## 3 Results and Discussion
The most interesting conclusion is how quickly and easily the decrosslinking reaction takes place, which strongly suggests the utilization of HNPs and building blocks for recoverable and reusable networks. The chemical reaction of the crosslinking can be followed by FT-IR spectroscopy. The absorption peaks in the range of 1190 cm\({}^{-1}\) correspond to the characteristic succinimide {(CH2)2(CO)2 NH} bands that result from the formation of the DA adduct, which indicates the crosslinking reaction (Figure 7) [35; 36]. The peaks for C-O-C and Si-O-Si decrease upon crosslinking, as do the absorption bands at 616 cm\({}^{-1}\), which relate to the furan ring. New absorption peaks are observed at 1720 and 1770 cm\({}^{-1}\), corresponding to the BMI carbonyl groups [37; 38]. Kinetics Study of the Diels-Alder Reaction by UV-Vis spectroscopy  
The kinetics of the forward Diels-Alder reaction of all HNP-Fs, PSF, and PDMS-F with BMI were studied by UV-Vis spectroscopy at different temperatures (50 \({}^{\circ}\)C, 60 \({}^{\circ}\)C, and 70 \({}^{\circ}\)C). As seen in the UV-Vis spectra of the HNP-F, the maleimide absorption decreases with time at 310 nm. For HNP-Fs with BMI, the absorption at 310 nm dropped rapidly initially, indicating that maleimide groups reacted quickly (Figure 8A). After that, the absorption changed slightly only. On the other hand, the maleimide absorption of PS-MBI and PDMS-BMI decreased considerably slower than the HNP-F (Figure S4). Figure 6: **(a)** 10% (_w/w_) HNP-F and BMI dissolved in DMF and THF (1:1) before crosslinking; **(b)** crosslinked gel after heating for 2 h at 50 \({}^{\circ}\)C; **(c,d)** decrosslinking after heating at 150 \({}^{\circ}\)C for 1 min and quench cooling; **(e,f)** crosslinking again at 50 \({}^{\circ}\)C for 2 h.  
Figure 7: ATR-FTIR spectra of (a) crosslinked HNP-F with BMI (black) and (b) HNP-F (red). The degree of the reaction with the reaction time was calculated using the following expressions:  
\[\frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{k}(1-\mathrm{x})^{n} \tag{1}\]  
where x is the conversion rate, which can be expressed as  
\[x=1-\frac{A_{t}}{A_{0}} \tag{2}\]  
By rearranging Equation (2), we have  
Figure 3:0  
where \(A_{0}\) is the initial absorbance at (t = 0), and \(A_{t}\) is the absorbance at 310 nm at time \(t\). When the reaction is first-order (n = 1), Equation (1) can be written as for the pseudo-first-order reaction:  
Figure 3:1  
When the reaction is second-order (n = 2), Equation (1) can be written as  
Figure 3:2  
The reaction rate constants for the first- and second-order (\(k_{1},k_{2}\)) for the DA reaction were calculated for each temperature and are listed in Figure 3:3 The rate constants were derived from the slope of the graphs shown in (Figure 7). The reaction rate constants (\(k_{1}\), \(k_{2}\)) increased when the temperature rose from 50 \({}^{\circ}\)C to 70 \({}^{\circ}\)C. This would significantly  
Figure 3:4 (**A**) UV absorbance of BMI reaction with HNP-F with time; (**B**) first-order kinetics of HNP-F with BMI; (**C**) second-order reaction kinetics of HNP-F; and (**D**) activation energies of HNP-F, PS-F, and PDMS-F reactions with BMI. accelerate the crosslinking reaction rate because the rate constants' value significantly changes with temperature. When comparing all the results of order kinetics, the DA reaction between the polymers and BMI followed second-order kinetics [39; 40; 41]. The DA reactions' activation energy was calculated using the Arrhenius plot. Arrhenius equation:  
Figure 3:5  
\(E_{a}\) is the activation energy, \(R\) is the universal gas constant (R = 8.314 J mol\({}^{-1}\) K\({}^{-1}\)), \(T\) is the absolute temperature (K), and \(A\) is the pre-exponential factor. The DA reaction activation energy was calculated from the rate constants of the second-order reaction kinetics at 50 \({}^{\circ}\)C, 60 \({}^{\circ}\)C, and 70 \({}^{\circ}\)C, which was determined by the slope of the line from graphing \(\ln k\) versus 1/T, shown in Figure 8D.