Compatible polymer blends

Compatible Polymer Blends A term indicating commercially useful materials, mixture of polymers with strong repulsive forces that is homogeneous to the eye. 

Process of modification of the interfacial properties in an immiscible polymer blend that results in formation of the interphases and stabilization of the morphology, leading to the creation of a compatible polymer blend. 

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. 

Glass transition temperature is one of the most important parameters used to determine the application scope of a polymeric material. Properties of PVDF such as modulus, thermal expansion coefficient, dielectric constant and loss, heat capacity, refractive index, and hardness change drastically helow and above the glass transition temperature. A compatible polymer blend has properties intermediate between those of its constituents. The change of glass transition temperature has been a widely used method to study the compatibility of polymer blends. Normally, the glass transition temperatme of a compatible polymer blend can be predicted by the Gordon-Taylor relation ... 

Tg data for the blends are shown in Figure 1. Results obtained by DTA on PMMA-PVdF blends which had been melt extruded and "annealed at room temperature appeared to be anomalous in terms of the theory for glass transition of copolymers or compatible polymer blends (6). These data indicated a limiting value for Tg of ca. 40°-45°C. However, x-ray examination showed that samples with more than ca, 35% PVdF exhibited a crystalline phase, indicating that some of the PVdF had precipitated. When these systems were re-examined by dilatometry... 

Table 3.2 Common Polymer Blends Compatible polymer blends...

The present review is mainly concerned with the preparation and functionalization of micro compositional materials with cellulosic polysaccharides as the principal component, including four major categories graft copolymers, miscible or compatible polymer blends and networks, polysaccharide/inorganic nanohybrids, and mesomorphic ordered systems. Ultrathin layers of cellulosic... 

The viscosity functions of homopolymers and compatible polymer blends measured at different temperatures can be shifted together by displacement along a 45° axis to form a single curve (mastercurve) by time-temperature-superposition (see Fig. 3.12). This... 

D. Schwahn, G. Meier, K. Mortensen, and S. Janssen (1994) On the N-scaling of the ginzburg number and the critical amplitudes in various compatible polymer blends. J. Phys. II (France) 4, pp. 837-848 H. Frielinghaus, D. Schwahn, L. Willner, and T. Springer (1997) Thermal composition fluctuations in binary homopolymer mixtures as a function of pressure and temperature. Physica B 241, pp. 1022-1024... 

Immiscible polymer blend, Compatible polymer blend... 

It is also not the purpose of this chapter to summarize examples of compatible polymer blends formed in a solution step involving dissolution of the polymer components. In some cases such blends are only pseudo-stable , since they may not have been processed above the Tg of one or both of the components. Also, mixing in solution followed by devolatilization is rarely economical for practice in industry, particularly since many commercially important compatibilized polymer blends comprise at least one semicrystalline component e.g., PA) which is poorly soluble in common solvents. There are included in the Tables a small number of examples of solution blended polymer blends when these complement similar examples prepared by melt processing. 

Compatible Polymer Blends. These are immiscible polymer blends that exhibit macroscopically uniform physical properties caused by sufficiently strong interface interactions between the polymer blend components. 

Highly compatible polymer blends of PPE and linear polyester resins provide beneficial improvements in the chemical resistance required for automotive applications. Such automotive applications include molded thermoplastic body panels. Foamable compositions of PPE resins are particularly suited as sources of lightweight structural substitutes for metals, especially in the automotive industry. 

Couchman, P. R., Compositional variation of glass-transition temperatures 2. Application of thermodynamic theory to compatible polymer blends. Macromolecules, 11, 1156-1161... 

Wu, S., Entanglement, friction, and free volume between dissimilar chains in compatible polymer blends, J. Polym. Sci. Polym. Phys., 25, 2511-2529 (1987). 

Polymer blends are expected to create many useful novel materials with specific properties that cannot be achieved by individual polymers in the future. And blending is an easy and inexpensive method of modifying various properties of polymer. A polymer blend or polymer mixture is a kind of material analogous to metal alloys, in which at least two polymers are blended together to create a new material with tailored physical properties, which can be broadly divided into three categories immiscible, compahble, and miscible polymer blends. The immiscible blends are made of two polymers, and two glass transition temperatures will be observed. Compatible polymer blends are immiscible polymer blends that exhibit macroscopically uniform physical properties. The macroscopically uniform properties are usually... 

As Fig. 2 illustrates, the stress at break (or yield) of the compatible Copolymer B blends rises to a maximum at between 60 and 80% PPO. This apparent enhancement in strength has been observed in the case of polymers antiplasticized by low molecular weight additives (14) and suggests that the compatible copolymers act as polymeric antiplasticizers for PPO. This analogy to antiplasticization has been applied to other compatible polymer blends (15,16). Similar synergistic dependence of tensile strength on blend composition for PS/PPO blends has been reported (13,17). In a study of... 

Compatible polymer blends Natural rubber and polybutadiene Polyamides (e.g., PA 6 and PA 66)... 

Compatible polymer blend Term to be avoided At best a utilitarian, nonspecific term indicating a marketable, visibly homogeneous polymer mixture, with enhanced performance over the constituent polymers... 

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