Sulfluramid volatility reduction by beta-cyclodextrin.
Sulfluramid is an expensive active principle of insecticidal baits that is lost by volatilization during the pelletization of baits. To increase the thermal stability of sulfluramid, we tested its molecular encapsulation in beta-cyclodextrin (beta-CD), using molar ratios of 1:1 and 1:2 (sulfluramid:beta-CD), using the complex preparation techniques of coprecipitation and kneading. The physical mixture of sulfluramid and beta-CD was also tested for comparison. The products of complexation were characterized by differential scanning calorimetry, thermogravimetry, and derivative thermogravimetry, indicating the formation of a sulfluramid/beta-CD complex and showing that the release of the complexed sulfluramid occurs in the range of 270-300 degrees C, a temperature range that is well above the temperature at which sulfluramid sublimates (40 degrees C). This result warrants a reduced sulfluramid loss in the preparation of insecticidal baits. The preparation of the complex by kneading with molar ratio of 1:2 gave the highest yield of complex, about 64%, in relation to the theoretical maximum.
Bergamasco
Rita de Cássia
Rde C
State University of Maringa, Department of Chemical Engineering, Av. Colombo 5790, BL D-90, CEP 87020-900, Maringa, Brazil.
Zanin
Gisella Maria
GM
de Moraes
Flavio Faria
FF
D002152:Calorimetry, Differential Scanning; D005466:Fluorocarbons / Q000737:chemistry*; D006358:Hot Temperature; D015394:Molecular Structure; D013449:Sulfonamides / Q000737:chemistry*; D013818:Thermogravimetry; D014835:Volatilization; D047392:beta-Cyclodextrins / Q000737:chemistry*
D005466:Fluorocarbons; D013449:Sulfonamides; D047392:beta-Cyclodextrins; C063732:sulfluramid; C031215:betadex