Hydrodynamic and Molecular Study of Poly{4‐[4‐(hexyloxy)phenyl]ethynylphenyl methacrylate} in Dilute Solutions and Conformational Peculiarities of Brush‐Like Macromolecules

Abstract

Brush-like poly{4-[4-(hexyloxy)phenyl]ethynylphenyl methacrylate}s are synthesized using RAFT polymerization, fractionated and studied by molecular hydrodynamic methods. The values of the velocity sedimentation coeffi cient, the frictional ratio, and the intrinsic viscosity are obtained in toluene. The conformational and structural parameters of the studied poly mer chains are estimated by the use of theories that describe the hydrodynamic behavior of the wormlike cylinders without intra-chain excluded volume effects and the hydrodynamic behavior of bending rods. The intrinsic viscosity data obtained for poly{4-[4-(hexyloxy)phenyl]ethynylphenyl methacrylate}s and for other brush-like macromolecules are discussed in terms of a doubly-normalized scaling plot. erties of a common polymer, poly{4-[4-(hexyloxy)phenyl] ethynylphenyl methacrylate}s (PHPhEPhMs) were synthesized. The aim of this work is the investigation of the hydrodynamic, molecular and conformational characteristics of a PHPhEPhM homologous series in toluene solutions and the comparison to the hydrodynamic data obtained for various brush-like polymers on the base of the concept of normalized scaling relations. In the Supporting Information to this article, the graphic materials for handling the initial experimental data are summarized. Experimental Section Materials and MethodsAll chemicals used were purchased from Biosolve, Fluka, Aldrich, Acros Organics, as well as Alfa Aesar and were used without further purifi cation unless otherwise specifi ed. The solvents were purchased from Biosolve, Aldrich, or Acros Organics and were dried and distilled according to standard procedures. The synthesis of the monomer 4-[4-(hexyloxy)phenyl]ethynylphenyl methacrylate is described elsewhere. [ 48 ] Macromol. Chem. Phys. 2012, 213, 904−916

Living Radical Polymerization by the RAFT Process – A Third Update

“…It has been reported that the extent of branching is higher 289 [186,187,229,577] 290 [175,203,305] 291 [211] 295 [308] 301 [165] 306 CSSQMA [389] 302 [164] 303 [209] 304 [305] 307 [578,579] 308 [579] 305 [212] 297 [188] 298 [201] 299 [201] 300 [387] 292 [189] 293 [173] 294 [210] Glycerol monomethacrylate Solketal methacrylate 296 [197,390] for conventional radical polymerization than for RDRP (ATRP, RAFT, and NMP). [443] A qualitative explanation was proposed in terms of the differences in the concentrations of short-chain radicals between RDRP and conventional radical polymerization.…”

Synthesis and characterization of polymethacrylates containing conjugated oligo(phenylene ethynylene)s as side chains

“…This is supposed to be a result of the dense comb-like structure of the polymers that hinders the formation of loose polymer coils (e.g., as in the case of PS) in solution. 14 In contrast to the homopolymers P1-P3 and P2-stat-P3, the PMMA-containing copolymer's molar masses were determined only by SEC ( Table 1). The accordance between the theoretical molar masses and the measured ones leads to the conclusion that SEC provides reliable values.…”

“…[11][12][13] The dense packing of the side chains covalently bound to a linear backbone causes confined and compact structures, in particular, worm-like conformations. 14 Hence, notable chain end effects can be observed. The incorporation/attachment of conjugated oligomers to nonconjugated backbones leads to a variety of different structures due to the wide range of possible pendant molecules revealing chemical stability, photoconductivity of the attached p-electron systems, and an invariance of the standard oxidation/reduction potential with the degree of substitution.…”

Thermally triggered optical tuning of π-conjugated graft copolymers based on reversible Diels–Alder reaction

“…7,8 In gra polymers, side chains offer the possibility of dense packing, resulting in compact and conned structures. 9 In order to combine the well-dened optoelectronic properties of monodisperse oligomer moieties and typical polymer properties, e.g., mechanical and chemical stability as well as processability into thin lms, conjugated side chains have been attached to aliphatic polymers. Several p-conjugated oligomers have been successfully implemented as side chains, for instance triphenylamines, [10][11][12][13] oligothiophenes, 14 carbazoles, 15 perylenes, 16 phenylene ethynylenes 17 and diphenyl acetylenes.…”