In situ investigation of SBR vulcanization: A combined study of1H-NMR and vulcametry

Fülber, C.; Unseld, K.; Herrmann, Volker; Jakob, K.; Blümich, Bernhard

doi:10.1007/bf00665635

Cited by 14 publications

(13 citation statements)

References 8 publications

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“…The torque G is used as an independent measure of the cross-link density, according to the standard relation G ≅ nk B T ∝ N -1 k B T , in which n is the cross-link density, i.e. the number of cross-linked chains per unit volume may be considered as roughly linear.…”

Section: Resultsmentioning

confidence: 99%

Effect of Residual Dipolar Interactions on the NMR Relaxation in Cross-Linked Elastomers

et al. 1996

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For elastomer networks above the glass transition temperature Tg, a unified approach is presented to relate the residual dipolar couplings in various independent NMR experiments to the crosslink density. This is demonstrated on a series of cross-linked poly(styrene-co-butadiene) elastomers. The presence of dynamic physical and permanent chemical cross-links leads to a nonzero average of the homonuclear and heteronuclear dipolar couplings, which results in a solid-like NMR relaxation behavior. The residual dipolar couplings are expressed as a function of the effective number of statistical segments Ne between the physical and N e X between the chemical cross-link points, using a simplified network model with Gaussian statistics. These effective numbers are extracted for each sample of the series from the 13 C-edited transverse 1 H magnetization relaxation of the CH group. It is shown that the respective Ne values can be used to scale the time domain of various NMR experiments such as (a) the free induction decay, (b) the 13 C-edited 1 H transverse magnetization relaxation, (c) the cross-polarization curves, and (d) the 1 H magnetization exchange between the CH and CH2 groups. This proves the validity of the unified view on the dipolar interactions in elastomer networks and provides a way to estimate the cross-link density.

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Section: Resultsmentioning

confidence: 99%

Effect of Residual Dipolar Interactions on the NMR Relaxation in Cross-Linked Elastomers

et al. 1996

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“…It was shown by Smith et al28 that the method provides a variety of structural detail, that is, structural voids, compression‐, and reaction‐induced gradients of chain segment mobility of elastomers of different crosslinking densities. And during the work of C. Fülber et al,29 the vulcanization as a function of time was presented. Here we applied the XLDS‐15 NMR spectrometer to study the reversion of our object rubber blend.…”

Section: Resultsmentioning

confidence: 99%

An effect of OMMT on the anti‐reversion in NR/CR blend system

Zhang

Huang

Liu

2008

J of Applied Polymer Sci

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The influence of dispersed organomodified montmorillonite (OMMT) on curing behaviors of natural rubber (NR)/chloroprene rubber (CR) blend was investigated. The preparing procedure includes premixed rubber individually with its additives and then the two components were blended according to gum weight ratio for NR to CR is 75/25. Sulfur was chosen as the vulcanizing agent, and the research on vulcanization was carried through the rotor-Rheometer at 143 C. Transmission electron microscopy showed the dispersion of OMMT in the rubber blends and detected little OMMT migrated into the NR phase. The scorch time (t 10 ), optimum vulcanizing time (t 90 ), and reversion phenomenon were both measured by the curing curve; meanwhile, the crosslinking densities and mechanical properties were determined through equilibrium swelling-method, magnetic resonance crosslink density spectrometer, and tensile tests. By comparing the test results, an interesting phenomenon was discovered and furthermore was verified that the addition of OMMT can obviously modify the reversion resistance of the binary blend.

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“…In addition, a modification by grafting a proper functional organic silane into the hydroxyl groups present on the edges of the clay platelets has been found to be an efficient way to better disperse the nanoparticles in the polymer matrix via the reaction of the APTES with the polymer matrix in the nanocomposites . The functionalization of clay minerals with organosilanes can take place at three different sites: at the interlayer space, at the external surface and at the edges . In contrast to common observations during the intercalation of small molecules between the silicate layers, where longer organic chains normally result in higher interlayer spacing, a reverse trend is observed for aminosilane‐Mt systems .…”

Section: Methodsmentioning

confidence: 99%

Reaction kinetics of polyfurfuryl alcohol bioresin and nanoparticles by ¹H‐NMR transverse relaxation measurements

2017

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The polymerization of Furfuryl Alcohol (FA) was studied systematically by NMR transverse relaxation. A special focus is on the impact of nanoparticles (BTN, TMOA, and APTES) on the reaction kinetic of the resin's polycondensation. The NMR spin-spin relaxation rate (R 2 ) was measured by the Carr-Purcell-Meiboom-Gill (CPMG) multiecho sequence. The molecular mobility of the resin's molecules during reaction could be followed by R 2 as a function of curing time. R 2 for the chain protons increased with reaction time. R 2 increased faster in the presence of nanoclay, thus, nanoclay acts as a sort of catalyst in FA polymerization. The results strongly suggest that entanglements and filler-induced packing disruption play a major role in polymer dynamics. Based on the experimental data, the curing kinetics was modeled by considering both chemical and diffusion-controlled autocatalytic kinetic models. The order of the overall reaction was found to be approximately 2. POLYM. COMPOS., 00:000-000, FIG. 2. Transverse relaxation rates as a function of curing reaction time t. Exemplarily, the data of the curing reaction for FA with 3.5% wt PTSA are shown. They are representative for the investigated reactions. The line indicates the starting time of reaction modeling after an equilibration period.

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In situ investigation of SBR vulcanization: A combined study of1H-NMR and vulcametry

Cited by 14 publications

References 8 publications

Effect of Residual Dipolar Interactions on the NMR Relaxation in Cross-Linked Elastomers

Effect of Residual Dipolar Interactions on the NMR Relaxation in Cross-Linked Elastomers

An effect of OMMT on the anti‐reversion in NR/CR blend system

Reaction kinetics of polyfurfuryl alcohol bioresin and nanoparticles by ¹H‐NMR transverse relaxation measurements

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In situ investigation of SBR vulcanization: A combined study of1H-NMR and vulcametry

Cited by 14 publications

References 8 publications

Effect of Residual Dipolar Interactions on the NMR Relaxation in Cross-Linked Elastomers

Effect of Residual Dipolar Interactions on the NMR Relaxation in Cross-Linked Elastomers

An effect of OMMT on the anti‐reversion in NR/CR blend system

Reaction kinetics of polyfurfuryl alcohol bioresin and nanoparticles by 1H‐NMR transverse relaxation measurements

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Product

Resources

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Reaction kinetics of polyfurfuryl alcohol bioresin and nanoparticles by ¹H‐NMR transverse relaxation measurements