Blends polymer materials

Kairong Liao, Chenmou Zheng, Yongqian Qu. Synthesis of aluminate coupling agents and their modification on PVC/L-CaCOj and PVC/L-CaCOj blends. Polymer Materials Science and Engineering, ll(6) 40-44, 1995. 

The level of technical service support provided for a given product generally tracks in large part where the suppHer considers thek product to be located within the spectmm of commodity to specialty chemicals. Technical service support levels for pure chemicals usually provided in large quantities for specific synthetic or processing needs, eg, ammonia (qv), sulfuric acid (see SuLFURic ACID AND SULFURTRIOXIDe), formaldehyde (qv), oxygen (qv), and so forth, are considerably less than for more complex materials or blends of materials provided for multistep downstream processes. Examples of the latter are many polymers, colorants, flocculants, impact modifiers, associative thickeners, etc. For the former materials, providing specifications of purity and physical properties often comprises the full extent of technical service requked or expected by customers. These materials are termed undifferentiated chemicals (9),... 

In a molded polymer blend, the surface morphology results from variations in composition between the surface and the bulk. Static SIMS was used to semiquan-titatively provide information on the surface chemistry on a polycarbonate (PC)/polybutylene terephthalate (PBT) blend. Samples of pure PC, pure PBT, and PC/PBT blends of known composition were prepared and analyzed using static SIMS. Fn ment peaks characteristic of the PC and PBT materials were identified. By measuring the SIMS intensities of these characteristic peaks from the PC/PBT blends, a typical working curve between secondary ion intensity and polymer blend composition was determined. A static SIMS analysis of the extruded surface of a blended polymer was performed. The peak intensities could then be compared with the known samples in the working curve to provide information about the relative amounts of PC and PBT on the actual surface. 

Following the success in blending rubbery materials into polystyrene, styrene-acrylonitrile and PVC materials to produce tough thermoplastics the concept has been used to produce high-impact PMMA-type moulding compounds. These are two-phase materials in which the glassy phase consists of poly(methyl methacrylate) and the rubbery phase an acrylate polymer, usually poly(butyl acrylate Commercial materials of the type include Diakon MX (ICI), Oroglas... 

Inoue, T. and Marechal, P. (1997) Reactive processing of polymer blends polymer-polymer interface aspects, in Processing of Polymers, ed. Meijer, H.F..H. Materials. Science and Technology, A Comprehensive Treatment, eds. Cahn, R.W., Haasen, P. and Kramer, E.J. (VCH, Weinheim) p. 429. 

Compatibility. Clear definition of compatibility is rather difficult. Compatibility has been defined as the ability of two or more materials to exist in close and permanent association for an indefinite period without phase separation and without adverse effect of one on the other [28]. On the other hand, compatibility is easily recognized in solvent-borne adhesives as a homogeneous blend of materials without phase separation. Normally, compatibility is understood as a clear transparent mixture of a resin with a given polymer. But, compatibility is a more complex thermodynamic phenomenon which can be evaluated from specific... 

Compounding and palletizing of the latex blended material is sometimes done by melt mixing. In such cases precautions must be taken to avoid thermal and shear degradation of the blended polymer. 

Since multiple electrical and optical functionality must be combined in the fabrication of an OLED, many workers have turned to the techniques of molecular self-assembly in order to optimize the microstructure of the materials used. In turn, such approaches necessitate the incorporation of additional chemical functionality into the molecules. For example, the successive dipping of a substrate into solutions of polyanion and polycation leads to the deposition of poly-ionic bilayers [59, 60]. Since the precursor form of PPV is cationic, this is a very appealing way to tailor its properties. Anionic polymers that have been studied include sulfonatcd polystyrene [59] and sulfonatcd polyanilinc 159, 60]. Thermal conversion of the precursor PPV then results in an electroluminescent blended polymer film. 

The properties of polymer materials can e greatly extended by blending two or more homopolymers together. Blends may be classified as compatible or incompatible - although this does depend on the dimensions being considered. Compatibility is influenced by the molecular weight of the homopolymers and is enhanced in practice by incorporation of block copolymers and other compatibilizers. The effects of radiation on blends depend on the degree of compatibility and the extent of inter-molecular interaction (physically and chemically) between the different types of homopolymers. 

Polyvinyl alcohol (PVA), which is a water soluble polyhidroxy polymer, is one of the widely used synthetic polymers for a variety of medical applications [197] because of easy preparation, excellent chemical resistance, and physical properties. [198] But it has poor stability in water because of its highly hydrophilic character. Therefore, to overcome this problem PVA should be insolubilized by copolymerization [43], grafting [199], crosslinking [200], and blending [201], These processes may lead a decrease in the hydrophilic character of PVA. Because of this reason these processes should be carried out in the presence of hydrophilic polymers. Polyfyinyl pyrrolidone), PVP, is one of the hydrophilic, biocompatible polymer and it is used in many biomedical applications [202] and separation processes to increase the hydrophilic character of the blended polymeric materials [203,204], An important factor in the development of new materials based on polymeric blends is the miscibility between the polymers in the mixture, because the degree of miscibility is directly related to the final properties of polymeric blends [205],... 

Karim A, Yurekli K, Meredith C, Amis EJ, Krishnamoorti R (2002) Combinatorial methods for polymer materials science phase behavior of nanocomposite blend films. Polym Eng Sci 42 1836-1840... 

Conducting composite polymer materials have also been prepared from the dispersed phase of concentrated emulsions. Polyurethane/polypyrrole composites [165] were obtained by blending an aqueous suspension of polypyrrole with a HIPE of a chloroform solution of polyurethane in aqueous surfactant... 

New products (e.g., nano-filler materials, modified and blended polymers)... 

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