Poly electron microscopy study

F. J. Esselink, G. Hadziioannou, Transmission electron microscopy study of the indium/P30T and aluminium/ P30T interfaces (P30T is poly (3-octylthiophene)), Synth. Met., 75, 209-212 (1995). 

The structure and properties PE3-C. T blends with a poly(amino ether) (PAE) resin obtained by direct injection molding have been examined. Although the blends were almost immiscible, electron microscopy studies showed extensive intermixing between the two components. Improved mechanical and barrier properties were achieved for these blends due to the small dispersed particle sizes and their good interfacial adhesion (148). 

One of the systems studied was a polystyrene-b/ocfc-poly(ethylene/propylene) (37300 59700 Mn) copolymer in decane. Electron microscopy studies showed that the micelles formed by the block copolymer were spherical in shape and had a narrow size distribution. Since decane is a selectively bad solvent for polystyrene, the latter component formed the cores of the micelles. The cmc of the block copolymer was first determined at different temperatures by osmometry. Figure 13 shows a plot of n/cRT against c (where c is the concentration of the solution) for T=91A °C. The sigmoidal shape of the curve stems from the influence of concentration on the micelle/unassociated-chain... 

Microscopy. This is a powerful tool for studying visually the distribution of the two phases in the polyblend. One can tell not only the domain size of the dispersed phase but also which polymer forms the dispersed phase from refractive index. A phase contrast light microscope can detect heterogeneity at the 0.2-10 /x level. If the sample can be stained preferentially and sectioned with microtome, then under favorable conditions electron microscopy can show heterogeneity to a very fine scale. In a study of PVC-poly(butadiene-co-acrylonitrile) blend,... 

Gohy et al. studied the solution properties of micelles formed by two polystyrene-frZock-poly(2-vinylpyridine)-block-poly(ethylene oxide) (PS-b-P2VP- -PEO) copolymers in water by dynamic light scattering and transmission electron microscopy [92]. Spherical micelles were observed that consist of a PS core, a P2VP shell and a PEO corona. The characteristic sizes of core, shell and corona were found to depend on the copolymer composition. The micellar size increased at pH<5 due to P2VP block protonation (Fig. 19). 

The study by low-angle X-ray diffraction and electron microscopy of concentrated solutions of the copolymers in preferential solvents for polybutadiene (iso-prene, butadiene) or for poly(a-methyl styrene) (styrene, a-methylstyrene, methyl methacrylate, methylethyl ketone) and of copolymers in the dry state obtained by slow evaporation of the solvent from the mesophases have shown the existence of three types of structure hexagonal, lamellar, and inverse hexagonal depending upon the copolymer composition84,85. The factors governing the structural type and the structural parameters are the same as in the case of polystyrene-polybutadiene copolymers85. ... 

The polymers chosen for the initial stages of our studies were poly-(methyl methacrylate) and polystyrene. There were several reasons for this choice, the most important being (1) well-characterized, low-molecular-weight monodisperse samples of poly(methyl methacrylate) and polystyrene are readily available, or at least relatively easy to synthesize and (2) the poly (methyl methacrylate) /polystyrene system is especially amenable to study by scanning electron microscopy, as we... 

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