2.2. Synthesis of ODPA-TMPDA Polymer

The synthesis of ODPA-TMPDA polymer can be summarized by the reaction scheme in Figure 1 [23,24,25]. First, 20.0 g of DMAc was poured into a round-bottom flask, following which 1.63 g of TMPDA was added. During this process, sufficient agitation time was allocated to assure complete dissolution of TMPDA. This was followed by the addition of 3.36 g of ODPA to the solution. Vigorous stirring for at least 24 h was performed to create polyamic acid with 20 wt % concentration. Subsequently, imidization process was performed via the addition of 4.44 g of Ac₂O and 4.39 g of TEA. Agitation for at least 24 h was conducted, followed by reprecipitation in ethanol solution. The unreacted substituents potentially present in the polymer were removed by washing with copious amount of ethanol. Finally, the polymer was dried in a vacuum oven at 120 °C. The structural properties of the as-synthesized ODPA-TMPDA polymer were characterized by Fourier Transform-Infrared Spectroscopy (FT-IR, Shimadzu, Kyoto, Japan) under ambient condition. The measurement was conducted in the wavenumber that ranged from 450–4000 cm⁻¹ at the resolution of 4 cm⁻¹.

Reaction scheme for the synthesis of ODPA-TMPDA polymer.