Electric Literature of 18959-30-3, Chemistry is the science of change. But why do chemical reactions take place? Why do chemicals react with each other? The answer is in thermodynamics and kinetics.In a document type is Article in Press, and a compound is mentioned, 18959-30-3, 4,5-Difluorophthalic Anhydride, introducing its new discovery.
The thermal oxidative stability of a 4-phenylethynyl phthalic anhydride (PEPA) endcapped polyimide (PI) was investigated. A surface reaction layer formed due to oxidization during thermal aging and grew in thickness with increasing aging time. Analysis of the surface layer revealed a partial loss of aromatic ring, ether linkage, and imide linkage in the aged polymer. The partial loss of the imide linkage and ether linkage in the surface layer was corroborated by the observed release of carbon monoxide and carbon dioxide reaction products. The oxidized layer exhibited discoloration and an increase in glass transition temperature. The surface discoloration was attributed to the formation of the conjugated unsaturated or aromatic carbonyl groups and/or the charge transfer complex. Interior regions of the oxidized samples were largely unaffected, except for a more compact molecular configuration. Compared with aging at high temperatures (288C, 316C), aging at 204C produced similar chemical changes in the cured polymer, albeit with a low degradation rate. The oxidative stability of the imide polymer surpassed that of conventional nadic-endcapped PIs due to the greater intrinsic thermal stability of the PEPA endcap. The unusual oxidative stability of the PI, combined with superior mechanical properties, warrant consideration as a composite matrix for future applications in high-temperature service conditions.
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Electric Literature of 18959-30-3. In my other articles, you can also check out more blogs about 18959-30-3
Reference：
Benzofuran – Wikipedia,
Benzofuran | C8H2948O – PubChem