Dynamic mechanical behavior of poly(vinyl‐methyl ether)‐poly(styrene) blends

Cavaillé, J.Y.; Perez, Jonathan; Jourdan, C.; Johari, G. P.

doi:10.1002/polb.1987.090250906

Cited by 29 publications

(21 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the single phase region, the addition of PVME plasticizes PS (Yang ef al., 1986;Schneider and Brekner, 1985), which can be seen in the shifting of the G', G" terminal zone to higher frequencies as the PVME content is increased (Brekner et al, 1985). However, close to the glass transition temperature (approximately Tg+ 5 K), complicated microstructural changes are suggested by a failure of time-temperature superposition (Cavaille et aL, 1987). Stadler et al ( 1988) measured the complex modulus of a PWPVME blend with low molecular weight PVME (MPS/MPVMEQ~O), and found separate relaxations for PVME and PS in the entanglement region.…”

Section: Introductionmentioning

confidence: 99%

Influence of phase separation on the linear viscoelastic behavior of a miscible polymer blend

Mani

Malone

Winter

1992

Journal of Rheology

View full text Add to dashboard Cite

The influence of phase separation on the linear viscoelastic response has been studied in miscible blends of polystyrene and poly(viny1 methyl ether) with a lower critical solution temperature near 110 "C. At temperatures between 25 and 155 'C, and for compositions in the range 20% to 60% polystyrene, the complex moduli G' and G" were measured at frequencies in the range of 0.01 to 100 rad/s. Timetemperature superposition was applied in the single phase region to obtain the complex modulus over eight decades of frequency. Increasing the polystyrene content resulted in an increase in the zero-shear viscosity and a shift of the terminal behavior to lower frequencies or longer times. The phase separation above the lower critical solution temperature was measured as a sudden increase in the fluorescence intensity of an anthracene-labeled polystyrene (approximately 1 wt % in the blend), using an optical probe in the rheometer fixture. For the 20/80 and 4W60 PWPVME samples, the terminal zone was in the accessible frequency window and phase separation was accompanied with a large increase in G' and G". In contrast, the complex modulus of the 60/40 PS/PVME blend could not be measured near the terminal zone and the G' and G" did not exhibit any significant changes near the phase transition temperature.

show abstract

Section: Introductionmentioning

confidence: 99%

Influence of phase separation on the linear viscoelastic behavior of a miscible polymer blend

Mani

Malone

Winter

1992

Journal of Rheology

View full text Add to dashboard Cite

show abstract

“…In the miscible region, addition of PVME plasticizes PS [202][203][204]. Near g the time-temperature superposition principle ( -) is not valid [205], but it is obeyed for deutereous PS below LCST(PS) 40 C [202]. However, at higher temperatures their relaxation times deviate with a magnitude dependent on the molecular weight ratio [206][207][208][209][210].…”

Section: Generalmentioning

confidence: 99%

“…Since blend morphology and kinetics of phase separation are expected to affect the rheological functions, great care is needed in collecting rheological data and interpreting them [223,224]. The two polymers have widely different glass transitions, g (PS) 373-378 and g (PVME) 227-247 K. The g of their blends shows a negative deviation from additivity, that is, PVME acts as a macromolecular solvent/plasticizer of PS, especially when the ratio of molecular weights, w (PS)/ w (PVME), is large [202][203][204][205][206][207][208][209]. When the ratio is about 2, a passage through the phase separation region affects but not , while for the ratio <1 the moduli increase upon entering the phase separation region.…”

Section: Influence Of Thermodynamics On Rheologymentioning

confidence: 99%

Rheology of Polymer Blends

Utracki

2011

Encyclopedia of Polymer Blends

View full text Add to dashboard Cite

The first polymer blend was patented in 1846 and since then blends have became ubiquitous. Blending may provide a full set of material properties, improving processability and/or specific properties. With the advancement of technology there is the notorious growth of complexity -while in the beginning blending involved two polymers, initially without a compatibilizer, more recent commercial alloys have up to five polymers, three compatibilizers, and frequently are reinforced with macro-or nanoparticles [1].Blends are classified as either thermodynamically miscible or immiscible, with the latter dominating. However, imposition of a flow affects the thermodynamic equi librium and it may enhance the miscibility of immiscible blends or vice-versa -there is an interrelation between rheology and thermodynamics. Similarly, flow affects the degree of deformation of the dispersed phase, thus in immiscible blends there are other interrelations between rheology and morphology, which affect the blend performance. To the complexity of polymer alloys and blends (PAB) behavior one must add the incorporation of solids, either in the form of filler and nanofiller particles or by simple fact of blending two components with widely different transition temperatures.Since the flow of PAB is complex, it is useful to revert to simple models, for example, for miscible blends to solutions or mixtures of polymer fractions, for immiscible blends to emulsions or suspensions, and for compatibilized blends to block copolymers (Table 2.1). It is also advisable to study flow behavior of multiphase systems at constant stress (not at constant deformation rate) [2,3].For miscible blends, the free volume theory predicts a positive deviation from the log-additivity rule (PDB, positively deviating blend). However, depending on the system and method of preparation, these blends may show a positive deviation, negative deviation, or additivity [4]. Upon mixing, the presence of specific interac tions may change the free volume and degree of entanglement, which in turn affect the flow behavior [5,6]. For immiscible blends the flow is similarly affected, but in addition there are at least three contributing phases: of the polymeric matrix, of the First Edition. Edited by Avraam I. Isayev.

show abstract

“…The third process is the glass process of the polystyrene phase (2). The low frequency process could be either attributed to shear band process of the polystyrene phase or to a flow process.…”

Section: Analysis Of the Master Curvesmentioning

confidence: 99%

“…This means that the change in temperature modifies the relaxation frequency of all relaxing units by the same shift factor (a T ). This implies that the temperature effect should be a simple activation type, i.e., no chemical or structural changes exist [1][2][3][4]. Consequently, no master curves are available for this class of block copolymers.…”

mentioning

confidence: 99%

Dynamic Mechanical Relaxation Behavior of Block Copolymers: Styrene-Butadiene-Styrene Rubber, SBS

Mansour

Mohammady

2002

Journal of Elastomers & Plastics

View full text Add to dashboard Cite

The real and imaginary parts of the complex shear compliance (J 0 and J 00 ) of styrene-butadiene-styrene block copolymer, SBS, have been measured isothermally over the frequency range; 0.03-30 Hz, at different temperatures ranging from À 70 to 130 C. SBS is taken as representative example of thermoplastic rubbers, which are not susceptible for direct construction of master curves by the usual time-temperature-superposition, tTs, technique. A method has been developed to construct master curves, which we call ''step mastering technique''. The step mastering was carried out by constructing different master curves at different temperatures covering both glass transitions which were then superpositioned as whole to maintain the individual shift factors of different processes unchanged. The relaxation frequency of the low temperature glass process can be obtained at any given reference temperature by fitting and extrapolating the activation curve in order to superposition its low temperature master curve (as whole) on the high temperature master one at the correct position of frequency that corresponds the new reference temperature. Accordingly, it was possible for the first time to construct a complete master curve for J 0 and J 00 for SBS at 30 C.The validity of the master curves obtained by the step mastering technique were confirmed by real frequency measurements in the MHz region using the Quartz method. The analysis showed that the relaxation spectrum consists of four relaxation processes. Using a molecular (meander) model, it was possible Downloaded from from the plateau compliance to determine the size of the structural units of the two phases, which was estimated to be 6.5 and 19.5 nm for PB-and PS-phases, respectively. A possible geometrical packing of the different domains is suggested and compared with the literature data.

show abstract

Dynamic mechanical behavior of poly(vinyl‐methyl ether)‐poly(styrene) blends

Cited by 29 publications

References 20 publications

Influence of phase separation on the linear viscoelastic behavior of a miscible polymer blend

Influence of phase separation on the linear viscoelastic behavior of a miscible polymer blend

Rheology of Polymer Blends

Dynamic Mechanical Relaxation Behavior of Block Copolymers: Styrene-Butadiene-Styrene Rubber, SBS

Contact Info

Product

Resources

About