Resumen de Synthesis and characterization of new chitosan-o-ethyl phosphonate

Gloria Palma, Pedro Casals, Galo Cardenas

• The chitin is a natural polymer that is extracted commercially from the shells of crustaceans generated as raw material from the fishing industry. Their chemical structure is constituted by residual units of N-acetyl glucosamine linked by b (1 ® 4) and its derivatives can be obtained from alkaline chitosan. The chitin, chitosan and their derivatives present very good perspectives to be used in agriculture. These derivatives are biodegradable and they exhibit fungicides, germicides, nemacides properties and natural defensive mechanisms of the plants. The chlorophosphonic-2-acid (Ethephon®) is a commercial product employed for the early maturation of fruits. The objective of the present work is the synthesis and characterization of chitosan-O-ethyl phosphonate chitosan to obtain a controlled released system with potential plant growth regulation properties. Alkaline chitosan was obtained; and then reacted with the 2-chlorophosphonic acid. The synthesis of new chitosan derivatives and its complete characterization by FT-IR, 13C, ¹H and 31P NMR is described and gas chromatographic, the effects on field blueberries are also tested. A chitosan 99 % deacetylated and Mv = 89,000 g/mol is prepared. The O-(ethyl phosphonic) chitosan (QOEP) with a degree of substitution of 58% is obtained