Morphology linear polymers

Sorption curves obtained at activity and temperature conditions which have been experienced to be not able to alter the polymer morphology during the test, i.e. a = 0.60 and T = 75 °C, for as cast (A) and for samples previously equilibrated in more severe conditions, a = 0.99 and T = 75 °C (B), are shown in Fig. 13. According to the previous discussion, the diffusion coefficient, calculated by using the time at the intersection points between the initial linear behaviour and the equilibrium asymptote (a and b), for the damaged sample is lower than that of the undamaged one, since b > a. The morphological modification which increases the apparent solubility lowers, in fact, the effective diffusion coefficient. 

Polymer Morphology Cyclic Linear Majority component / P Ref. 

The solution properties of dendrigraft polybutadienes are, as in the previous cases discussed, consistent with a hard sphere morphology. The intrinsic viscosity of arborescent-poly(butadienes) levels off for the G1 and G2 polymers. Additionally, the ratio of the radius of gyration in solution (Rg) to the hydrodynamic radius (Rb) of the molecules decreases from RJRb = 1.4 to 0.8 from G1 to G2. For linear polymer chains with a coiled conformation in solution, a ratio RJRb = 1.48-1.50 is expected. For rigid spheres, in comparison, a limiting value RJRb = 0.775 is predicted. 

Patel N (1990) Multicomponent network and linear polymer system Thermal and morphological characterization. PhD dissertation, URL + S.U. (under MacGrath JE)... 

Siebert and Riew (4) described the chemistry of the in situ particle formation. They proposed that the composition of the particle is a mixture of linear CTBN-epoxy copolymers and crosslinked epoxy resin. The polymer morphology of the CTBN toughened epoxy systems was investigated by Rowe (5) using transmission electron microscopy by carbon replication of fracture surfaces. Riew and Smith (6) supported the... 

Lee et al. demonstrated the synthesis of nanostructured cubic polymer gels by copolymerization of dienyl substituted lipids [66]. No phase transitions, or changes in dimensions, were observed with temperature changes for the polymerized sample. Furthermore, the polydomain square lattice of the gel was visualized by TEM of ultramicrotomed samples after extraction of the template (Fig. 7). In contrast, copolymerization of monoacylglycerol and 1,2-diacylglyc-erol in a cubic lyotropic state did not result in a continuous gel structure. Linear polymer chains were obtained instead, and the cubic morphology was destroyed by addition of organic solvent [67]. Similar polymerizations in the inverted... 

Fig. 2.20 Examples of electron micrographs of polymers, (a) A defocussed bright-field image of a thin film of isotactic polystyrene annealed and crystallised at about 170 °C (b) An image of a fracture surface replica from a sample of linear polyethylene crystallised from the melt at 4.95 kbar. ((a) Adapted by permission of Masaki Tsuji and (b) adapted from Principles of Polymer Morphology by D. C. Bassett. Cambridge University Press 1981.)...

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