Molecular weight and polydispersity effects at polymer-polymer interfaces

Broseta, Daniel; Fredrickson, Glenn H.; Helfand, Eugene; Leibler, Ludwik

doi:10.1021/ma00203a023

Cited by 317 publications

(274 citation statements)

References 8 publications

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“…The interfacial width would, in a real case, be somewhere between these two extremes. The predicted interfacial width for this system without block copolymer is approximately 15 A, as calculated using the theory of Broseta et al 39 . The interfacial width would be expected to increase with block copolymer present, as has been observed by neutron reflectivity for the PS/PMMA system4°.…”

Section: Pbd-cooh/pdms-nh 2 Model Resultsmentioning

confidence: 51%

Interfacial modification through end group complexation in polymer blends

Fleischer¹,

Morales²,

Koberstein³

1994

Macromolecules

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Section: Pbd-cooh/pdms-nh 2 Model Resultsmentioning

confidence: 51%

Interfacial modification through end group complexation in polymer blends

Fleischer¹,

Morales²,

Koberstein³

1994

Macromolecules

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“…Figure 6 displays the prediction of G c as a function of ⌺ eff (solid line) v. The experimental G c values obtained by us 22 as a function of ⌺ eff for N ϭ 1370 at T ϭ 175°C (filled circles) and T ϭ 150°C (filled squares). Interfacial widths used to evaluate G c in eq 8 are calculated using the expression derived by Helfand and coworkers 37,38 as shown in eq 15. The infinite molecular weight expression 37 is used in place of the finite chain-length expression 38 The predictions agree with the data.…”

Section: Resultsmentioning

confidence: 99%

“…37,38 Therefore eq 8 states that in the limit of a I ϭ 0, the system is immiscible ( ӷ s , where s is at the spinodal), no entanglements develop, and G c ϭ G c-pullout . As the system becomes more miscible ( 3 s ), the interfacial width (relative to L e ) increases, and the probability to form entanglements increases resulting in the increased probability that crazing will contribute more significantly as the mechanism of fracture.…”

Section: The Modelmentioning

confidence: 99%

Relating fracture energy to entanglements at partially miscible polymer interfaces

Gorga

Narasimhan

2002

J Polym Sci B Polym Phys

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A new model has been developed to calculate the areal chain density of entanglements (⌺ eff ) at partially miscible polymer-polymer interfaces. The model for ⌺ eff is based on a stochastic approach that considers the miscibility of the system. The values agree between ⌺ eff calculated from the model and literature values for the reinforced interfaces. Using ⌺ eff calculated from the model, the interfacial width, and the average distance between entanglements, an equation for the fracture energy of nonreinforced polymer interfaces is proposed. This equation is used to model the transition from chain pullout to crazing. As a function of system miscibility, the model for ⌺ eff also accurately predicts a maximum in mode I fracture energy (G c ) as a result of the transition from gradient-driven to miscibility-limited interdiffusion, which is observed experimentally. As ⌺ eff increases, the fracture energy increases accordingly. Compared with a recent model developed by Brown, the new model correctly predicts a reduced G c (attributed to chain pullout) when the interfacial width is less than the average distance between entanglements. Theoretical predictions of the change in fracture energy with respect to interfacial width agree with the experimental measurements. Finally, it is postulated that the use of a miscibility criterion for G c may reveal the universal nature of the pullout to crazing transition.

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“…We find several studies reported on the interfacial properties in terms of interdiffusion at the interface, [22][23][24][25][26] interfacial tension, [27][28][29][30] and interface width, 21,[31][32][33][34] and so forth in polymer blends. The magnitude and behavior of interface width with varying molecular weight, temperature, and film thickness have also been studied using the small angle neutron scattering, neutron reflectometry, 27,28,[33][34][35] small angle X-ray scattering, differential scanning calorimetry (DSC), 26 transmission electron microscopy, 30 and so forth with varying success.…”

Section: Introductionmentioning

confidence: 92%

“…The magnitude and behavior of interface width with varying molecular weight, temperature, and film thickness have also been studied using the small angle neutron scattering, neutron reflectometry, 27,28,[33][34][35] small angle X-ray scattering, differential scanning calorimetry (DSC), 26 transmission electron microscopy, 30 and so forth with varying success. Schnell et al 5 had studied interfaces in blends of polystyrene with either poly (p-methylstyrene) or a statistical copolymer poly(styrene-co-pbromostyrene) using neutron reflection method.…”

Section: Introductionmentioning

confidence: 99%

A new insight into interface widths in binary polymer blends based on ortho‐positronium lifetime studies

Ramya

Ranganathaiah

2012

J of Applied Polymer Sci

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The interface widths in two immiscible polymer blend (Poly vinyl chloride (PVC)/Polystyrene (PS)) and PVC/Ethylene Vinyl Acetate (EVA) are determined experimentally using hydrodynamic interaction approach through free volume measurement by positron annihilation lifetime spectroscopy. For comparison, the same study is performed in a miscible blend (Styrene Acrylonitrile (SAN)/Poly Methyl Methacrylate (PMMA)). The interfacial width (Dl) is evaluated from the hydrodynamic interaction (a) based on Kirkwood-Risemann theory and friction coefficient from Stokes equation. Friction at the interface of a binary blend evidences how close the surfaces of the polymer chains come or stay apart which in turn depends on the type of force/interaction at the interface. In this work, we define interface width from a different perspective of Flory-Huggins interaction approach. Measured composition dependent interface widths in the three blends studied clearly demonstrate the sensitivity of the present method. In miscible blend, high friction at the interface results in stronger hydrodynamic interaction and hence smaller interface widths (0.36-1.97 Å ), whereas weak or no interaction in immiscible blends produce wider widths (2.81-25.0 Å ).

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Molecular weight and polydispersity effects at polymer-polymer interfaces

Cited by 317 publications

References 8 publications

Interfacial modification through end group complexation in polymer blends

Interfacial modification through end group complexation in polymer blends

Relating fracture energy to entanglements at partially miscible polymer interfaces

A new insight into interface widths in binary polymer blends based on ortho‐positronium lifetime studies

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