Table 1 Characterization of PAIs.
Polymer codeu/(u + s)*ηinh
(dl g−1)
λco (nm)T550 (%)§Td5 (°C)CTE (ppm/°C)
In N2In airSecond runThird run
PAI(s-s)0.003.76371884574328.79.5
PAI(s-su)0.253.90371884684746.17.4
PAI(su-s)0.252.90364884974795.65.2
PAI(s-u)0.503.98371884784844.24.4
PAI(u-s)0.503.02371894854864.65.7
PAI(su-su)0.503.40371884824924.84.8
PAI(su-u)0.753.62371885114965.66.1
PAI(u-u)1.003.50371884654767.57.6

*Molar fraction of uDA-originated repeating units in the total diamine content.

†Inherent viscosity measured in NMP at 0.5 g dl−1 concentration at 30°C.

‡Cutoff wavelength determined by UV-vis spectra of freestanding polymer films 70 to 80 μm thick.

§Transmittance at 550 nm.

║5% weight loss temperature measured by TGA at a heating rate of 10°C/min.

¶Calculated from the mean coefficient of linear thermal expansion between 50° and 250°C in the second and third heating runs, respectively.