Binary Homopolymer Blends

This chapter summarizes the available data (x and / parameters) for polymer-polymer interactions in the melt state. The equations that are necessary to convert x parameters into binary homopolymer blend phase diagrams are also provided. We also summarize methods for predicting the properties of nanostructures with interfaces that are stabilized by the presence of block copolymers. 

A variety of phase behaviors have been observed in binary homopolymer blends. Some blends phase separate on heating while others phase separate on cooling. This depends on whether x increases or decreases with temperature. Blends in which x changes nonmonotonically with temperature exhibit more complex phase diagrams. The... 

The special situation of a homogeneous saddle point, corresponding to a homogeneous disordered phase, is particularly interesting. In that case, ex-phdt analytical relations between the single chain partition function and the fields can be obtained, and one recovers the well-known random phase approximation (RPA). To illustrate this approach, we shall now derive the RPA structure factor for the case of a symmetric binary homopolymer blend. 

We concentrate here on a binary homopolymer blend under constant volume conditions generalizations to ternary or more complex mixtures is straightforward. Substituting the PRISM Eq. (6.2) in Eq. (6.3) yields... 

The sindace composition and near surface gradient structure of miscible binary homopolymer blends are determined by a balance between the surface energy... 

Estridge CE, Jayaraman A Diblock copolymer grafted particles as compatibilizers for immiscible binary homopolymer blends, CS Macro Lett 4 155—159, 2015. 

Schwahn et al. 1995, ginzburg criterion for the mean-field to 3-dimensional ising crossover in polymer blends, Phys. Rev. E, Vol. 52, No. 2, PP. 1288-1291 19%, Temperature and pressure dependence of the order parameter fluctuations, conformational compressibility, and the phase diagram of the PEP-PDMS diblock copolymer. Physical Reuieiv Letters, Vol. 77, No. 15, PP. 3153-3156 2001, Abnormal pressure dependence of the phase boimdaiies in PEE-PDMS and PEP-PDMS binary homopolymer blends and diblock copwlymers. Macromolecules, Vol. 34, No. 6, PP. 1694-1706... 

Equation 24b can similarly be used to generate the /sans parameter for a binary homopolymer blend, say A/C, by replacing subscript B with A and D with C. The resulting expression,... 

For simplicity, we invoke the traditional assumption that the SANS interaction parameters for A/B binary blends and A-b-B diblock copolymer melts are identical. The BLCT Eq. 28d for xsans of an A/B binary homopolymer blend. 

When applied to systems containing statistical copolymers, the SLCT loses its enormous analytical and physical simplicity due to the greater complexity of these systems compared to binary homopolymer blends. The lack of mathematical simplicity in describing copolymer blends arises, in part, from the dependence of the free energy on the monomer sequence. Therefore, a further approximation is introduced into the SLCT to generate a theoretical approach that is simple and easy to use but is devoid of a serious deficiency of the extensions of FH theory to random copolymer systems, namely, the neg-... 

Phase morphologies of immiscible binary homopolymer blends evolve from circular domains of one phase dispersed in the matrix of another through a bicontinuous domain structure to the inverse case of the former [106], When a blend is deposited in thin films, its morphology is also affected by interactions of the polymers constituting the blend with the film interfaces. 

Tsenoglou, C. Viscoelasticity of binary homopolymer blends. AC5 Polym. Prepr. (1987) 8, pp. 185-... 

Binary Homopolymer Blends Random Phase Approximation 340... 

Two examples of binary homopolymer blends exhibiting a crossover from mean-field to 3D-lsing critical behavior will be presented. The first blend is a lower critical solution temperature (LCST) blend of high-molar-volume dPS and PVME at... 

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