POLYMER BULLETIN, cilt.41, sa.5, ss.577-584, 1998 (SCI-Expanded)
The aim of this work was to test the application of new copolymeric poly(acrylamide/ crotonic acid) (AAm/CA) hydrogels to agrochemicals (sodium 2,2 dichloropropionate (dalapon), ammonium nitrate, potassium nitrate and ammonium sulfate) releases. AAm/CA hydrogels containing a,agrochemicals is prepared by two different composition of crotonic acid and two different gamma-rays doses. The herbiside such as sodium 2,2 dichloropropionate (dalapon) and fertilizers such as ammonium nitrate, potassium nitrate and ammonium sulfate were trapped in the gels by including it in the feed mixture of radiation polymerization. The equilibrium swelling degree in water was between 1020% and 1840%. The swelling kinetics of the hydrogels were studied at 25 degrees C, and the initial swelling rate, swelling rate constant, maximum swelling, diffusional exponent and diffusion coefficient of the process were obtained. The concentration of the released of agrochemicals from the hydrogels was determined by conductivity measurements. The initial releasing rate, release rate constant, maximum concentration of releasing agrochemicals were calculated. As a result, if AAm/CA hydrogels containing agrochemicals were swelled in water, release of agrochemicals was increased with the raising of crotonic acid quantities in the hydrogel and gamma-rays doses.