Synthesis and gas permeability of poly( p -phenyleneethynylene)s having bulky alkoxy or alkyl groups

Dipropynylbenzene with branched alkoxy and alkyl groups [CH3C≡CRC6H2RC≡CCH3, R = 2-methylpropoxy (1a), 3-methylbutoxy (1b), 4-methylpentoxy (1c), cyclohexylmethoxy (1d), 2-ethylhexoxy (1e), 2-octoxy (1f), 2-ethylhexyl (1g), and 2-octyl (1h)] were polymerized with Mo(CO)6 in the presence of 4-(trifluoromethyl)phenyl to afford poly(2,5-di(alkoxy or alkyl)-p-phenyleneethynylene)s (2a–h). Polymer 2a was insoluble in any solvents, but the other polymers (2b–h) were soluble in common organic solvents. The polymers with relatively long side chains (2e–h) had high molecular weight over 1.6 × 104 and gave free-standing membranes by solution-casting method. The densities of membranes of 2e–h were 0.914–0.998, and their fractional-free volume values were relatively large (0.094–0.158). The oxygen permeability coefficients of membranes of 2e–h were 18.4, 12.7, 4.85, and 19.3 barrers, respectively. It was found that poly(p-phenyleneethynylene) with 2-octyl side groups, which have the branch at the nearest position from main chain, exhibited the highest gas permeability.

...We reported that poly(2,5-dialkoxy-p-phenyleneethynylene)s (PPEs) exhibited relatively high gas permeability [13] which indicates a possibility of PPEs for a material of gas-separation membrane...
...respectively, which are much larger than those of poly(p-phenyleneethynylene)s with alkyl side groups; e.g., the densities of poly(2,5-dihexyl-p-phenyleneethynylene), poly(2,5-didecyl-p-phenyleneethynylene), and poly[2,5-di(2-octyl)-p-phenyleneethynylene] are 0.965, 0.936, and 0.914 g/cm 3 , respectively [13, 25]...
...They are much smaller than those of the alkyl-substituted poly(p-phenyleneethynylene)s (FFV = 0.140–0.158) [13, 25]...
...The gas permeability of membranes of 2b and 2c to nitrogen, oxygen, and carbon dioxide was examined at 25 C (Table 3). The nitrogen permeability coefficients (PN2) of membranes of 2b and 2c were 0.38 and 0.27 barrers, respectively, whose values are one magnitude smaller than PPEs with alkyl or alkoxy groups [13, 25]...
...The data of poly (p-phenyleneethynylene)s having alkyl or alkoxy groups [13, 25] are also plotted in Fig. 3. It is clearly observed from Fig. 3 that the PPEs in this study (2b, 2c) exhibited much higher CO2 permselectivity than the PPEs possessing alkyl and alkoxy groups...

Keywords (3)

Synthesis and gas permeability of poly( p -phenyleneethynylene)s having bulky alkoxy or alkyl groups,10.1007/s00289-010-0342-6,Polymer Bulletin,Toshik

Citation Context (1)

Toshikazu SakaguchiKota Sanada, et al. Synthesis of poly( p -phenyleneethynylene)s bearing oligo-ethylene gly...

References (17)

Membranes for gas separation (Citations: 73)

Poly[1-(trimethylsilyl)-1-propyne] and related polymers: synthesis, properties and functions (Citations: 76)

Future Directions of Membrane Gas Separation Technology (Citations: 160)

Alkyne Metathesis with Simple Catalyst Systems: Poly( p -phenyleneethynylene)s (Citations: 15)

Synthesis of α,ω-Difunctionalized Oligo- and Poly( p - phenyleneethynylene)s (Citations: 18)

Citations (1)

Synthesis of poly( p -phenyleneethynylene)s bearing oligo-ethylene glycols and their gas permeation properties


	The following links allow you to view full publications. These links are maintained by other sources not affiliated with Microsoft Academic Search.


	BibTex \| RIS \| RefWorks Download