Controlled-release systems based on the intercalation of polymeric metribuzin onto montmorillonite

A series of polymer-clay composites carrying metribuzin as herbicide moieties were prepared. Linear copolymers containing metribuzin via an imide linkage were prepared by the free-radical polymerization of metribuzin monomer (ATN-diacryloyl metribuzin) with different comonomers. The intercalation of the copolymers onto montinorillonite through a cationic exchange process was carried out and yielded metribuzin composite products. The prepared materials were characterized with a wide variety of analytical techniques, including gel permeation chromatography, NMR, IR, elemental microanalysis, gravimetric analysis (calcination), and swelling measurements. The release rates for the prepared materials were investigated in media of different pHs with an ultraviolet spectrophotometer. Also, these compounds were studied for the control of herb growth. (C) 2002 Wiley Periodicals, Inc.