Modification of microcrystalline cellulose by a binary mixture of pyromellitic dianhydride and phosphoric acid

The reactions involved in the esteriification of microcrystalline cellulose with a binary mixture of pyromellitic dianhydride and phosphoric acid have been studied. By changing the molar ratio of dianhydride to acid it is possible to regulate the course of the reaction and to obtain products with required contents of phosphoric acid and carboxy groups.Tashkent Institute of Chemical Technology, 700034, Tashkent, ul. Shevchenko, 1. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 583–586, July–August, 1996. Original article submitted January 22, 1996.