Blended polymers morphological effects

Another example of static SIMS used in a more quantitative role is in the analysis of extmded polymer blends. The morphology of blended polymers processed by extrusion or molding can be affected by the melt temperature, and pressure, etc. The surface morphology can have an effect on the properties of the molded polymer. Adhesion, mechanical properties, and physical appearance are just a few properties affected by processing conditions. 

Hong, B. K. and Jo, W. H. (2000) Effects of molecular weight of SEBS triblock copolymer on the morphology, impact strength, and rheological property of syndiotactic polystyrene/ ethylene-propylene rubber blends. Polymer, 41, 2069-2079. 

The formation of migration paths of dispersed particles as shown in Fig. 9 suggests a new approach for the modulation of polymer blends and morphology. It is expected that ER or MR effects show not only smartness but also unique anisotropy therefore, many workers are studying these effects from the point of view of polymer processing. 

At the recent European Symposium on Polymer Blends [59] about half of the contributions dealt with thermodynamic effects on molecular architecture, on polymer morphology, and on processing and performance of polymer blend materials. Although some attention has been focused mainly on the interface (material) in heterogeneous blends, in general most thermodynamic studies of such heterogeneous blends deal with two- or more bulk phases. Essential morphological features such as droplet size, cocontinuous phases, micellar or... 

Sanchez-Solis, A. Estrada, M.R. Cruz, J. Manero, O. On the properties and processing of polyethylene terephthalate/styrene-butadiene rubber blend. Polym. Eng. Sci. 2000,40 (5), 1216-1225. Luzinov, I. Xi, K. Pagnoulle, C. Huynh-Ba, G. Jerome, R. Composition effect on the core-shell morphology and mechanical properties of ternary polystyrene/styrene butadiene rubber polyethylene blends. Polymer 1999, 40 (10), 2511-2520. 

Kim HC, Nam KH, Jo WH. The effect of a styrene-methyl methacrylate block copolymer on the morphological, rheological and mechanical properties of poly(2-6-dimethyl-l,4-phenylene ether) (PPE) and poly(hydroxyether of bis-phenol A) (phenoxy) blends. Polymer 1993 34 4043-4051. 

Mariani, P.D.S.C., Allganer, K., Oliveira, F.B., Cardoso, E.J.B.N., Irmocentini-Mei, L.H. Effect of soy protein isolate on the thermal, mechanical and morphological properties of poly (epsilon-caprolactone) and com starch blends. Polym. Testing 28(8), 824—829 (2009) Fornes, T.D., Yoon, P.J., Keskkula, H., Paul, D.R. Nylon 6 nanocomposites the effect of matrix molecular weight Polymer 42(25), 09929-09940 (2001)... 

Thitithammawong, A., Nakason, C., Sahakaro, K., Noordermer., J. (2007). Effect of different type of peroxide on rheological, mechanical, and morphological properties of thermoplastic based vulcanizates based on natural rubber/ polypropylene blends. Polym, Test, 26, 537-546... 

Cui, L., Ding, Y., Li, X., Wang, Z., Han, Y. Solvent and polymer concentration effects on the surface morphology evolution of immiscible polystyrene/poly(methyl methacrylate) blends. Thin Solid Films 515(4), 2038-2048 (2006)... 

Babel A, Li D., Xia Y, and Jenekhe S.A., Electrospun nanofibers of blends of conjugated polymers Morphology, optical properties, and field-effect transistors, Macromolecules, 2005, 38,4705-4711. 

Raman microimaging is used to estimate the effect of the silica filler on phase separation in binary polymer blends composed of BIMS and BR. The domain sizes, relative concentration of polymer components within domains, and distribution of particulate silica filler and zinc stearate curative are characterised for blends of different compositions and history of ageing treatments. The presence of increased concentrations of precipitated silica results in better polymer morphology since domain sizes are reduced. Increased temperature treatment also decreases domain sizes up to about 150 deg.C, but treatment at 200 deg.C appears to induce separation of the elastomer components. Silica is usually found near the centres of the BIMS domains. There is little difference in silica distribution before and after curing. 6 refs. 

Chiu FC, Ung MH (2007) Thermal properties rmd phase morphology of melt-mixed poly (trimethylene terephthalate)/polycarbonate blends-mixing time effect. Polym Test 26 338-350 Chuah HH (2004) Effect of process variables on bulk development of air-textured poly (trimethylene terephthalate) bulk continuous filament. J Appl Polym Sci 92 1011-1017 Chuah HH, Lin VD, Soni U (2001) PTT molecular weight and Mark-Houwink equation. Polymer 42 7137-7139... 

Lee, S. H., Kontopoulou, M., and Park, C. B. 2010. Effect of nanosilica on the co-continuous morphology of polypropylene/polyolefin elastomer blends. Polymer 51 1147-1155. 

Wilkinson, A. N., Clemens, M. L., and Harding, V. M. 2004. The effects of SEBS-g-maleic anhydride reaction on the morphology and properties of polypropylene/PA6/SEBS ternary blends. Polymer 45 5239-5249. 

Although miscible blends of polymers exist, most blends of high-molecular-weight polymers exist as two-phase materials. Control of the morphology of these two-phase systems is critical to achieve the desired properties. A variety of morphologies exisL such as dispersed spheres of one polymer in another, lamellar structures, and co-continuous phases. As a resnlL the properties depend in a complex maimer on the types of polymers in the blend, the morphology of the blend, and the effects of processing, which may orient the phases by shear. 

The scientific literature on crystallization in polymer blends clearly indicates that the crystallization behavior and the semicrystalline morphology of a polymer are significantly modified by the presence of the second component even when both phases are physically separated due to their immiscibility. The presence of the second component, either in the molten or solid state, can affect both nucleation and crystal growth of the crystallizing polymer. The effect of blending on the overall crystallization rate is the net combined effect on nucleation and growth. 

This class of polymer was first electrospun by Nair et al. [192] who evaluated the effect of process parameters such as the nature of the solvent, concentration of the polymer solution, effect of needle diameter, and applied potential on the diameter and morphology of poly[bis(p-methylphenoxy)phosphazene fibers. A poly[(amino acid ester)phosphazene] has been electrospun in blend with gelatin [193] to... 

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