## 8 Discussion  
The results have shown that the kinetic triplet describing the curing of a polymer can be obtained by straightforward experimental DSC measurements. The parameters for the kinetic triplet of the polyurethane polymer studied are summarized in Table 4.  
This set of parameters describes all measured data equally well. The parameters are used as input to finite element analysis for predicting curing of cast components. The procedure described here allowed finding a consistent set of parameters. The activation energy \(E_{\alpha}\) was obtained based on the isoconversional method, the Arrhenius pre-factor \(A_{\alpha}\) was determined using the compensation effect and the kinetic function \(f(\alpha)\) was obtained by comparing the actual kinetic function calculated with the correct activation energy and pre-factor with known kinetic models for polymers. Regular curve fitting was than used to determine the parameter \(P\) and \(n\) of said kinetic function. The equations to obtain the parameters are simple as shown in the previous sections. However, performing all the required calculations against experimental data is substantial and can be considered as not trivial. Computer programs need to be created to make the data analysis possible. However, this is a rather simple task and commercial software exists for free, and open source programs can be found online in the common software repositories. Simplifications were made either to analyze the data and for the final finite element simulations. * A straight heat flow baseline was assumed. The baseline corrected heat flow data was obtained by simply subtracting the post-cure run data from the cure-run heat flow data. * Mean values were used for the total heat \(Q_{\text{total}}\), the compensation parameters \(a\) and \(b\), and the parameters \(P\) and \(n\) of the kinetic function, as stated above. * A \(n\)-th order kinetic function was used for \(f(\alpha)\), which is one of the simplest models to describe the curing of a polymer. * The first ca. 6% of the calculated actual kinetic function were omitted to arrive at said conclusion that the reaction can be described with a \(n\)-th order kinetic model. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Symbol** & **Value** \\ \hline total heat of reaction & \(Q_{\text{total}}\) & \(67/\text{g}\) \\ activation energy for \(\alpha\leq 50\%\) & \(E_{\alpha}\) & \([42+17\alpha-28a^{2}]\) kJ/mol \\ activation energy for \(\alpha>50\%\) & \(E_{\alpha}\) & \(44\) kJ/mol \\ Arrhenius pre-factor & \(A_{\alpha}\) & \(a+b\cdot E_{\alpha}\) \\ compensation factor & \(a\) & \(-2.6\)/mol \\ compensation factor & \(b\) & \(3.3\times 10^{-4}\) \\ kinetic function & \(f(\alpha)\) & \(P\cdot(1-\alpha)^{n}\) \\ “power factor” & \(p\) & \(3.275\) \\ reaction order & \(n\) & \(2.023\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of the determined values, with \(\alpha\) as the conversion. The choice of these simplifications is mainly justified by the success of modeling the generated heat and temperature of the DSC experiments and of a cast big block. The predicted temperature and heat of the DSC tests match the measured values well, regardless of if a slow isothermal reaction at 293 K or a fast dynamic experiment with a heating rate of 10 K/min are predicted. The former needs many hours and exhibits rather small heat flow values while the latter reaches 100% conversion in a matter of minutes and develops heat flow values more than a magnitude larger. The simulation of a large cast of said material predicted the location dependent magnitude and the trend of the temperature within an accuracy of 3 K. Thus, despite the simplifications the above-described methods give relatively precise predictions. Since the analysis based on the isoconversion method is an integral method, the influence of the natural variations between experiments is minor and the determined model is good enough for engineering purposes.