Blend multiphase

Heterogeneous media include filled systems where the filler may or may not be inert to the permeant, block copolymers (where phase separation often occurs) and polymer blends. Multiphase systems occur frequently in industrial practice but, unfortunately, satisfactory theoretical descriptions of their permeation behaviour are not available. 

The world production of plastics in 1995 is projected at 76 million metric tons (mT) with an annual growth rate (AGR) of 3.7%. The expected AGR of PBAs is 12% and that of composites 16%. In 1987, 21% of polymers were used in blends and 29% in composites and filled plastics [56]. If this trend continues, by 1995 all manufactured resins will be used in multiphase polymeric systems. Two factors moderating the tendency are ... 

In multiphase polymeric systems, the properties of the end products do not solely depend on the properties of the pure components, but other various parameters also have a great impact (Fig. 1). In order to emphasize these factors, the following systems are taken into consideration (I) elastomer toughened styrene system, (2) elastomer toughened polycarbonate blends, and (3) direct reactive blend processing. 

Figure 1 Molecular and morphological parameters influencing technological properties of multiphasic polymer blends.

In general, the multiphasic heterogenous nature of the impact grade styrene-based polymers is the root cause of their opaque-turbid nature. In determining the transparency of the blends, size and the size-distribution pattern of the dispersed phase along with the refractive index difference between the continuous and the dispersed phases are two very important criterion [133]. 

L. A. Utracki et al.. Polymer Alloys, Blends and lono-mers An overview in Multiphase Polymers Blends and lonomers (L. A. Utracki and R. A. Weiss, cds.), ACS Symposium Series No. 395, 1-35 (1989). 

Fayt R, Jerome R, Teyssie P (1989) Multiphase polymers Blends and ionomers. In Utracki LA, Weiss RA (eds) ACS Sympos Series 395, Washington, p 38... 

In this section of our review, we shall discuss the morphological aspects and structure-property relationships of a few specific copolymeric systems which we think will represent the general features of siloxane containing multiphase copolymers. More detailed discussions about the properties of each copolymer system may be found in the references cited during our review of the copolymer preparation methods. On the other hand an in-depth discussion of the interesting surface morphology and the resultant surface properties of the siloxane containing copolymers and blends will be provided. 

Instead of the familiar sequence of morphologies, a broad multiphase window centred at relatively high concentrations (ca. 50-70% block copolymer) truncates the ordered lamellar regime. At higher epoxy concentrations wormlike micelles and eventually vesicles at the lowest compositions are observed. Worm-like micelles are found over a broad composition range (Fig. 67). This morphology is rare in block copolymer/homopolymer blends [202] but is commonly encountered in the case of surfactant solutions [203] and mixtures of block copolymers with water and other low molecular weight diluents [204,205]. 

Frensch H, Harnischfeger P, Jungnickel BJ (1989) In Utracky LA, Weiss RA (eds) Multiphase polymers blends and ionomers. ACS symposium series 395. American Chemical Society, Washington. DC, p 101, and references therein... 

Definitions of terms related to polymer blends, composites, and multiphase polymeric materials (lUPAC Recommendations 2004), Pure Appl. Chem. 76, 1985-2007 (2004). Reprinted as Chapter 9, this edition. 

Definitions of terms related to polymer blends, composites, and multiphase polymeric materials... 

It is the intent of this doeument to define the terms most commonly encountered in the field of polymer blends and eomposites. The scope has been limited to mixtures in which the eomponents differ in ehemical composition or molar mass or both and in which the continuous phase is polymeric. Many of the materials described by the term multiphase are two-phase systems that may show a multitude of finely dispersed phase domains. Hence, incidental thermodynamic descriptions are mainly limited to binary mixtures, although they can be and, in the scientific literature, have been generalized to multicomponent mixtures. Crystalline polymers and liquid-crystal polymers have been considered in other documents [1,2] and are not discussed here. 

Note 5 The use of the term "polymer alloy for polymer blend is discouraged, as the former term includes multiphase copolymers but excludes incompatible polymer blends (see Definition 1.3). 

Polymeric material, exhibiting macroscopically uniform physical properties throughout its whole volume, that comprises a compatible polymer blend, a miscible polymer blend, or a multiphase copolymer. 

Definitions of Terms Related to Polymer Blends, Composites, and Multiphase Polymeric Materials (2004), 186... 

Harrats, C., Groeninckx, G., and Thomas, S. 2006. Micro- and Nanostructured Multiphase Polymer Blend Systems. Taylor Francis, Boca Raton, FL. 

It is important to mention that the structure/properties relationships which will be discussed in the following section are valid for many polymer classes and not only for one specific macromolecule. In addition, the properties of polymers are influenced by the morphology of the liquid or solid state. For example, they can be amorphous or crystalline and the crystalline shape can be varied. Multiphase compositions like block copolymers and polymer blends exhibit very often unusual meso- and nano-morphologies. But in contrast to the synthesis of a special chemical structure, the controlled modification of the morphology is mostly much more difficult and results and rules found with one polymer are often not transferable to a second polymer. 

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