Polymerization of [o‐(trimethylgermyl)phenyl] acetylene and polymer characterization

Abstract

[o‐(Trimethylgermyl)phenyl]acetylene was polymerized in the presence of WCl6, W(CO)6‐hv, etc., to give polymers whose weight‐average molecular weights reached ca. 7.0 X 105 at the highest. When the MoOCl4‐n‐Bu4Sn‐EtOH (1 : 1 : 1) catalyst was used, the polydispersity ratio of the polymer obtained was 1.08, and the number‐average molecular weight increased in direct proportion to monomer conversion; these indicate that this polymerization is a living polymerization. The polymer had the structure  [CHC(C6H4‐o‐GeMe3)]n  and was a dark purple solid (λmax = 551 nm, εmax = 6100 M‐1 cm‐1 in THF) soluble in organic solvents such as toluene and chloroform. The onset temperature of weight loss of the polymer in TGA in air was ca. 230°C, and the glass transition temperature was above 180°C. The Po2 of the present polymer is 105 barrers—larger than the value of natural rubber and fairly close to that of poly(dimethylsiloxane). © 1993 John Wiley & Sons, Inc.

Preparation and characterization of polyvinyl acetate/zeolite 4A mixed matrix membrane for gas separation

“…This upper bound which is showing a tradeoff between permeability and selectivity represents the biggest challenge for improved separation performance, and limit their application in industry [8,12]. From 1990 to 2008 different researchers have focused their efforts on tailoring polymer structures for membrane materials and obtained better separation of O 2 /N 2 [13,14], CO 2 /N 2 [15,16] and H 2 /N 2 [17,18]. Inspite of the improvement in gas separation properties it has only slightly shifted the upper bound as shown by Robeson in his revised upper bound in 2008 [19].…”

Synthesis, structure, and properties of poly[1‐(trimethylgermyl)‐1‐propyne]

“…Several Ge-containing polyacetylenes have been synthesized thus far, and it has been revealed that some of them also show high gas permeability. For example, the oxygen permeability coefficients (P O 2 ) of poly[o-(trimethylgermyl)phenylacetylene] 5 and poly[1-phenyl-2-[m-(trimethylgermyl)phenylacetylene] 6 are 110 and 1100 barrer, respectively. Further, a patent 7 has disclosed that 1-(trimethylgermyl)-1-propyne (TMGP) polymerizes with TaCl 5 to produce a polymer that is insoluble in any solvent except carbon disulfide and whose P O 2 value is higher than 4000 barrer.…”

SEC/DAD and1H NMR Study of Molecular Weight and Configurational Stability of Poly(2,4-difluorophenylacetylene) and Polyphenylacetylene Prepared with Rh Catalyst

“…[62,75,81,87] The stability enhancement was reported to be especially significant if PPhA was substituted in the ortho position, i.e., in the vicinity to the polymer main chain. [81,87] The above discussion on the interconnection of cis-to-trans isomerization and degradation of PdFPhA and PPhA lead to the conclusion that the degradation proceeded (predominantly) as a consecutive process to cis-to-trans isomerization. Thus, the decrease in the rate of cis-to-trans isomerization of PdFPhA (compared to PPhA, Figure 7) evidently positively affects also the MW stability of PdFPhA.…”