The unique properties of epoxy polymers have led to their wide application in various fields modern technology. influence the structure bisphenols on polymers, especially thermal ones, is known. However, chemical hardener also affects cured polymers. As hardeners, we used acid hardeners structures: anhydrides maleic, phthalic, pyromellite, methyltetrahydrophthalic and other acids. following giv...

this study was carried out to investigate the effect of esterification on the surface roughness of eastern cottonwood. eastern cottonwood was modified without using any catalyst and solvent at different temperatures and times with two linear chain carboxylic acid anhydrides (acetic anhydride or propionic anhydride). different weight percentage gains (wpgs) were obtained at different conditions....

The mixed anhydrides with N-acyl carbamic acid (IV) were prepared by the reaction of carboxylic acids (Ill) with N-chlorocarbonyl lactams (Ila) or sec. amides (lib). Decarboxylation of IV yielded N-acyl lactams (VI), while symmetrical anhydrides (VII) were obtained by the side reaction of IV with carboxylic acids (III). Aminolysis of IV yielded carboxylic acid amides (IX) in high yield and puri...

A new, highly enantio- and diastereoselective catalytic asymmetric formal cycloaddition of aryl succinic anhydrides and aldehydes which generates paraconic acid (γ-butyrolactone) derivatives is reported.

5(4H)-Oxazolones can be formed through the activation of acylated α-amino acids or of peptide C termini. They constitute potentially activated intermediates in the abiotic chemistry of peptides that preceded the origin of life or early stages of biology and are capable of yielding mixed carboxylic-phosphoric anhydrides upon reaction with phosphate esters and nucleotides. Here, we present the re...

Different succinic anhydrides were used for modification of hydrophobicities of linear and star-shaped poly (e-caprolactone) oligomers with different molecular weights. Hydroxylterminated poly(e-caprolactone) oligomers were acid-functionalized either with succinic anhydride (SAH) or with alkenylsuccinic anhydrides (ASAs) containing 8 or 18 carbons in their alkenyl chains. Hydrophobicities of th...

A convenient method has been developed, which allows for the direct transformation of aryl iodides into the corresponding carboxylic acid anhydrides via Pd-catalyzed carbonylation under atmospheric CO pressure.

We have demonstrated that a pentaerythritol-derivatized hexavanadate can be easily esterified with acid anhydrides using 4-(N,N-dimethylamino)pyridine (DMAP) as a catalyst, which provides a convenient method for the functionalization of polyoxometalates.