Polymerization of silicon-containing diphenylacetylenes and high gas permeability of the product polymers

Abstract

Poly(diphenylacety1ene) is thermally very stable, but insoluble in any solvent, whereas polyacetylenes from unsymmetrically disubstituted acetylenes are generally soluble. Hence, the synthesis of soluble poly(diphenylacety1enes) was examined by introducing the trimethylsilyl group. 1-Phenyl-2-lp-(trimethylaily1)phenyllacetylene and l-phenyl-2-[m-(trimethylsilyl)phenyl]acetylene polymerized with T a c k cocatalyst systems to provide new polymers with over 70% yields having a weight-average molecular weight over 1 X 106. As cocatalysts, nBurSn, EhSiH, and SBBN were especially effective. The polymers were yellow solids with the alternating double bond structure [-CP~=C(C&S~M~S)-I,,. They completely dissolved in toluene, CHCla, etc., and formed tough f i i by eolution casting. The onset temperatures of weight loss in TGA in air were as high as ca. 400 "C. Their oxygen permeability coefficients were both high, ca. lo00 barrers.

Polymerization of Substituted Acetylenes by the Grubbs–Hoveyda Ru Carbene Complex

“…35,38 Whereas the Ta-, Mo-, and W-based polymers had colors of yellow to orange-yellow, only the Ru-based samples was virtually white in the powdery state. For the sake of comparison, poly(DPA) (DPA: diphenylacetylene) samples were also prepared, as is listed in Table V.…”

Polymerization of diphenylacetylenes having very bulky silyl groups and polymer properties

“…A detailed procedure of polymerization has been described elsewhere. 4 Polymers were isolated by precipitation into a large amount of methanol, and polymer yields were determined by gravimetry.…”

“…1 Among the acetylenic monomers, 1-(trimethylsilyl)-1-propyne (TMSP) 2 and 1-phenyl-2-[p-(trimethylsilyl)phenyl]acetylene (pMe 3 SiDPA) 3,4 polymerize with TaCl 5 alone or its mixture with organometallic cocatalysts to provide high molecular weight polymers (M w Ͼ 1 ϫ 10 6 ) in quantitative yield. Both of these Si-containing polymers show high gas permeability, and their gas permeation behavior has recently been under intensive research.…”

“…Further, poly(pMe 3 SiDPA) is thermally fairly stable, as is seen from its onset temperature of the weight loss in air (T 0 ) as high as 430°C. 3,4 Hence, it is of interest to study the polymerization behavior and polymer properties of diphenylacetylenes that have substituents bulkier than the trimethylsilyl group. In the present study, we investigated the polymerization of 1-phenyl-2-[4-(triphenylsilyl)phenyl]acetylene (pPh 3 SiDPA) and 1-phenyl-2-[4-(triisopropylsilyl)phenyl]acetylene (piPr 3 SiDPA), both of which possess very bulky silyl groups.…”

Synthesis and Properties of Substituted Polyacetylenes Having Cyclohexyl Groups

“…For instance, poly[1-(trimethylsilyl)-1-propyne] [poly(TMSP)] displays the highest gas permeability among all the existing polymers. 9,10 Poly-[1-phenyl-2-(p-trimethylsilyl)phenylacetylene] [poly-(TMSDPA)] exhibits both high gas permeability and thermal stability; its oxygen permeability coefficient (P O 2 ) is as large as 1100 barrers, and the onset temperature of weight loss is 420 C. 11,12 Recently, the study of gas permeability and permselectivity of polymeric membranes has become a subject of substantial interest in both industrial and academic laboratories. The main motivation for these studies is primarily an empirical search for improved materials as gas separation membranes.…”