The Differential Scanning Calorimetry (DSC) trace for a commercial phenolic resole resin shows two distinct peaks. Assuming that these represent two independent cure reactions results in a kinetic model of the form: with κi = κio exp(‐Bi/T). The Arrhenius parameters were estimated from a plot of ln(β/T italicp2) versus 1/Tp. The parameters, p, n1, and n2 were obtained by writing the DSC response predicted by the equation above in terms of a function which contains temperature as the only variable. with \documentclass{article}\pagestyle{empty}\begin{document}$ \theta _i = \left({1/\beta} \right)\int_{T_0}^T {\kappa _i dT \le r_i} $\end{document} dT ⩽ ri and ri = 1/(1‐ni). Fitting this equation to the DSC response measured at a scan rate of 4°C/min obtains p ≈ 0.66; n1 ≈ 0.55; n2 ≈ 2.2; B1 ≈ 8285; B2 ≈ 7480; κ1 ≈ 1. 12 × 108 s−1; κ2 ≈ 0.99 × 106 S−1.

ABSTRACT:This study evaluates the use of a simple mathematical model to predict release characteristics of volatile substances from polymer dispensers. The model can be used to simplify the design process of polymer dispensers, which is traditionally done by trial and error. The coefficients of diffusion, D, of four alcohols through EVA disks were determined with the time lag technique. The value of D was used to predict the residual mass of dispensers over time using a model based on Fick's second law of diffusion. Injection-molded dispensers containing 10% alcohol were prepared, and the release of the alcohol were monitored experimentally. The modeled results were compared to the experimental results. A good correlation was found between the predictions and the experimental results.

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