diffraction and DSC data of irradiatedand unirradiated polyamides it is possible to develop the local order and perfection of the crystallinitiesslightly which resulted from introduction of intermolecular crosslinking in amorphous region, incl-uding in amorphous-crystalline interface and crystalline defect regions due to irradiation. It canbe explained that slight increase of melting temperature (T_m) and heat of fusion (△H_f) with increasingdosage for both of higher crystallinity nylon 4 and nylon 6. For irradiated lower crystallinity nylons,in contrast, the T_m and △H_f decrease obviously with increasing dosage. In this case, radiation cross-linking "freeze in" the pre-existing morphology, and then the prevention for reorganization duringheating is a dominant effect. The T_m from the second melting for all of the samples were depressed,corresponding with Flory theory. Therefore the crosslinks imposed on the molecules restrainedthe molecular mobility, and that not only depresses the crystallinity but also increases the imperfec-tion of crystallites when the radiated polymer melted and then recrystallized. These are also reflectedin the depression of heat and entropy of fusion as well as the appearance of double melting peakson the DSC thermograms.     

STUDY ON THERMAL DECOMPOSITION KINETICS OF URUSHIOL METAL CHELATE POLYMERS

The thermal decomposition kinetics of urushiol-Cu, urushiol-Nd and urushiol-Ti chelatepolymers has been studied by non-isothermal thermogravimetry. The results suggest that thethermal decomposition kinetics of three chelate polymers are all of first order. Their averageactivation energy values of the thermal decomposition calculated by Ozawa-(I) method are 110,79, 136. 98 and 163. 64 kJ mol~(-1) respectively, which increase linearly with the metal valence of themetal chelate polymers     

PREPARATION OF V_2O_3 BY THERMAL DECOMPOSITION OF HYDRAZINE-CONTAINING VANADIUM SALT

A new method of preparing V_2O_3 by thermal decomposition from hydrazine-containing vanadium salt was described. The process was investigated by thermal analysis (TG and DSC) and the thermally decomposed product was studied by S.E.M., chemical analysis and X-ray diffraction. The result indicated that the product obtained in this way was V_2O_3.     

EFFECT OF HYDRATION ON THE THERMAL STABILITY OF ENZYME

The thermal stability of New Zealand culture rabbit muscle aldolase wasinvestigated by differential scanning calorimetry in the water content range0.23-3.70 g water per g protein.The experimental results showed that at watercontents below 0.47g/g,an endothermic peak was observed and at water contentsabove 0.57g/g,an endothermic and an exothermic peak were both observed on DSCthermogram.Thermal denaturation result of the enzyme and the relationshipbetween two transition temperatures and water contents were first reported inthis paper.Up to now we have not seen any similar reports concerning theexothermic transition.     

SOAPLESS EMULSION COPOLYMERIZATION IN THE PRESENCE OF BARIUM SULFATE POWDER

To investigate soapless emulsion copolymerization in the presence of a solid phase,copolymerization experiments were carried out for the styrene-butyl acrylate-K_2S_2O_8-watersystem by using barium sulfate powder,which is assumed to be chemically inert.Reactionconditions were varied with respect to barium sulfate powder quantity,initiator concen-tration and temperature.These factors were investigated with respect to the effect onreaction rate and conversion,polymer particle number and diameter,and latex stability.     

THERMAL DECOMPOSITION OF METAL COMPLEXES. MIXED COMPLEXES OF DIVALENT TRANSITION METALS WITH α-NITROKETONES

Abstract

The thermal behaviour of mixed complexes containing transition metals, α-nitroketones and pyridine or ethanol was investigated by thermogravimetric analysis (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The values of the activation energies and the enthalpies for the dissociation processes have been calculated in high vacuum and isothermal conditions. Comments are made on the obtained heats and correlations with structural characteristics are looked for.     

PREPARATION OF FINE α-AL_2O_3 BY THERMAL DECOMPOSITION OF HYDRAZINE-CONTAINING ALUMINUM SALT

A new method for preparing fine -Al_2O_3 by thermal decompositionfrom hydrazine-containing aluminum salt was described.The process of thethermal decomposition of the hydrazine-containing aluminum salt wasinvestigated by thermal analysis(TG and DTA)and the thermally decomposedproducts were studied by S.E.M and X-ray diffraction.The result indicatedthe particles of -Al_2O_3 obtained in this way at 12500℃ were<1um in size.     

PREPARATION OF ELECTRICAL CONDHCTIVE MOLYBDENUM OXIDE BY THERMAL DECOMPOSITION OE HYDRAZINE-CONTAINING MOLYBDENUM SALT

A new method of preparing electrical conductive molybdenumoxide by thermal decomposition from hydrazine-containing molybdenum saltwas described.The process of the thermal decomposition of hydrazine-containing molybdemum salt was investigated by thermal analysis(TG and DTA)and the thermally decomposed product was studied by S.E.M.and chemicalanalysis.The result indicated that the molybdenum oxide obtained in thisway was electrical conductive.     

A THEORETICAL STUDY OF THE THERMODYNAMIC AND KINETIC PROPERTIES FOR THE REACTION OF FORMYL CYANIDE DECOMPOSITION

We compute the thermodynamic and the kinetic properties for the reaction:HCOCN→HCH+CO using the statistical theory and the transition-state theory.The equi-librium constants and the rate coefficients of this reaction are also reported here,andthe half lives of formyl cyanide at different temperatures are first estimated in thiswork.     

INFLUENCE OF THERMAL AND NON—THERMAL EFFECTS OF ULTRASOUND ON ISOTHERMS OF PHENOL ON NKAⅡ RESIN

Adsorption equilibrium experiments of phenol on the NKA II resin are separately conducted in the presence and absence of ultrasound at ambient temperature.The isotherm of phenol on the polymer adsorbent in the presence of ultrasonic field is firstly reported.Results indicated that the isotherm of phenol determined in the presence of ultrasound is lower than that in the absence of ultrasound.In addition,experiments also show that the use of ultrasound to the adsorption system of the phenol aqueous solution and NKA Ⅱ resin could cause the rising of the temperature of the system in the order of 6^-C.The effect of ultrasound on the isotherm of the phenol on the NKA Ⅱ resin mostly ascribes to the thermal effect and the non-thermal effect of ultrasonic field.and the role of the later is greater than that of the former.     

STUDY ON THE KINETICS OF POLYMERIZATION OF MMA BY COPPER（Ⅱ） CHELATING RESINS

The polymerization of MMA initiated by copper(Ⅱ） chelating resins/CCl4 system was studied.From the kinetic data,the kinetic equation of polymerization can be expressed as Rp=Ke^-56400/RT[MMA]^1.57[CCl4]^m[RESIN-Cu]^0.18 where m:3-4.5,when[CCl4] 0.1-6.93M.The free radical polymerization mechanism is proposed.The primary radicals are formed by the process of complexation-chlorine transformation among the copper(Ⅱ) chelating resin,CCl4 and methacrylate.     

STUDIES OF THE MOBILITY OF SURFACE CARBON FORMED BY THE DECOMPOSITION OF METHANE ON SUPPORTED TRANSITION METAL CATALYSTS

IntroductionInformationonrelativereactiviticsofsuffocccarbonfromthcdecompositionofmethaneontransitionmetalcataIystspla}.simportantruleinourunderstandingthenatllreofeffcctiveutiliZaionofmethane.Asignificantamountofdataonthissubjecthavealread}'bccnaccumulatcd.Itx"asdiscovercdthatrcactiviticsofthesuffocecarbonstrongl}'dependonthcstructuralparameters-suchasthctyPcofsuffocecarbon.thestrengthofsurfacecarbon-metalinteractionsandthetendencyoftransformationamongthemll'2].0fspecialsarcthatthenatureofth…     

ESTIMATION OF THE CRITICAL RATE OF TEMPERATURE INCREASE OF THERMAL EXPLOSION OF NITROCELLULOSE USING NON-ISOTHERMAL DSC

A method of estimating the critical rate of temperature increase of thermal explosion for the first orderautocatalytic decomposition reaction system using non-isothermal DSC is presented. Information is obtained on theincreasing rate of temperature in nitrocellulose containing 13.54% of nitrogen when the first order autocatalytic decomposition converts into thermal explosion.     

APPLICATION OF THERMAL ANALYSIS TO THE QUICK DETERMINATION OF THE PROXIMATE ANALYSIS ITEMS AND CALORIC VALUE FOR COAL

A research on the application of a TG-DTA(thermal gravimetryaifferential thermal analysis)to the quick determination of moisture,organic volatilefixed carbon,ash and caloric value for coal is described.     

STUDIES ON THE NON－ISOTHERMAL KINETICS OF THERMAL DECOMPOSITIONS OF THE COMPLEXES OF Cd（II）WITH O－VANILLIN THIOSEMICARBAZONE AND IRON（III）WITH 2－［（O－HYDROXYBENZYLIDENE）AMINO］PHENOL AND PYRIDINE

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STUDY OF THE CORRELATION BETWEEN THE STRUCTURE OF THE [Ir(сod)Cp] COMPLEX AND ITS THERMAL PROPERTIES

Journal of Structural Chemistry - A volatile iridium(I) complex [Ir(cod)Cp] (cod - 1,5-cyclooctadiene, Cp - cyclopentadienyl) is synthesized and characterized by IR and NMR spectroscopy. The...     

THERMAL STRUCTURE OF THE CRUST AND UPPER MANTLE OF LIAOHE RIFT BASIN, NORTH CHINA

On the basis of analysing terrestrial heat flow and mantle heat flow values, the crustal temperatureat depth was calculated for Liaohe Rift Basin in North China, and a conceptual model of thermal struc-ture of the crust and upper mantle of the Basin has been suggested. Results indicate that Liaohe Basinis characterized by a relatively high mantle heat flow (0.98 HFU) but low crustal heat flow (0.57HFU),both caused by upwelling of the asthenosphere and crustal thinning during rifting process in early Eo-gene in thc region studied. This sort of thermal structure of the crust and upper mantle seems to beinherent in the region in between tectonically stable and active areas and has been considered to be theproduct of the history of geological evolution of the Basin since Mesozoic era.