Interactions in liquid-crystal side-chain polymer solutions—1. Evidence for mesophase formation in solution

Woliński, Leszek; Witkowski, Konrad; Turzyński, Zbigniew

doi:10.1016/0014-3057(90)90202-f

Cited by 4 publications

(5 citation statements)

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“…Many of these SCLCPs aggregate in organic solvents, − evidently due to strong mesogen−mesogen interactions. The formation of an excimer by poly[3-(4‘-cyanophenyl-4‘ ‘-phenoxy)propyl acrylate] in THF at dilute concentrations, but not by 3-(4‘-cyanophenyl-4‘ ‘-phenoxy)pentane, indicates that (intramolecular) mesogen−mesogen interactions are stronger in SCLCPs than in the corresponding low molar mass liquid crystals .…”

Section: Introductionmentioning

confidence: 99%

“…The formation of an excimer by poly[3-(4‘-cyanophenyl-4‘ ‘-phenoxy)propyl acrylate] in THF at dilute concentrations, but not by 3-(4‘-cyanophenyl-4‘ ‘-phenoxy)pentane, indicates that (intramolecular) mesogen−mesogen interactions are stronger in SCLCPs than in the corresponding low molar mass liquid crystals . Although the strength of the intramolecular mesogen−mesogen interactions apparently decreases with increasing spacer length, the ability to associate via intermolecular mesogen−mesogen interactions increases with increasing spacer length. , …”

Section: Introductionmentioning

confidence: 99%

“…There are relatively few studies on the absolute molecular weights and solution behavior of SCLCPs, all of which were prepared by conventional radical polymerizations, in organic solvents. [5][6][7][8][9][10][11][12] Homopolymers and random copolymers of (4′-methoxyphenyl-4′′-phenoxy)oligooxyethylene methacrylates with different spacer lengths (zero to four oxyethylene units) were characterized by GPC in THF using a light scattering detector at 90°. 6 The absolute molecular weights were significantly higher than the GPC PSt -determined molecular weights, which demonstrates that the hydrodynamic volumes of the SCLCPs and copolymers are smaller than that of linear polystyrene.…”

Section: Introductionmentioning

confidence: 99%

“…13 Although the strength of the intramolecular mesogen-mesogen interactions apparently decreases with increasing spacer length, 13 the ability to associate via intermolecular mesogen-mesogen interactions increases with increasing spacer length. 9,12 There are far more studies on the solution properties of common polymers with different topologies. 14 In general, branched polymers are more compact than the corresponding linear polymers at the same molecular weight.…”

Section: Introductionmentioning

confidence: 99%

“…previous[5][6][7][8][9][10][11][12] solution studies of SCLCPs. Aggregation is even more prominent in the light scattering chromatograms of the linear polymer in THF ( ) 7.52 at 20 °C) and CHCl 3 ( ) 4.81 at 20 °C), which are less polar solvents than CH 2 Cl 2 ( ) 8.93 at 20 °C).…”

mentioning

confidence: 99%

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Solution Behavior of Topological Isomers of Poly[11-(4‘-cyanophenyl-4‘ ‘-phenoxy)undecyl acrylate]s Prepared by Atom Transfer and Conventional Radical Polymerizations

Kasko

Pugh

2004

Macromolecules

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The solution behavior of linear, three-arm star, and comb poly[11-(4‘-cyanophenyl-4‘ ‘-phenoxy)undecyl acrylate]s previously synthesized by atom transfer radical polymerization was investigated by gel permeation chromatography (GPCPSt) and light scattering measurements in CH2Cl2, THF, and CHCl3 in order to correlate their size and shape with their molecular architecture and in order to investigate the extent of branching in the corresponding polymer prepared by conventional radical polymerization. The inaccuracy of the GPCPSt molecular weights increases as the polymers become more branched: linear < three-arm star < comb; the discrepancy between the GPCPSt and absolute molecular weights of polymers fractionated from the conventional radical polymerization is between those of the three-arm star and comb polymers in all three solvents. Light scattering studies demonstrate that CH2Cl2 is the best solvent for all of the polymers, resulting in either no aggregation or an insignificant amount of aggregation, whereas all of the topologies except the comb polymers tend to aggregate in THF and CHCl3; nevertheless, the extent of aggregation is not great enough to be detected by variations in the average GPCLS-determined molecular weights measured in any of these solvents. The tendency to aggregate in all of the solvents and the radius of gyration in CH2Cl2 decrease as the branching increases: linear > three-arm star > comb, with the polymer prepared by conventional radical polymerization being similar to the branched polymers. The scaling coefficients (R g = KM ν) of all of the polymers are similar in CH2Cl2, with ν = 0.37 for the three-arm star polymers, ν = 0.39 for the comb polymers, and ν = 0.32 for the polymer prepared by conventional radical polymerization. The relative values of the contraction factors, g = 〈R g 2〉br/〈R g 2〉lin, decrease in the order g star > g comb > g radical for the three-arm star polymers, the comb polymers, and the polymer prepared by conventional radical polymerization, respectively, in CH2Cl2.

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