ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
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: \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{dx}}{{dt}} = p\kappa _1 \left({1 - x_1} \right)^{n_1} + \left({1 - p} \right)\kappa _2 \left({1 - x_2} \right)^{n_2} $$\end{document} with κi = κio exp(-Bi/T).The Arrhenius parameters were estimated from a plot of ln(β/Tp2) 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. \documentclass{article}\pagestyle{empty}\begin{document}$$ \dot q = q_{tot} \left[{p\kappa _1 \left({1 - \theta _1 /r_1} \right)^{r_1 - 1} + \left({1 - p} \right)\kappa _2 \left({1 - \theta _2 /2} \right)^{r_2 - 1}} \right] $$\end{document} 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.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760312306
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