Phase diagrams of blends

For most of the results discussed below, the following is valid concerning COP, PC and mixtures if not otherwise stated. The thermotropic copolyester derived from p-hydroxybenzoate and poly(ethylene terephthalate) [10] containing 60 mol% PHB was used exclusively as the PLC component because this composition has the best mechanical properties [10,118] of these copolymers. It was obtained from Eastman Kodak, Kingsport, TN, and had an average molar mass estimated from solvent viscosity of about 19000 g mol . The sequence distribution was calculated from C-NMR as described by Lenz et al. [119] and was nearly random the statistical parameter which describes the randomness of the copolymer is = 1 for a block copolymer and P = 0 for a completely random copolymer. The copolymer used for the experiments had P = 0.15. 

Polycarbonate from bisphenol-A served as the EP. It was obtained from the Bayer A.G., Leverkusen, Germany. The number-average molar mass was determined by vapor pressure osmosis = 18700gmol . The mass average was estimated by 

The diagram is very complex with at least 17 phases. The main reason is the fact that the pure COP already shows a multiphase behavior [50]. According to Yoon and coworkers [105] there are two mesophases in the pure COP, SmE and SmB, which might also be observable in the blend. However, in the liquid state, especially at temperatures higher than 260 C, transesterification and/or degradation processes are observable, so that all phases claimed in this area are in some sense hypothetical because they could not be observed unequivocally due to the reasons outlined above, although their existence can be predicted from theoretical arguments. 

At about 50% (w/w), phase inversion takes place, and at COP concentrations beyond 50% the formation of LC-rich islands in an LC-poor matrix is observed. These islands have been described by several authors in the COP system [118] and in a blend consisting of a rigid rod and a semiflexible coil polymer [121]. The formation of these islands is mainly due to differences in viscosity and surface tension of LC-poor and LC-rich phases and the tendency to achieve efficient packing by orientation and the lowering of lateral distances of the anisotropic parts of a polymer. The LC-poor (= PC-rich) matrix has a higher melt viscosity than that of COP. In a shear field or under 

P PET glass PHB islands PHB crystals PC glass PC crystals PET/PC glass 

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Fig. 56 Phase diagram of blend of PS-fi-PI with PS. T0dt. o TDMt, Toot- Vertical lines separating microdomain structures are obtained from total volume fraction PS in system. Dashed line results of mean-field calculation for ODT. The OOT line which exists at volume fractions ps 5 ub was obtained during a heating process. From [174]. Copyright 2000 American Chemical Society...

Fig. 61 a Schematic representation of phase diagram of blend of PS-rich (a) with Pi-rich (/S) PS-fc-PI block copolymer in parameter space of a, and T. Expected morphologies of blend specimen are also sketched at b low and c high temperatures. Note phase diagram is effective only for American Chemical Society... 

Figure 15. Proposed phase diagram of blends of amino terminated PIP and carboxylic acid or sulfonic acid terminated PMS. ...

Evolution of Phase Diagrams. The increase in the molar mass of the cyanate ester with conversion obviously modifies the phase diagram of blends. The evolution of phase diagrams of nonfunctional rubber was first studied. 

Morphological Phase Diagrams of Blends of Polypropylene Isomers with Poly(Ethylene-Octene) Copolymer... 

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