Poly morphology development

W. Keawwattana, Phase behavior, crystallization, and morphological development in blends of polypropylene (PP) isomers and poly(ethylene-octene) copolymer, Ph.D. Dissertation, The University of Akron, Akron, OH, 2002. 

Y. S. Kim, L. Dong, M. A. Hickner, B. S. Pivovar, and J. E. McGrath. Processing induced morphological development in hydrated sulfonated poly(arylene ether sulfone) copolymer membranes. Polymer, 44(19) 5729-5736, September 2003. 

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.)... 

Marie et al. (2001) have studied PA blends with poly(dimethylsiloxane) (PDMS) either in binary blends of the functionalized polymers or in ternary blends with a functionalized styrene copolymer. The efficiency of copolymer formation concurrent with morphology development and stabilization was studied for reactions between PA-amine and PDMS-anhydride, between PA-amine and PDMS-epoxy, and between PA-carboxylic acid and PDMS-epoxy. The effects of relative melt viscosities on interfacial reactivity and resulting morphology were noted. 

M.F. Li, R. Xiao, G. Sun, Morphology development and size control of poly(trimethy-lene terephthalate) nanoflbers prepared from poly(trimethylene terephthalate)/cellulose acetate butyrate in situ fibrillar composites. Journal of Materials Science 46 (13) (2011) 4524 531. 

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. 

SEM photomicrograph of the smoothed and toluene-etched surfece of a PET ultra-low-density polyethylene (ULDPE)-g-DEM blend obtained in a discontinuous mixer by adding Ti(OBu)4 as a transesterification catalyst. (From M. B. ColtelH, Catalysed Reactive Compatibilization of Polyolefin and Poly(ethylene terephthalate) Blends Reactions Mechanisms and Phase Morphology Development, Ph.D. thesis. University of Pisa, Italy, 2005.)... 

A different approach was taken by Touhsaent et al. [2081. These authors synthesized two polymers, one of which formed a network, by simultaneous independent reactions in the same container. They have indicated that intercrosslinking reactions are eliminated by combining free radical (acrylate) and condensation (epoxy) polymerization. By this method, they modified an epoxy resin with poly(n-butyl acrylate) polymer. They have found that a two-phase morphology developed, consisting of co-continuous rubber domains (about 0.1—0.5 p-m) within the epoxy resin. The dimensions of the dispersed rubber phase domains and the extent of molecular mixing between the two components were found to depend on the relative reaction rates (or gel time) with respect to the rate of phase separation. Better mechanical properties resulted when the extent of molecular mixing was minimized and heterophase semi-IPNs were produced. 

As described above in the section on morphology development, there are several separate mechanisms responsible for the effects of the interfacial reaction on the final morphology. Empirical means may be used to separate some of these simultaneous effects. For example, Scott and Macosko [41] successfully separated the effects of increased mixing torque and changing component rheologies as a fimction of temperature from other effects of the chemical reaction. They utilized Wu s [55] empirical equation for rubber particle diameters in reactive blends with polyamide 66 and poly(ethylene terephthalate) prepared in twin screw extruders ... 

X. D. Lin, W, L. Cheung (2003) Study of poly(ethylene terephthalate)/polypropylene microfibrillar composites, I. Morphological development in melt extrusion, J. AppL Polym, Sci. 89,1743. 

Schultz JM, Miles MJ. AFM study of morphological development during the melt-crystallization of poly(ethylene oxide). J Polym Sci Polym Phys Ed 1998 36 2311-2325. 

Potente H, Bastian M, Gehring A, Stephan M, Potschke P. Experimental investigation of the morphology development of poly-hlends in corotating twin-screw extruders. J Appl Polym Sci 2000 76 708. 

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