Hyperbranched polyimides selectivity

Recently, hyperbranched polyimides were obtained by selective orderly reaction only at polymer ends using telechelic polyimides with terminal reactive groups of acetylene, vinyl and acryl [29-33],... 

Almost all hyperbranched polyimides with reported gas permeation parameters were synthesized from A2- and Bs-type monomers. The corresponding transport data are presented in Table 1.4 [20-26]. All the polymers are in a glassy state. The gas permeabilities of hyperbranched polyimides vary from 0.02 to 11 Barrer for O2 and from 0.08 to 65 Barrer for CO2 at 20-35 °C. The selectivities vary from 2.0 to 13 for a(02/N2) and from 3.4 to 70.1 for a(C02/N2). 

Table 1.4 Cas permeability coefficients (Barter) and selectivity of hyperbranched polyimides (Type III)... 

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... 

Ekinci E, Emre FB, Koytepe S, Segkin T (2005) Preparation, characterization and H2O2 selectivity of hyperbranched polyimides, containing triazine. J.Polym. Res. 12 205-210. 

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