Immiscible blends polymer blend

Miscible polymer blend polymer blend, homogenous down to the molecular level, in which the domain size is comparable to the macromolecular dimension associated with negative value of the free energy of mixing, AG Aff , < 0, and within the phase stability condition cP hGmld > 0 Immiscible blends polymer blends whose free energy increases upon mixing, i.e., AG , ci... 

Other models are based upon the immiscibility of polymer blends described above, and they model the system as Newtonian drops of the dispersed polymer with concentration (pi in a Newtonian medium of the second polymer with concentration (p2 = — (pi. There exists some concentration, cpu = cp2i — 1, at which phase inversion takes place that is, at snfficiently high concentration, the droplet phase suddenly becomes continuous, and the second phase forms droplets. The phase inversion concentration has been shown to correlate with the viscosity ratio, A. = r i/r 2, and the intrinsic viscosity for at least a dozen polymer alloys and blends ... 

Immiscible, compatibilized polymer blend with modified interface and morphology. 

The immiscible semicrystalline polymer blends may be classified in terms of crystalline/crystalline systems in which both components are crystalliz-able, and crystalline/amorphous systems in which... 

Immiscibility dominates polymer blends. It reveals itself as opacity, delamination, double... 

Karasz and McKnight (1977) have developed a model based on segmental interaction parameters in copolymers to quantify these qualitative interactions. Each segment in a copolymer conriibutes to both a configurational and an enthalpic term due to chemical interaction. A pair of copolymers can be miscible or immiscible, or a single polymer can act as a compatibilizer, or an immiscible blend polymer can act as a compatibilizer. Paul and Barlow have shown that A H may be negative in a blend due to dilution of more unfavorable interactions, where at least one component in the blend is a copolymer (Paul and Barlow, 1980). 

Morphology of the uncompatibilized (a, a a") and compatibilized (b, b b") ternary poly-propylene/polystyrene/polyamide (PP/PS/PA6) (70/15/15) blends (a,b) cryofractured surface, (a, b ) cryofractured and PS phase extracted using tetrahydrofuran (THF), (a", b") cryofractured and PA6 phase extracted using HCOOH. (Reproduced from Wang, D., Li, Y., Xie, X.-M., and Guo, B.-H. 2011. Compatibilization and morphology development of immiscible ternary polymer blends. Polymer 52 191-200 with permission from Elsevier.)... 

Patlazhan et al. [11] studied the shear-induced fractal morphology of immiscible reactive polymer blends. The example of grafting and cross-linking multilayer systems of statistic terpolymer of ethylene, butyl acrylate, and maleic anhydride (MAH) and statistic copolymers (CPA) including... 

Ratlazhan, S., Schlatter, G., Serra, C., Bouquey, M., and Muller, R. 2006. Shear-induced fractal morphology of immiscible reactive polymer blends. Polymer 47 6099-6106. 

The blending of polymers offers the opportunity to create materials with modified properties such as impact strength or rigidity without the necessity to synthesize a new polymer. However, because of entropic constraints, most polymer combinations are immiscible. A polymer blend can be produced by a non-reactive or reactive route. 

The immiscible semicrystalline polymer blends may be classified in terms of crystalline/crystalline systems in which both components are crystallizable and crystalline/amorphous systems in which only one component can crystallize, being either the matrix or the dispersed phase (Utracki 1989). Numerous authors have been investigating the crystallization behavior of immiscible blends. In Tables 3.14 and 3.15, an overview is given of a number of important immiscible crystallizable blend systems. 

Immiscibility dominates polymer blends. It reveals itself as opacity, delamination, double glass transition, or combination of these properties. Most immiscible polymer blends require compatibilization and toughening. 

Gleisner, W., Braun, H., Friedrich, Chr., and Cantow, H.-J. (1994) Correlation between rheology and morphology of compatibilized immiscible blends. Polymer, 35 (2), 128-135. 

Bitinis et developed for the first time a novel and industrially scalable PLA-NR blend prepared by melt mixing blends at 5,10 and 20 wt% of natural rubber to analyze the effect of the NR concentration on the blend morphology. Figure 7.5 shows SEM micrographs of the blends fracture surfaces where it is observed that the size of the rubber particles is similar for 5 and 10 wt% but increases for the blend at 20 wt% from 1.15 to 2.00 pm. In general, in an immiscible binary polymer blend, the size of the dispersed phase increases as a function of the concentration of the minor phase in the blend, due to coalescence phenomena. ... 

For the immiscible blended polymer type, phase-separated mixtures are obtained when one tries to mix most polymers. However, strangely enough, the phase-separated materials also turn out to be sometimes useful. The examples of immiscible polymer are polystyrene and polybutadiene. When polystyrene is mixed with a small amount of polybutadiene, the two polymers do not blend. Polybutadiene separates from the polystyrene into Uttle spherical blobs. 

Li M F, Xiao R and Sun G (2011) Formation and morphology development of poly(butylene terephthalate) nanofibers from poly(butylene terephthalate)/cellulose acetate butyrate immiscible blends, Polym Eng Sci 51 835-842. 

Grizzuti Nino, Buonocore Giovanna Giuliana, and lorio Giulia. Viscous behavior and mixing rules for an immiscible model polymer blends. J. Rheol. 44 no. 1 (2000) 149-164. 

Iza Mustapha, Bousmina Mosto, and Jerome Robert. Rheology of compatibilized immiscible viscoelastic polymer blends. Rheol. Acta. 40 no. 1 (1999) 10-22. 

R. Ratnagiri and C. E. Scott, Effect of Viscosity Variation with Temperature on the Compounding Behavior of Immiscible Blends, Polym. Eng. Sci. 39(9), 1823-1835 (1999). 

A. Leclair, B. D. Favis (1996) The role of interfacial contact in immiscible binary polymer blends and its influence on mechanical properties. Polymer 37,4723. ... 

In the present chapter, the morphology development of immiscible binary polymer blends is discussed. First, morphology development in droplet-matrix structures is described. Subsequently, the dynamics of fibrillar structures is reviewed and finally cocontinuous structures are briefly discussed. Although the main aspects of polymer blending are well established and polymer blends are already widely used in commercial products, recent novel insights in the areas of miniaturization and particle stabilization have opened new research topics in the area of polymer blending. In the last part of this chapter, these recent advances in polymer blend systems are briefly discussed. 

The phase morphology of immiscible ternary polymer blends was the object of a review of Shokohooi et al. [12], According to the generalized Harkins equation, in a ternary A/B/C blend, the spreading coefficient, Aqb, is defined as the parameter showing the tendency of component C to encapsulate component B in a matrix of component A and is related to the interfacial tension of the components in the following manner ... 

Phase Morphology in Immiscible Binary Polymer Blends... 

Here we are concerned with adding a third component to an immiscible binary polymer blend in which the third component consists of amphiphilic molecules with different sections that interact differently with the two polymer phases. Of special interest is the case where one section of this molecule has a strong interaction or miscibility in one of the phases and the other has similar interactions with the second polymer phase. 

In conclusion, cocrystallization, even partial, seems to be an attractive approach to overcome the immiscibility in polymer blends, and it can be apphed to both condensation polymers and polyolefins having a common crystallizable component. 

Grizzuti, N., G. Buonocore, and G. Lorio. 2000. Viscous Behavior and Mixing Rules for an Immiscible Model Polymer Blend. J. RheoL, 44(1), 149-164. 

Dual glass transition behavior is observed in immiscible binary polymer blends or block copolymers which have undergtme microphase separation to create discrete domains of each type of polymer in the rrratrix. The itaconate structures considered here are comb-branch polymers with relatively short side chains which plasticize the polymer efficiently when the chain lengdis are Cj to Cfy but then undergo a subtle change in bdiavior at long chain lengths. While there is no apparent... 

Jorda, R. and Wilkes, G.L. (1988) A novel use of physical aging to distinguish immiscibility in polymer blends. Pdym. BuU., 20, 479. 

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