The influence of the molecular mass of two incompatible polymers on their miscibility in the solid state without compatibilizer after casting from solution

Dondos, Anastasios; Christopoulou, V.; Papanagopoulos, D.

doi:10.1002/(sici)1099-0488(19990215)37:4<379::aid-polb11>3.0.co;2-k

Cited by 17 publications

(5 citation statements)

References 9 publications

(10 reference statements)

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“…In as-cast films from solutions in chloroform of sample 180 6 −65 6 , no phase separation is visible, suggesting that both types of arms are in a mixed state. This nonequilibrium state is due to the short length of the P2VP blocks (the system is close to the order−disorder transition) as well as to the fact that mixing of the blocks is facilitated by the use of a common good solvent for PS and P2VP. , For all other samples, rapid casting from solutions in chloroform results in a lamellar morphology (Figure ). Upon annealing, we should observe either an evolution of the period of the lamellae toward the equilibrium size or a transition from lamellae to cylinders or spheres.…”

Section: Resultsmentioning

confidence: 99%

A Comparative Experimental and Theoretical Study between Heteroarm Star and Diblock Copolymers in the Microphase Separated State

et al. 2000

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A pronounced difference in the behavior of heteroarm star copolymers from the conventional diblock copolymers is analyzed theoretically and experimentally on the example of symmetric polystyrene-poly(2-vinylpyridine) (PS6P2VP6) star block copolymer melts. Microphase separation of PS6P2VP6 stars with volume fraction of PS varying from 0.30 to 0.75 is studied using transmission electron microscopy (TEM). The observed (lamellar, cylindrical and undefined “bicontinuous-like”) structures often turned out to be different from that expected for the corresponding diblock copolymers. The dependence of the long period of lamellar structures of heteroarm star block copolymers on block length is found to deviate in a systematic way from N 2/3 law (known for diblock copolymers), especially for the stars of high functionality. The theoretical model proposed to describe an extra-stretching of star block copolymers near the lamellar interface is found to be successful in prediction of block length and star functionality dependence of the lamellar period as it agrees remarkably well with the present and other available experimental data for both symmetric and asymmetric heteroarm star block copolymers.

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Section: Resultsmentioning

confidence: 99%

A Comparative Experimental and Theoretical Study between Heteroarm Star and Diblock Copolymers in the Microphase Separated State

et al. 2000

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“…The blends containing other SMMA copolymers such as SMMA 5, SMMA 15 and SMMA 25 also exhibit a similar trend. The miscibility of a polymer mixture obtained after removal of the solvent gradually reduces as the difference between their molecular weight increases 26. Since the molecular weight of the copolycarcarbonates synthesized were lower than that of the homopolycarbonate as listed in Table 1, better miscibility of binary blends than ternary blends might not stem from the effects of molecular weight.…”

Section: Resultsmentioning

confidence: 99%

Phase behavior of ternary blends containing dimethylpolycarbonate, tetramethylpolycarbonate and poly[styrene‐co‐(methyl methacrylate)] copolymers (or polystyrene)

Kim

Yoo

Kim

2004

Polymer International

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The miscibility and phase behavior of ternary blends containing dimethylpolycarbonate (DMPC), tetramethylpolycarbonate (TMPC) and poly[styrene‐co‐(methyl methacrylate)] copolymer (SMMA) have been explored. Ternary blends containing polystyrene (PS) instead of SMMA were also examined. Blends of DMPC with SMMA copolymers (or PS) did not form miscible blends regardless of methyl methacrylate (MMA) content in copolymers. However, DMPC blends with SMMA (or PS) blends become miscible by adding TMPC. The miscible region of ternary blends is compared with the previously determined miscibility region of binary blends having the same chemical components and compositions. The region where the ternary blends are miscible is much narrower than that of binary blends. Based on lattice fluid theory, the observed phase behavior of ternary blends was analyzed. Even though the term representing the Gibbs free energy change of mixing for certain ternary blends had a negative value, blends were immiscible. It was revealed that a negative value of the Gibbs free energy change of mixing was not a sufficient condition for miscible ternary blends because of the asymmetry in the binary interactions involved in ternary blends. Copyright © 2004 Society of Chemical Industry

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“…The observed changes in the miscibility of HA and PVP were related to the molecular weights of the HAs. It is well known that polymers with relatively similar low molecular weights tend to be more miscible [32]. The higher molecular weight of HA II was probably responsible for the clearly negative value of the miscibility parameter.…”

Section: Viscometric Studiesmentioning

confidence: 94%

Characterisation of Hyaluronic Acid Blends Modified by Poly(N-Vinylpyrrolidone)

Lewandowska

Szulc

2021

Molecules

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The viscosity behaviour and physical properties of blends containing hyaluronic acid (HA) and poly(N-vinylpyrrolidone) (PVP) were studied by the viscometric technique, steady shear tests, tensile tests and infrared spectroscopy. Viscometric and rheological measurements were carried out using blends of HA/PVP with different HA weight fractions (0, 0.2, 0.5, 0.8 and 1). The polymer films and HA/PVP blend films were prepared using the solution casting method. The study of HA blends by viscometry showed that HA/PVP was miscible with the exception of the blend with high HA content. HA and its blends showed a shear-thinning flow behaviour. The non-Newtonian indices (n) of HA/PVP blends were calculated by the Ostwald–de Waele equation, indicating a shear-thinning effect in which pseudoplasticity increased with increasing HA contents. Mechanical properties, such as tensile strength and elongation at the break, were higher for HA/PVP films with wHA = 0.5 compared to those with higher HA contents. The elongation at the break of HA/PVP blend films displayed a pronounced increase compared to HA films. Moreover, infrared analysis confirmed the existence of interactions between HA and PVP. The blending of HA with PVP generated films with elasticity and better properties than homopolymer films.

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The influence of the molecular mass of two incompatible polymers on their miscibility in the solid state without compatibilizer after casting from solution

Cited by 17 publications

References 9 publications

A Comparative Experimental and Theoretical Study between Heteroarm Star and Diblock Copolymers in the Microphase Separated State

A Comparative Experimental and Theoretical Study between Heteroarm Star and Diblock Copolymers in the Microphase Separated State

Phase behavior of ternary blends containing dimethylpolycarbonate, tetramethylpolycarbonate and poly[styrene‐co‐(methyl methacrylate)] copolymers (or polystyrene)

Characterisation of Hyaluronic Acid Blends Modified by Poly(N-Vinylpyrrolidone)

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