1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Basic characteristics of uniaxial extension rheology: Comparing monodisperse and bidisperse polymer melts
Rent:
Rent this article for
USD
10.1122/1.3626416
/content/sor/journal/jor2/55/6/10.1122/1.3626416
http://aip.metastore.ingenta.com/content/sor/journal/jor2/55/6/10.1122/1.3626416

Figures

Image of FIG. 1.
FIG. 1.

Small amplitude oscillatory shear measurements of (a) the pure melts and (b) the bimodal blends at room temperature. The storage modulus and the loss modulus are represented by the open and filled symbols, respectively.

Image of FIG. 2.
FIG. 2.

Engineering stress as a function of Hencky strain for SBR240K at various strain rates. The straight dashed line provides an indication of how the engineering stress increases more weakly than linearly with the Hencky strain.

Image of FIG. 3.
FIG. 3.

Engineering stress as a function of Hencky strain for SBR1M at various strain rates. The stretching, ending in yielding-initiated failure and rupture, is represented by filled and open symbols respectively. The dotted curve is the neo-Hookean formula of Eq. (1) with G = Gpl = 0.85 MPa from Table I, showing exponential growth with the Hencky strain ɛ.

Image of FIG. 4.
FIG. 4.

Engineering stress as a function of Hencky strain at various strain rates for the 240K/1M (90:10) blend, exhibiting two yield points associated with the breakdown of the entanglement networks made of SBR240K and SBR1M, respectively.

Image of FIG. 5.
FIG. 5.

Engineering stress as a function of Hencky strain at various strain rates for the 240K/1M (80:20) blend. At the rates of 2.0, 3.0, 6.0, and 10 s−1, the blend underwent two yield points corresponding to the collapse of the entanglement networks made of SBR240K and SBR1M, respectively. At the highest applied rate of 15 s−1, the entanglement network associated with SBR240K yields, but the second network made of SBR1M continues to stretch until rupture.

Image of FIG. 6.
FIG. 6.

Engineering stress as a function of Hencky strain at various strain rates for the 70K/1M (80:20) blend. The stretching, yielding-initiated failure and rupture, is represented by filled and open symbols respectively.

Image of FIG. 7.
FIG. 7.

Failure Hencky strain as a function of applied strain rate for SBR1M, SBR240K and the two bimodal blends. The solid symbols represent ductile failure through yielding. The dashed lines show the borderline between viscoelastic and elastic regimes for the two blends. The open symbols denote strains at rupture for the pure SBR1M (open squares) and the 240K/1M (80:20) blend (open triangle).

Image of FIG. 8.
FIG. 8.

Engineering stress as a function of time in step relaxation experiments for the SBR240K melt.

Image of FIG. 9.
FIG. 9.

Engineering stress as a function of time in step relaxation experiments for (a) the SBR240K melt and the 240K/1M (90:10) blend, and (b) 240K/1M (80:20) blend.

Image of FIG. 10.
FIG. 10.

Comparison of the engineering stress-strain curves for the SBR240K melt and the 240K/1M (90:10) blend.

Image of FIG. 11.
FIG. 11.

Cauchy stress σ = σengrλ as a function of Hencky strain for the 240K/1M (80:20) blend. The dotted line represents the stress-strain curve from the neo-Hookean model of Eq. (1) with G = Gpl = 0.82 MPa from Table I.

Image of FIG. 12.
FIG. 12.

(a) Transient extensional viscosity as a function of time for the SBR240K melt, where the “linear response” data given by from the small amplitude oscillatory shear measurements are also presented as the reference [Gleissle (1980)]. (b) Comparison of the difference between the dashed straight line and the diamonds in Fig. 2 with the exponential increase associated with areal shrinkage involved in the denominator of true stress and transient viscosity.

Image of FIG. 13.
FIG. 13.

(a) Transient extensional viscosity as a function of time for SBR1M, where the linear response data given by from the small amplitude oscillatory shear measurements are also presented as a reference [Gleissle (1980)]. (b) Engineering stress σengr versus the stretching ratio λ at , relative to a neo-Hookean curve of Eq. (1) based on G = 0.34 MPa = 0.4Gpl, which implies that entanglement spacing has enlarged from Me0 to 2.5 Me0 at the stretching ratio of λnG ∼ 8.5. Elsewhere, we show [Wang and Wang (2011) that the equilibrium entanglement strand would reach full extension at a stretching ratio λ* ∼ 4, and higher stretching occurs because some equilibrium entanglements were removed during extension so that there are longer strands between the remaining entanglements.

Image of FIG. 14.
FIG. 14.

(a) Transient extensional viscosity as a function of time for the 240K/1M (80:20) blend, where the linear response data given by from the small amplitude oscillatory shear measurements are also presented as a reference [Gleissle (1980)]. (b) Engineering stress σengr versus the stretching ratio λ at the various rates for the 70K/1M (80:20) blend, relative to a neo-Hookean curve of Eq. (1) based on G(φ) = Gpl φ2.3 = 0.021 MPa where Gpl = 0.85 MPa for the pure SBR melt and φ = 0.2.

Tables

Generic image for table
TABLE I.

The molecular characteristics of SBR melts.

Loading

Article metrics loading...

/content/sor/journal/jor2/55/6/10.1122/1.3626416
2011-09-02
2014-04-18
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Basic characteristics of uniaxial extension rheology: Comparing monodisperse and bidisperse polymer melts
http://aip.metastore.ingenta.com/content/sor/journal/jor2/55/6/10.1122/1.3626416
10.1122/1.3626416
SEARCH_EXPAND_ITEM