6FDA-TeMPD

The etherification reaction of polyimides is similar to the process of the imide ringopening reaction. It was demonstrated for the reaction of polyimides with primary diamine and epoxy agents [57,58] (for example, for 6FDA-TeMPD polyimides and tet-raglycidyldiaminodiphenylmethane (TGDDM), diethyltoluenedianune (DETDA) [57], TMPDA, 1,3-phenylenediamine (PDA) and4,4 -(9-fluorenylidene)dianiline (FDA) [58]). The density of polymers and crosslink concentration inaeased with the increase in epoxy content. 

The gas permeation parameters have also been reported for polymers obtained via ether reaction of epoxy and diamines [57,58], for polymer blends with acetylene-terminated oligomer [73,74] and internal acetylene polyimide [72,75]. The gas permeability of cross-linked internal acetylene-containing polymer, 6FDA-TeMPD/p-intA (4 1) declines from 612 to 186Barrer, while the selectivity, a(C02/CH4) increases from 14 to 25 at 35°C and lOatm [75]. Moreover, this cross-linked 6FDA-TeMPD/p-intA (4 1) membrane is still stable under CO2 pressure of about 47 atm. 

Figure 1.2 presents the effects of UV irradiation time on gas permeability and selectivity for acryl-terminated telechelic polyimide, 6FDA-TeMPD-BEI [33]. It is seen that the gas permeability decreases, while the selectivity increases. 

Figure 1.2 Dependence of (CO2) ( ), PiCHJ (A) and a(C02/CH4) (M) on irradiation time in UV-cross-iinked 6FDA-TeMPD-BEI membranes at 35°C. Data from Reference 133]...

In the same manner the gas permeability in hyperbranched polyimide prepared from vinyl-terminated telechelic polyimide, 6FDA-TeMPD-PAS is reduced by UV irradiation [32], The gas permeabilities of this polymer after 120min of irradiation are as follows 50Barrer for O2 and 345Barrer for CO2 at 30 °C and latm. The selectivities are 3.5 for... 

---