Complex dynamics of hydrogen bonded self-assembling polymers

Wübbenhorst, Michael; Turnhout, J. van; Folmer, B. J. B.; Sijbesma, Rint P.; Meijer, E. W.

doi:10.1109/94.933345

Cited by 55 publications

(39 citation statements)

References 23 publications

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“…Hydrogen bonding moieties are widely used for designing supramolecular polymers, since they demonstrate very broad range of strength, which can be controlled by the number and the configuration of the interactions . One of these promising moieties is ureidopyrimidinone (UPy) group, which self‐assembles with high‐strength, quadruple hydrogen bonds . Low molar mass telechelic polymers that are viscous liquid at room temperature show properties like solid polymers after functionalization with UPy groups .…”

Section: Introductionmentioning

confidence: 99%

Dynamics of entangled supramolecular polymer networks in presence of high‐order associations of strong hydrogen bonding groups

Jangizehi

Ghaffarian

Ahmadi

2017

Polymers for Advanced Techs

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Dynamics of entangled polymer chains in the melt state are deliberately excluded in most of the studies on supramolecular polymer networks by utilizing nonentangled precursor chains. Relaxation of the system mainly depends on the dissociation of the associative groups in latter case and nonentangled chains deliver nothing to resist afterward. Conversely, in an entangled system, relaxation of polymer chains and dissociation of associative groups can occurred parallel.Supramolecular networks based on an entangled precursor polymer with different levels of strong associating ureidopyrimidinone (UPy) groups are synthesized to screen the corresponding effects on the dynamics of the system. Binary-associated UPy groups phase separate into collective assemblies by stacking and form high-order, needle-like domains at higher UPy contents. Relaxation of polymer chains is significantly hindered due to the trapping of polymer segments between UPy stacks. Above a certain threshold of UPy content (~4 mol%), the plateau level and final relaxation time of networks show a significant jump, which is attributed to the onset of high-order association of UPy groups. KEYWORDS chain dynamics, high-order associations, supramolecular networks 1 | INTRODUCTION Supramolecular polymer networks are macromolecular structures in which a fraction of covalent bonds are replaced with transient associations, 1-6 such as ionic attractions, 7-11 metal-ligand coordinations, [12][13][14][15][16][17] hydrogen bondings, 18-21 or π-π interactions. 22,23 Such transient bonds are in the dynamic equilibrium between associated and dissociated states. Consequently, supramolecular polymer networks response to the external stimuli and have potential to use for designing electronic, 24,25 optic-electronic, 26,27 drug-delivery, 28-32 and/or selfhealing 17,33-40 materials. The supramolecular polymer networks are divided in 2 general types. In the first type, the polymeric building blocks have associative groups at both extremities, and the virtual molar mass is increased by chain extension due to the self-assembly of end groups.In the second type, the linear or branched polymer chains carry pendant associative "sticky" groups. 41 Hydrogen bonding moieties are widely used for designing supramolecular polymers, since they demonstrate very broad range of strength, which can be controlled by the number and the configuration of the interactions. 42,43 One of these promising moieties is ureidopyrimidinone (UPy) group, which self-assembles with highstrength, quadruple hydrogen bonds. [44][45][46][47][48][49][50] Low molar mass telechelic polymers that are viscous liquid at room temperature show properties like solid polymers after functionalization with UPy groups. [51][52][53][54][55][56][57] Binary-associated UPy moieties create π-π stacking when the UPy motifs are linked to the building block chains by urethane or urea groups, which can form lateral-secondary interactions. 56,[58][59][60] The formation of micrometer long fibers in the morphology of UPy-functionalized...

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Section: Introductionmentioning

confidence: 99%

Dynamics of entangled supramolecular polymer networks in presence of high‐order associations of strong hydrogen bonding groups

Jangizehi

Ghaffarian

Ahmadi

2017

Polymers for Advanced Techs

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“…9 A prerequisite for the application of dielectric relaxation spectroscopy is the presence of dipoles, which provide the necessary link between the molecular motions and the interactions with an external electrical (probing) field. Though most of the polymer systems contain at least weakly polar groups, in either the main chain or the side chain, there is a substantial class of nonpolar polymers like polyolefins, which do not have dipoles.…”

Section: Introductionmentioning

confidence: 99%

Dielectric and Fluorescent Probes To Investigate Glass Transition, Melt, and Crystallization in Polyolefins

et al. 2004

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Investigation of glass transition dynamics in polyolefins by broadband dielectric spectroscopy (DRS) is facilitated by the addition of a novel dielectric probe, (4,4′-(N,N-dibutylamino)-(E)-nitrostilbene (DBANS), which introduces dipoles and made the polymers dielectrically active. For probe concentrations between 0.1% and 1.0% the dielectric strength ∆ associated with the dynamic glass transition increases proportionally to the probe concentration. This result indicates that the probe exhibits no intramolecular relaxations, and the probe rotational diffusion effectively senses the "microviscosity" of the probe environment on the length scale of the segmental dynamics. Temperature-dependent fluorescence spectroscopy on doped polymers shows no changes in fluorescence wavelength around the glass transition temperature. Crystallization and melting of the polyolefin matrix results in an increase or decrease of the probe concentration in the amorphous phase, which was clearly detected by real-time fluorescence because the probe emission is sensitive to the probe content, particularly at higher probe concentrations.

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“…Typical examples of polymers studied by DRS include traditional amorphous (PMMA, PC) and semi-crystalline polymers (PET, PEN, PEO) [2,5,6], complex, (multi-phase) liquid-crystalline polymers [7,8] as well as nano-composites or supra-molecular polymers [9]. A prerequisite for the application of dielectric relaxation spectroscopy is the presence of molecular dipoles, which provide the necessary link between the molecular motions and an external electrical (probing) field.…”

Section: Introductionmentioning

confidence: 99%

Characteristic size of molecular dynamics in polymers probed by dielectric probes of variable length

Berg

Wübbenhorst

Picken

et al. 2005

Journal of Non-Crystalline Solids

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Recently we introduced a rigid-rod type chromophore, E-4,4 0 -N,N-dibutylamino-nitro-stilbene (DBANS), that acts as a dielectric and fluorescent probe, and enables the study of molecular dynamics in apolar polymers by dielectric relaxation spectroscopy (DRS). This work focuses on the effect of the probe size and concentration on the specific probe response. For this purpose, a series of probe molecules with core lengths (l) between 0.6 and 2 nm was used to ÔdopeÕ polystyrene at concentrations from 0.1 to 1.0 wt%. For all probes, a selective amplification of the intrinsic a-relaxation was found that was linear within the whole probe concentration range. Moreover, two clear size effects on the probe dynamics were revealed. At high temperatures, the probe relaxation time obeys s / l 3 , which confirmed rotational diffusion as the linking mechanism between the polymeric segmental dynamics and dielectric probe response. The shortest probe revealed an additional Arrhenius-type (b * ) relaxation that was attributed to large angular probe fluctuations involving discrete jumps. Its exclusive occurrence indicates a critical lower probe size (l * $ 0.6 nm) below which the dielectric probe acts also as a Ôfree-volume probeÕ as indicated by the pronounced anormality in the s b Ã ðT Þ dependence. Finally, an attempt was made to relate probe concentration effects on the glass transition temperature (plasticizing effect) to the intrinsic length scale of cooperative dynamics n. Based on a simple model for local plasticization we have determined a lower bound for n in the order of 5 nm.

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Complex dynamics of hydrogen bonded self-assembling polymers

Cited by 55 publications

References 23 publications

Dynamics of entangled supramolecular polymer networks in presence of high‐order associations of strong hydrogen bonding groups

Dynamics of entangled supramolecular polymer networks in presence of high‐order associations of strong hydrogen bonding groups

Dielectric and Fluorescent Probes To Investigate Glass Transition, Melt, and Crystallization in Polyolefins

Characteristic size of molecular dynamics in polymers probed by dielectric probes of variable length

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