Thermal Reactions of Bisazides in Resists Containing Double Bonds

1986 ◽  
Vol 76 ◽  
Author(s):  
C. A. Pryde
Keyword(s):  
Thermal Stability ◽  
Ir Spectroscopy ◽  
Thermal Degradation ◽  
Significant Degree ◽  
Thermally Stable ◽  
Double Bonds ◽  
Thermal Reactions ◽  
Thermal Addition ◽  
Derivatives Of ◽  
Thermal Stability Of

ABSTRACTDerivatives of 2,6-bis(4-azidobenzylidene) cyclohexanone are frequently used as photosensitizers in photoresists. These compounds are generally considered to be quite thermally stable. However, there have been reports of thermal degradation occurring at temperatures as low as 60'C.Experiments done here suggest that the thermal stability of the azide is adversely affected by the presence of unsaturated material in the formulation. Data from IR spectroscopy show that, by itself, 2,6-bis(4-azidobenzylidene) 4-methylcyclohexanone is thermally stable in a polyamic acid film at 75–80° C. However, addition of a monomeric aminoacrylate to the formulation results in a significant decay in the absorption of the azide moiety in just a few hours at these same temperatures. This decay is attributed to reaction of the sensitizer with the acrylate double bonds. In a thick film, which might require a 1–2 hour prebake, this thermal addition could result in a significant degree of crosslinking and thus to decreased contrast in the final pattern.

scholarly journals LNA units present in [RP-PS]-(DNA#LNA) chimeras enhance the thermal stability of parallel duplexes and triplexes formed with (2′-OMe)-RNA strands

RSC Advances ◽  
2020 ◽  
Vol 10 (38) ◽  
pp. 22370-22376
Author(s):  
Katarzyna Jastrzębska ◽  
Barbara Mikołajczyk ◽  
Piotr Guga
Keyword(s):  
Thermal Stability ◽  
Thermally Stable ◽  
Derivatives Of ◽  
Thermal Stability Of

3′-O-(2-Thio-1,3,2-oxathiaphospholane) derivatives of 5′-O-DMT-LNA-nucleosides were used to prepare P-stereodefined (RP-PS)-DNA#LNA chimeras, which form thermally stable parallel complexes with (2′-OMe)-RNA matrices.

Oligomers with structural elements of imidazolidinetrione obtained from oxamic acid and oxamide: polyurethane foams modified by structural elements of imidazolidinetrione

2015 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Iwona Zarzyka
Keyword(s):  
Thermal Stability ◽  
Polyurethane Foams ◽  
Thermally Stable ◽  
Structural Elements ◽  
Derivatives Of ◽  
Thermal Stability Of

Abstract Hydroxyalkyl derivatives containing oxamidoester and oxamide fragments have been separately obtained using oxamic acid, oxamide and alkylene carbonates. It has been proven that the presence of oxamidoester and oxamide structural fragments in oligomer structures is responsible for the thermal stability of these products. Rigid, thermally stable polyurethane foams were obtained with the use of oligomers with oxamidoestercarbamidoimide, carbamide, oxamidoester and oxamide groups as polyols components. The properties of these foamed materials were compared with each other and with the properties of reference foams. It was found that the polyurethane foams characterized by the best properties were obtained from hydroxypropyl derivatives of oxamide.

Flammability and Thermal Degradation of Polystyrene/Cadmium Sulfate Nanocomposites

2013 ◽  
Vol 820 ◽  
pp. 84-87
Author(s):  
Zheng Zhou Wang ◽  
Charles A. Wilkie
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Cone Calorimeter ◽  
Cds Nanoparticles ◽  
Solvothermal Process ◽  
Cadmium Sulfate ◽  
Peak Heat Release Rate ◽  
Microscale Combustion Calorimeter ◽  
Combustion Calorimeter ◽  
Thermal Stability Of

Cadmin sulfate nanoparticles, hollow sphere (CdS-HS) and rode (CdS-NR) were synthesized by ultrasonic and solvothermal process, respectively. The effect of the two kinds of nanoparticles on flammability of polystyrene was investigated using cone calorimeter (Cone) and microscale combustion calorimeter (MCC). Cone data indicate that the incorporation of 1% CdS nanoparticles leads to a about 20% reduction in the peak heat release rate (PHRR) compared to the pure PS; CdS-NR is more efficient in reducing the PHRR proved by both Cone and MCC results. The TG results show that the addition of the nanoparticles mainly increases thermal stability of PS at high temepratures.

Preparation and Pyrolysis of Stereoisomeric Bromobicyclo[n.1.0]alkanes ( n = 6, 8 , 10)

1987 ◽  
Vol 42 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Eckehard V. Dehmlow ◽  
Roland Kramer
Keyword(s):  
Thermal Stability ◽  
Gas Phase ◽  
Condensed Phase ◽  
Secondary Products ◽  
Gas Phase Reactions ◽  
Stereoselective Reduction ◽  
Derivatives Of ◽  
Thermal Stability Of

Abstract The title compounds la-3c were prepared by stereoselective reduction of the respective dibromides. Pyrolysis gave allylic bromides (8, 9, 11) as primary and dienes (10, 12) as secondary products. Product ratios were independent of the stereochemistry of the starting materials. No differences of the rearrangement rates of the stereoisomers were observed in gas phase reactions of the derivatives of bicyclo[6.1.0]- and bicyclo[8.1.0]alkanes. With the larger bicyclo[10.1.0] derivatives, however, distinct differences in the thermal stability of cis-trans-isomers4c/5c or 2c/3c were found in condensed phase.

scholarly journals The Thermal Stability of Aviation Fuel

1984 ◽  
Author(s):  
J. S. Mills ◽  
F. R. Edwards
Keyword(s):  
Thermal Stability ◽  
Research Tool ◽  
Aviation Fuel ◽  
Engine Oil ◽  
Thermally Stable ◽  
Fuel System ◽  
Flow Rates ◽  
Aircraft Fuel ◽  
Oil Cooler ◽  
Thermal Stability Of

The propensity of aviation turbine fuels to produce deposits in the oil-cooler and filter sections of aircraft fuel systems has been examined using a rig that simulates the fuel system of an aircraft and which employs realistic flow rates. All the fuels examined were found to be thermally stable up to temperatures in excess of those currently attained in engine oil coolers. Comparison with results obtained with the JFTOT indicates that this is not suited for use as a research tool.

scholarly journals The Use of POSS-Based Nanoadditives for Cable-Grade PVC: Effects on its Thermal Stability

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1105 ◽  
Author(s):  
Palin ◽  
Rombolà ◽  
Milanesio ◽  
Boccaleri
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Additive Effects ◽  
Poly Vinyl Chloride ◽  
The Family ◽  
Mechanical Performances ◽  
Oligomeric Silsesquioxane ◽  
Thermal Stability Of

Plasticized–Poly(vinyl chloride) (P-PVC) for cables and insulation requires performances related to outdoor, indoor and submarine contexts and reduction of noxious release of HCl-containing fumes in case of thermal degradation or fire. Introducing suitable nanomaterials in polymer-based nanocomposites can be an answer to this clue. In this work, an industry-compliant cable-grade P-PVC formulation was added with nanostructured materials belonging to the family of Polyhedral Oligomeric Silsesquioxane (POSS). The effects of the nanomaterials, alone and in synergy with HCl scavenging agents as zeolites and hydrotalcites, on the thermal stability and HCl evolution of P-PVC were deeply investigated by thermogravimetric analysis and reference ASTM methods. Moreover, hardness and mechanical properties were studied in order to highlight the effects of these additives in the perspective of final industrial uses. The data demonstrated relevant improvements in the thermal stability of the samples added with nanomaterials, already with concentrations of POSS down to 0.31 phr and interesting additive effects of POSS with zeolites and hydrotalcites for HCl release reduction without losing mechanical performances.

scholarly journals Exploring the Complexation of Counterion in Novel Family of Polyelectrolytes with Unexpected Solubility Behaviour

2020 ◽  
Vol 869 ◽  
pp. 61-68
Author(s):  
Egor A. Bersenev ◽  
Alina Maryasevskaya ◽  
Evgenii V. Komov ◽  
Denis V. Anokhin ◽  
Dimitri A. Ivanov
Keyword(s):  
Thermal Stability ◽  
Ir Spectroscopy ◽  
Lithium Salt ◽  
Ionic Form ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alkali Ions ◽  
In Series ◽  
Chelating Complex ◽  
Thermal Stability Of

In the present paper we study the effect of complexation in linear negatively charged polyelectrolytes with different alkali ions. With combination of IR-spectroscopy, X-ray diffraction and nanocalorimetry, we attempted to explain unusual solubility, crystallinity and thermal stability of these polymers. The increase of thermal stability and insolubility in water in series of semi-crystalline polysalts as K+ ≤ H+ <Na+ was explained by effectiveness of formation of chelating complex. Insoluble in water sodium salt shows the highest thermal stability of crystal phase up to . In contrast, well soluble in water amorphous lithium salt does not self-organize in chelating complex and is presented in ionic form.

scholarly journals Development of Novel Silica-Based Formulation of α-Lipoic Acid: Evaluation of Photo and Thermal Stability of the Encapsulated Drug

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 228 ◽  
Author(s):  
Ekaterina S. Dolinina ◽  
Elizaveta Yu. Akimsheva ◽  
Elena V. Parfenyuk
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Lipoic Acid ◽  
Sol Gel ◽  
Silica Matrix ◽  
Matrix Modification ◽  
Drug Stabilization ◽  
Further Development ◽  
Kinetics Of ◽  
Thermal Stability Of

Powerful antioxidant α-lipoic acid (LA) is easily degraded under light and heating. This creates difficulties in its manufacture, storage and reduces efficiency and safety of the drug. The purpose of this work was to synthesize novel silica-based composites of LA and evaluate their ability to increase photo and thermal stability of the drug. It was assumed that the drug stabilization can be achieved due to LA-silica interactions. Therefore, the composites of LA with unmodified and organomodified silica matrixes were synthesized by sol-gel method at the synthesis pH below or above the pKa of the drug. The effects of silica matrix modification and the synthesis pH on the LA-silica interactions and kinetics of photo and thermal degradation of LA in the composites were studied. The nature of the interactions was revealed by FTIR spectroscopy. It was found that the rate of thermal degradation of the drug in the composites was significantly lower compared to free LA and mainly determined by the LA-silica interactions. However, photodegradation of LA in the composites under UV irradiation was either close to that for free drug or significantly more rapid. It was shown that kinetics of photodegradation was independent of the interactions and likely determined by physical properties of surface of the composite particles (porosity and reflectivity). The most promising composites for further development of novel silica-based formulations were identified.

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