| Very little permeation work has addressed the breakthrough of a complex mixture such as a commercial pesticide formulation through protective glove materials. To evaluate the factors that affect the breakthrough time of the pesticide active ingredient, the ASTM permeation cell system was used with two thicknesses of butyl rubber, three common pesticide commercial formulations and elevated temperatures (35;It was found that polymer/solvent interaction, glove thickness, and temperature play a crucial role in breakthrough time. Where the Hansen 3-dimensional solubility parameters of the glove polymer and pesticide formulation solvent were similar the breakthrough time of the active ingredient was practically instantaneous regardless of glove thickness and temperature. Degradation was the primary breakthrough mechanism.;A second mechanism, diffusion, occurred when the solubility parameters did not match, and was caused by the concentration gradients on either side of the polymeric barrier. Temperature and glove thickness were important factors in the breakthrough time. Each glove thickness exhibited a unique breakthrough time pattern and an Arrhenius type relationship. The thin glove exhibited lower breakthrough times than the thick glove for the same temperatures. The activation energy of diffusion from the Arrhenius relationship could be determined from the slope of the reciprocal breakthrough time against the reciprocal of the temperature in degrees Kelvin.;The calculated activation energy of the thick glove was less than the thin glove. This phenomenon illustrated that the glove thickness, when increased sufficiently, minimized the effect of temperature on the breakthrough time. |
