Cooperative structure formation by combination of covalent and association chain polymers: 4. Designing functional groups for supramolecular structure formation

Hilger, Christopher; Stadler, Reimund

doi:10.1016/0032-3861(91)90148-c

Cited by 50 publications

(36 citation statements)

References 6 publications

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“…However, the data of dielectric and dynamical measurements did not coincide1 (Figure 1). The characteristic deviations between the two data sets (see part 4) were not explained in our previous w0rk.l…”

mentioning

confidence: 92%

On the Motional Coupling between Chain and Junction Dynamics in Thermoreversible Networks

Müller¹,

Stadler²,

Kremer³

et al. 1995

Macromolecules

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The dielectric relaxation of polar stickers capable of binary hydrogen bond complexation is studied theoretically and compared to experiment. In the model system, free and complexed units are considered in equilibrium. The theoretical evaluation shows that the dipole correlation function of complexes cannot be described by a simple exponential decay, as is usually assumed in dielectric spectroscopy. Complex reorientation and dissociation contribute simultaneously to the dielectric relaxation. The theoretical results are compared to experimental data obtained on polybutadiene which is functionalized at low concentration (x = 0.02, 0.03, and 0.04) by 4-phenyl-1,2,4-triazoline-3,5-dione (4-phenylurazole (PU)) units. From the comparison of recent dielectric and dynamic mechanical measurements, the relaxation times of the reorientation of dimeric complexes are calculated and compared with the lifetime of dimeric contacts. From the relaxation strength of the relaxation of complexed urazoles, the dipole moment is calculated and compared with the result of a force field calculation. Both methods reveal a slightly twisted structure of the dimeric complexes.

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confidence: 92%

On the Motional Coupling between Chain and Junction Dynamics in Thermoreversible Networks

Müller¹,

Stadler²,

Kremer³

et al. 1995

Macromolecules

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“…Formation of these ordered domains depends sensitively on the steric requirements of the polymer backbone to which the functional group is attached [lo, 111, as well as on the chemical structure of the functional group [12,13]. In a previous paper [12] we have shown that in case of the meta-isomer of U4A, i.e. 3-urazoylbenzoic acid (U3A) groups 2, no ordered structures are formed by the functional groups in the polymer matrix.…”

Section: Introductionmentioning

confidence: 99%

Cooperative self‐assembling in statistical copolymers: a new approach to high‐temperature thermoplastic elastomers

Hellmann

Hilger

Stadler

1994

Polymers for Advanced Techs

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Based on previous work, where it was shown that 4‐urazoylbenzoic acid (U4A) groups, which are attached statistically to polybutadiene, form ordered supramolecular arrays in the unpolar polymer matrix, the present work describes the synthesis of a new molecular building block capable of self‐assembling in the unpolar polymer matrix. 5‐Urazoylisophthalic acid (U35A) groups attached to 1,4‐polybutadiene chains cause the formation of a thermoplastic elastomer of improved properties. The clusters of functional groups show an endothermic transition. The melting temperature increases for low levels of modification from 130°C up to 190°C. The mechanical properties (stress–strain and dynamic mechanical) reveal excellent rubbery characteristics and a rubbery plateau which is considerably flatter than those of technical grade thermoplastic elastomers. The IR data indicate that the U35A groups are tetrafunctional with respect to supramolecular self‐assembling. Based on detailed knowledge of the structure of the self‐assembled domains in U4A groups, a model is developed which describes the observed material properties qualitatively.

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“…1). Compared to formerly investigated homopolymer systems, [18][19][20] our copolymer system exhibits markedly improved mechanical properties. The choice of styrenebutadiene copolymers additionally allows for the adjustment of the glass transition temperature and hence for the control of the mechanical properties of the polymer.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen bonding and thermoplastic elastomers – a nice couple with temperature-adjustable mechanical properties

et al. 2018

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ab Styrene-butadiene copolymers are modified with varying fractions of benzoic acid moieties being able to perform hydrogen bonding. This is done by using a simple synthetic approach which utilizes click chemistry. Temperature-dependent dynamic mechanical properties are studied, and it turns out that even the apparently rather simple hydrogen bonding motif has a marked impact on the material properties due to the fact that it facilitates the formation of a supramolecular polymer network. Besides a glass transition, the investigated functionalized copolymers exhibit a second endothermic transition, known as a quasi-melting. This is related to the opening of the hydrogen bonding complexes.Additionally to dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), temperaturedependent infrared (IR) spectroscopy and small angle X-ray scattering (SAXS) are used to understand the structure-property relationships.

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Cooperative structure formation by combination of covalent and association chain polymers: 4. Designing functional groups for supramolecular structure formation

Cited by 50 publications

References 6 publications

On the Motional Coupling between Chain and Junction Dynamics in Thermoreversible Networks

On the Motional Coupling between Chain and Junction Dynamics in Thermoreversible Networks

Cooperative self‐assembling in statistical copolymers: a new approach to high‐temperature thermoplastic elastomers

Hydrogen bonding and thermoplastic elastomers – a nice couple with temperature-adjustable mechanical properties

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