Figure 3. The thermal properties of acrylic acid derivative terpolymer. (a) The thermal gravimetric (TG) curves of LA136D, PVDF, and SBR, the proportions of volatiles generated in the three binders thermal decomposition are 39.2wt %, 77.6wt % and 99.2wt % respectively; (b) the differential coefficient of the TG curves in (a), it is shown LA136D has the lowest volatiles generation rate in the thermal decomposition; (c) the Fourier-transform infrared spectroscopy (FTIR) results of LA136D before and after 550 °C treatment, it is shown there are some C−N and C−O groups in the solid residues, which indicates C≡N and C=O are beneficial to reach a low volatile proportion in thermal decomposition; (d) the in-situ analysis of the gaseous fragments produced in LA136D thermal decomposition by using TG-FTIR; (e) The proposed thermal decomposition process of LA136D at the high temperatures.
To further study the thermal decomposition process of LA136D, we studied the gas products of LA136D by TG-FTIR. The result is shown inFigure 3 (d) . It is shown that few NH3 occur at about 230 °C and spurts out after 300 °C, indicating the breaking of C−H (possibly the ends of the main chain) and C−NH2. At the same time, the CO2 generates at nearly 300 °C, indicates the breaking of R−COOLi (the occurrence of CO2 before 300 °C is due to the background of TG-FTIR). The CH4 and other C−H volatiles occur after 400°C, referring to the break of the −C−C− chain, this can also be verified by the differential curve of LA136D in Figure 3 (b) whereas the rate of thermal decomposition reaches peak value. Based on the discussions above, the thermal decomposition process and the gas products of LA136D can be described inFigure 3 (e) . When heating the LA136D, RCO−NH2,and R−COOLi begin to break at nearly 230 °C and 300 °C accompanying the generation of NH3 and CO2 gaseous respectively. The RCO−NH2 breaking rate reaches a peak value at 320 °C. As the temperature keeps increasing to 400 °C, the main chain −C−C− begins to break and CH4 or other C−H gaseous fragments are produced. The break of R−COOLi goes with the whole heating process.