On the use of time-temperature superposition in multicomponent/multiphase polymer systems

Han, Chang Dae; Kim, Jin Kon

doi:10.1016/0032-3861(93)90585-x

Cited by 183 publications

(31 citation statements)

References 36 publications

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“…The slopes of the log G ′ versus log G ″ plots for the blends were smaller to those for pure components. This suggests that all of the PLA/PBSA blends were immiscible and confirmed the results of the SEM observations 19. A comparison between the modified Cole–Cole plots of the blends without chain extender and compounds with chain extender revealed that the deviation from the terminal relation (i.e., G ′– G ″ 2 generally observed for linear polymers) became more pronounced in compounds with chain extender.…”

Section: Resultssupporting

confidence: 83%

“…The Cole–Cole plot represents an empirical correlation between η″ and η′. However, the modified Cole–Cole plot (the curve of log G ′ vs log G ″) at a fixed temperature has been used widely for the evaluation of structural changes in polymer blends and filled polymer systems 19–21. The modified Cole–Cole plots for the pure components, blends without chain extender, and compounds with chain extender are presented in Figure 11(b).…”

Section: Resultsmentioning

confidence: 99%

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Effect of a chain extender on the rheological and mechanical properties of biodegradable poly(lactic acid)/poly[(butylene succinate)‐co‐adipate] blends

Eslami

Kamal

2013

J of Applied Polymer Sci

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Biodegradable polymer blends based on poly(lactic acid) (PLA) and poly[(butylene succinate)-co-adipate] (PBSA) were prepared with a laboratory internal mixer. An epoxy-based, multifunctional chain extender was used to enhance the melt strength of the blends. The morphology of the blends was observed with field emission scanning electron microscopy. The elongational viscosities of the blends, with and without chain extender, were measured with a Sentmanat extensional rheometer universal testing platform. The blends with chain extender exhibited strong strain-hardening behavior, whereas the blends without chain extender exhibited only weak strain-hardening behavior. Measurements of the linear viscoelastic properties of the melts suggested that the chain extender promoted the development of chain branching. The results show that PBSA contributed to significant improvements in the ductility of the PLA/PBSA blends, whereas the chain extender did not have a significant effect on the elastic modulus and strain at break of the blends. The combined blending of PLA with PBSA and the incorporation of the chain extender imparted both ductility and melt strength to the system. Thus, such an approach yields a system with enhanced performance and processability.

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Section: Resultssupporting

confidence: 83%

Section: Resultsmentioning

confidence: 99%

Effect of a chain extender on the rheological and mechanical properties of biodegradable poly(lactic acid)/poly[(butylene succinate)‐co‐adipate] blends

Eslami

Kamal

2013

J of Applied Polymer Sci

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“…This can be associated with changes in the structure and morphology of the samples. The structural changes due to the chain extension reaction could also be tracked by the Cole–Cole plot (the curve of η″, the out‐of‐phase component of complex viscosity vs. η′, the dynamic viscosity) and the modified Cole–Cole plot (the curve of log G ′ vs. log G ″) at a constant temperature . Figure (a) shows a concave Cole–Cole curve close to a semicircle for Pure PLAs.…”

Section: Resultsmentioning

confidence: 99%

Reactive extrusion effects on rheological and mechanical properties of poly(lactic acid)/poly[(butylene succinate)‐co‐adipate]/epoxy chain extender blends and clay nanocomposites

Mirzadeh

Ghasemi

Mahrous

et al. 2015

J of Applied Polymer Sci

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Poly(lactic acid) (PLA), a biosource, biodegradable polymer, is not suitable for some important polymer processing operations, such as film blowing and blow molding, due to its low melt strength. Moreover, while it has high tensile modulus and strength in the solid state, it exhibits low ductility. The present work is an extension of our earlier effort to improve the processability and mechanical properties of PLA by blending with poly[(butylene succinate)‐co‐adipate)] (PBSA), a biodegradable polymer with lower glass transition temperature. We evaluate the influences of incorporation of an epoxy chain extender and nanoclay on the properties of the blend. Since earlier work was conducted in a batch mixer, the influence of melt processing in the twin screw extruder and the differences between products obtained in the extruder and the batch mixer are evaluated and explained. Based on earlier work, the following PLA/PBSA blend ratios of 90:10, 80:20 and 70:30 were selected. All the samples were prepared in the twin‐screw extruder at two different screw speeds (50 and 150 rpm), to evaluate the effects of residence time and shear rates. The morphology and structure of the blends were examined using field emission scanning electron microscopy. Transmission electron microscopy (TEM) and X‐ray diffraction (XRD) were used to evaluate the levels of intercalation and exfoliation in the nanocomposites. The chain extension reaction was evaluated using nuclear magnetic resonance (NMR) spectroscopy and other techniques. Rheological properties (dynamic oscillatory shear and elongational viscosity measurements) and mechanical characteristics of the pure components, blends, and nanocomposites were studied and discussed in light of the composition and morphology of the blends and the nanocomposites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42664.

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“…Crystallinity can be detected via differential scanning calorimetry (DSC), but we could not detect any enthalpic DSC signature of such crystallinity. However, DSC measurements can be insensitive to very small crystal fractions or small crystal domain sizes;33 correspondingly, the possibility of microcrystallinity cannot be eliminated. The observation that polybutadiene and EPDM do not exhibit anomalous b T behavior seen in SBR lends some support to the styrene ring stacking mechanism.…”

Section: Discussionmentioning

confidence: 99%

A critical analysis of the effect of crosslinking on the linear viscoelastic behavior of styrene–butadiene rubber and other elastomers

Prabhu

Klitkou

Medvedev

et al. 2013

J Polym Sci B Polym Phys

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The linear viscoelastic behavior in dynamic shear and tensile creep at temperatures from À30 to 70 C is measured for an styrene-butadiene rubber (SBR) elastomer cured with dicumyl peroxide to crosslinking densities between 0 and 23.5 Â 10 À5 mol/cm 3 . The G 0 , G 00 , and tan d isotherms are analyzed by time-temperature superposition (TTS), where the tan d master curves are consistent with those of Mancke and Ferry. However, to achieve the TTS in the lightly crosslinked SBR systems, an anomalous vertical shift is required in the narrow temperature region from 10 to 30 C. The vertical shift factor in this temperature region is not the standard q 0 T 0 =qT from rubber elasticity. No anomalous behavior is detected in the equilibrium modulus, which is a linear function of temperature in accordance with the classical theory of rubber elasticity. In contrast to SBR, standard vertical shifts are required to effect TTS for uncrosslinked polybutadiene and an ethylene propylene diene monomer elastomer.

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On the use of time-temperature superposition in multicomponent/multiphase polymer systems

Cited by 183 publications

References 36 publications

Effect of a chain extender on the rheological and mechanical properties of biodegradable poly(lactic acid)/poly[(butylene succinate)‐co‐adipate] blends

Effect of a chain extender on the rheological and mechanical properties of biodegradable poly(lactic acid)/poly[(butylene succinate)‐co‐adipate] blends

Reactive extrusion effects on rheological and mechanical properties of poly(lactic acid)/poly[(butylene succinate)‐co‐adipate]/epoxy chain extender blends and clay nanocomposites

A critical analysis of the effect of crosslinking on the linear viscoelastic behavior of styrene–butadiene rubber and other elastomers

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