scholarly journals Identification of the molecular-weight growth reaction network in counterflow flames of the C3H4 isomers allene and propyne

2020 ◽  
Author(s):  
G. Kukkadapu ◽  
S.W. Wagnon ◽  
W.J. Pitz ◽  
N. Hansen
Keyword(s):  
Molecular Weight ◽  
Reaction Network ◽  
Weight Growth ◽  
Growth Reaction ◽  
Counterflow Flames

The role of alkoxy radicals in the heterogeneous reaction of two structural isomers of dimethylsuccinic acid

2015 ◽  
Vol 17 (38) ◽  
pp. 25309-25321 ◽  
Author(s):  
Chiu Tung Cheng ◽  
Man Nin Chan ◽  
Kevin R. Wilson
Keyword(s):  
Molecular Weight ◽  
Hydroxyl Radicals ◽  
Heterogeneous Reaction ◽  
Methyl Groups ◽  
Structural Isomers ◽  
Alkoxy Radicals ◽  
Weight Growth ◽  
Bond Scission

The heterogeneous reaction of hydroxyl radicals with two isomers of dimethylsuccinic acid is used to explore how the location of branched methyl groups controls C–C bond scission and molecular weight growth reactions.

scholarly journals 1,3-Dioxolan-4-Ones as Promising Monomers for Aliphatic Polyesters: Metal-Free, in Bulk Preparation of PLA

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2396
Author(s):  
Stefano Gazzotti ◽  
Marco Aldo Ortenzi ◽  
Hermes Farina ◽  
Alessandra Silvani
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Acid Catalyst ◽  
Monomer Conversion ◽  
Reaction Conditions ◽  
Aliphatic Polyesters ◽  
Metal Free ◽  
Weight Growth ◽  
Double Activation

The first example of solvent-free, organocatalyzed, polymerization of 1,3-dioxolan-4-ones, used as easily accessible monomers for the synthesis of polylactic acid (PLA), is described here. An optimization of reaction conditions was carried out, with p-toluensulfonic acid emerging as the most efficient Brønsted acid catalyst. The reactivity of the monomers in the tested conditions was studied following the monomer conversion by 1H NMR and the molecular weight growth by SEC analysis. A double activation polymerization mechanism was proposed, pointing out the key role of the acid catalyst. The formation of acetal bridges was demonstrated, to different extents depending on the nature of the aldehyde or ketone employed for lactic acid protection. The polymer shows complete retention of stereochemistry, as well as good thermal properties and good polydispersity, albeit modest molecular weight.

Isolation and characterization of a low molecular weight growth-promoting factor from human plasma

Life Sciences ◽  
1987 ◽  
Vol 41 (3) ◽  
pp. 297-304 ◽  
Author(s):  
M.H. Heulin ◽  
J. Rajoelina ◽  
M. Artur ◽  
C. Geschier ◽  
J. Straczek ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Human Plasma ◽  
Low Molecular Weight ◽  
Weight Growth ◽  
Isolation And Characterization ◽  
Growth Promoting

Ab initio study of the influence of resonance stabilization on intramolecular ring closure reactions of hydrocarbon radicals

2016 ◽  
Vol 18 (12) ◽  
pp. 8437-8452 ◽  
Author(s):  
Kun Wang ◽  
Stephanie M. Villano ◽  
Anthony M. Dean
Keyword(s):  
Molecular Weight ◽  
Ab Initio ◽  
Low Energy ◽  
Ring Closure ◽  
Ab Initio Study ◽  
Cyclization Reactions ◽  
Weight Growth ◽  
Resonance Stabilization ◽  
Hydrocarbon Radicals ◽  
Intramolecular Ring

The cyclization reactions of dieneyl radicals provide a low energy route to the formation of molecular weight growth products.

scholarly journals ROAD BITUMEN WITH A MAN-MADE MODIFIER

Neft i gaz ◽  
2020 ◽  
Vol 3-4 (117-1118) ◽  
pp. 118-124
Author(s):  
N.K. ISHMUHAMEDOVA, ◽  
Keyword(s):  
Molecular Weight ◽  
Structure Formation ◽  
Elemental Sulfur ◽  
Oil And Gas ◽  
Raw Materials ◽  
Reaction System ◽  
Component Composition ◽  
Oil Field ◽  
Technological Parameters ◽  
Weight Growth

In this work, for the development of oil bitumens, the high-tar oil of the Karazhanbas field, which is economically unprofitable for processing, is used as an additive to the tar of a mixture of oils of Martyshi + Mangystau. As a modifying and plasticizing agent, a technogenic modifier – elemental sulfur (waste from the Tengiz oil and gas processing complex) was used, and various induction moments were introduced, which are an additional source of structure formation of the oxidized feedstock. The Karazhanbas oil field, although economically unprofitable for processing, is unique in its component composition. It contains a large number of high-molecular and resinous-asphaltene components (resins 24,18% and asphaltenes 4,85%) prone toassociative interactions and structure formation. Asphaltenes, in turn, are stabilizers of molecular weight growth, and, in general, make a significant contribution to improving the technological parameters of the target product-bitumen. The mechanism of action of elemental sulfur is that when dispersed with a reaction mixture, there is an increase in the release of acid gases, such as: H2S, CO, SO2, which is explained by an increase in the rates of polycondensation and compaction reactions. This increases the rate of reaction of bitumen sulphurization in the reaction system. Over time, the intensity of gas release decreases due to a gradual decrease in the rates and further cessation of compaction and polycondensation reactions. The structure of the bitumen stabilizes. Induction moments were used as an additional object of the structure builder. The creation of the induction factors increased the amount of reactive monocularity and bicyclogermacrene hydrocarbons (as confirmed by the indicators of instrumental analysis) that accelerate the formation of high molecular compounds, which leads to increased molecular weight of oxidizable starting material, thereby improving the technological parameters of the resulting bitumen. Technogenic sulfur and induction moments in tandem have a combined effect on the physical and mechanical characteristics of the developed bitumen. Summarizing the above results of experimental work, it should be noted that by choosing the calculated amount of raw materials, additives and varying various induction moments, you can get bitumen of the BN 80/120 brand, and this makes it possible to dispose of man-made waste, which is economically and environmentally appropriate.

scholarly journals Molecular Weight Growth in the Gas-Phase Reactions of Dehydroanilinium Radical Cations with Propene

2019 ◽  
Vol 123 (41) ◽  
pp. 8881-8892 ◽  
Author(s):  
Patrick D. Kelly ◽  
Cameron C. Bright ◽  
Stephen J. Blanksby ◽  
Gabriel da Silva ◽  
Adam J. Trevitt
Keyword(s):  
Molecular Weight ◽  
Gas Phase ◽  
Radical Cations ◽  
Gas Phase Reactions ◽  
Weight Growth

Counterflow flames of ultrahigh-molecular-weight polyethylene with and without triphenylphosphate

2016 ◽  
Vol 169 ◽  
pp. 261-271 ◽  
Author(s):  
O.P. Korobeinichev ◽  
M.B. Gonchikzhapov ◽  
A.A. Paletsky ◽  
A.G. Tereshchenko ◽  
I.K. Shundrina ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Ultrahigh Molecular Weight ◽  
Counterflow Flames
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