New High Permeable Addition Poly(tricyclononenes) with Si(CH3)3 Side Groups. Synthesis, Gas Permeation Parameters, and Free Volume

Addition polymerization of two tricyclononene monomers bearing one and two Si(CH3)3 groups was performed in the presence of Pd-containing catalysts. The polymers were obtained with high yields and were completely saturated. Good mechanical and film forming properties are observed for the polymers prepared in the presence of Pd(OAc)2/B(C6F5)3 catalyst. Their glass transition temperature was not observed until the onset of thermal decomposition (>370 °C) and the molecular weights are high (Mw up to 7 × 105). Study of gas permeation parameters of the obtained poly[3-(trimethylsilyl)tricyclononene-7] and poly[3,4- bis(trimethylsilyl)tricyclononene-7] showed that both glassy polymers revealed substantially high gas permeability. Other transport characteristics (increase in permeability in the series C1−C4 alkanes and negative activation energies of permeation) indicate that these polymers reveal so-called solubility controlled permeation, which is typical for some extra-high permeability polymers. Positron ann...