22770-13-4Relevant academic research and scientific papers
Reevaluation of Tetrahydrophthalic Anhydride as an End Cap for Improved Oxidation Resistance in Addition Polyimides
Meador, Mary Ann B.,Frimer, Aryeh A.,Johnston, J. Christopher
, p. 1289 - 1296 (2004)
Several substituted 1,2,3,6-tetrahydrophthalic anhydride end caps, including the 3-phenyl, 3-methoxy, 3-trimethylsilyloxy, and 3,6-diphenyl analogues, were synthesized via the Diels-Alder condensation of the corresponding butadienes and maleic anhydride. These anhydrides, as well as the commercially available 3-hydro and 4-methyl analogues, were each ground up together with methylenedianiline in a 2:1 ratio and heated gradually from 204 to 371°C, with the thermolysis followed by NMR. Generally speaking, a transformation via monoimide to bisimide was observed in the lower temperature range, followed by competition between cross-linking and aromatization. We believe that this competition produces a substantial percentage of aromatic product, with the concomitant lowering of the relative amount of cross-linking and is responsible for both improved thermooxidative stability of tetrahydrophthalic end-capped polyimides and their substantial frangibility. The thermolysis of the tetrahydrophthalimides under an inert atmosphere dramatically lowers the amount of aromatization; hence, the mechaniam for aromatization is an oxidative one.
Reaction of trans,trans-1,4-Diphenylbutadiene and Maleic Anhydride. Substituent and Solvent Effects
Ballistreri, Francesco P.,Maccarone, Emanuele,Perrini, Giancarlo,Tomaselli, Gaetano A.,Torre, Michele
, p. 273 - 278 (2007/10/02)
Diels-Alder adducts from X-substituted diphenylbutadienes (X=p-NMe2, p-OMe, p-Me, m-OMe, H, p-Cl, m-Cl, p-CN, and m-NO2) and maleic anhydride, and from diphenylbutadiene and some dienophiles (N-methylmaleimide, N-phenylmaleimide, and 1,4-benzoquinone), ha
