Structural studies of poly(p-phenylene selenide) doped with sulphur trioxide

Czerwiński, Wojciech; Kreja, L.; Hruszka, P.; Jurga, J.; Brycki, Bogumił

doi:10.1007/bf01130135

Cited by 2 publications

(2 citation statements)

References 16 publications

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“…These energies are also in better agreement with calculated estimations for the rotation of crankshafts than the β processes. Moreover, we also notice a better agreement with the experimental values revealed by NMR in dilute solutions of PPS 43,44 (E a (γ,PPS) is close to 14 kJ/mol) and in BPA-PC 45,46 (13 kJ/mol). This leads us to assign the γ relaxation modes to very local rearrangements of a few rings, such as crankshaft-like motions, with possibly a small influence of neighboring chain portions.…”

Section: Resultssupporting

confidence: 84%

Molecular Mobility in Para-Substituted Polyaryls. 3. Low-Temperature Dynamics

David¹,

Girard²,

Dolmazon³

et al. 1996

Macromolecules

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The low-temperature mechanical relaxations in poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene [poly(aryl ether ether ketone, PEEK], poly(thio-1,4-phenylene) [poly(phenylene sulfide), PPS], and poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene), [poly(aryl ether sulfone), PES] are investigated. All three polymers exhibit a low-temperature γ relaxation, in the temperature range from 40 to 100 K at 1 Hz. The apparent activation energies for the γ relaxations (15−25 kJ/mol) are close to the values derived from empirical force field molecular mechanics calculations of the “crankshaft motion” in an isolated chain portion. Only polymers with a polar interaromatic bridge (PEEK and PES) exhibit another secondary β relaxation, in the temperature range from 100 to 250 K at 1 Hz. Moreover, the apparent activation energies of the β processes are significantly higher than the activation energies of the γ relaxations. Therefore, it is concluded that polar intermolecular interactions play an important role in the molecular events leading to the β relaxation, whereas the γ relaxation is due to conformational changes mostly controlled by an intramolecular energy.

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Section: Resultssupporting

confidence: 84%

Molecular Mobility in Para-Substituted Polyaryls. 3. Low-Temperature Dynamics

David¹,

Girard²,

Dolmazon³

et al. 1996

Macromolecules

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show abstract

“…For all samples the magnetization recovery function was single-exponential in the whole range of temperatures, to the accuracy of 3% what means that between different phases, characterizing dissimilar molecular dynamics, appears the effective spin-diffusion process [9,11]. On the low temperature side the relaxation times for nanocomposites show a very weak temperature independence what is supposed to be dictated by the nuclear spin diffusion toward the electron spin in paramagnetic impurities [12]. From 200 K relaxation times start to decrease and do not achieve a minimum due to experimental limitations.…”

Section: Spin-lattice Relaxation Timesmentioning

confidence: 99%

Molecular dynamics of poly(ethylene terephthalate)/poly(phenylene sulfide) nanocomposites with barium titanate

et al. 2011

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Abstract:The relaxation processes and the properties of polymer/ceramic nanocomposites have been studied by the 1 H nuclear magnetic resonance methods. Nanocomposites of poly(ethylene terephthalate) PET and poly(phenylene sulfide) PPS with 0.25, 2.5 and 5% wt. barium titanate BT were prepared using a twin screw extruder and injection moulding machine. The spin-lattice relaxation time T 1 , second moment M 2 and the motional parameters as e.g. the activation energies in the nanocomposites were investigated. PACS

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Structural studies of poly(p-phenylene selenide) doped with sulphur trioxide

Cited by 2 publications

References 16 publications

Molecular Mobility in Para-Substituted Polyaryls. 3. Low-Temperature Dynamics

Molecular Mobility in Para-Substituted Polyaryls. 3. Low-Temperature Dynamics

Molecular dynamics of poly(ethylene terephthalate)/poly(phenylene sulfide) nanocomposites with barium titanate

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