Crystallizability, defined

Even though the first report about the synthesis of crystallizable ABC triblock copolymers was published in 1978 for PS-fo-PB-fo-PCL copolymers [114], in that work only a preliminary study of the tensile properties was performed, without considering the crystallizability of the materials. It was only 20 years later, when the preparation of these materials was reconsidered and optimized, that triblock copolymers with relatively narrow molecular weight distributions were obtained [115], a requisite which is indispensable for the generation of well-defined morphologies. To illustrate the complexity and richness of semicrystalline ABC triblock copolymers, PS-fc-PB-fc-PCL triblock copolymers have been chosen. These copolymers have been prepared with a wide composition range (with PCL contents from 11 to 77%) and they have been compared with PS-fc-PCL and PB-fo-PCL diblock copolymers [29,98, 115-118]. 

Compound Chlorides of Mercury.—Corrosive sublimate is capable of entering into oombinntion with hydrochloric acid and most of the metallic chlorides, forming well-defined crystallizable salts. Thus, with hydroohloric acid it produces a compound, expressed by Hg Cl, HC1 or Ilg Clj, HO with ohloridc of potassium, Hg Cl, KOI, 2 HO, 2 Hg Cl, KC1, 4 HO, and 4 Hg Cl, KOI, 8 HO,. Soda, lithia, baryta, atrontia, calcia, and magnesia salts react in the same way, as also the chlorides of mangdheso, iron, nickel, and cobalt, all of which produce with the mercurial salt well-defined crystalline oompounde. 

Following the procedure used with JeR (Section 5), po data on these and other polymers were correlated in terms of cM/qMc, with results which are shown in Fig. 8.13. The parallel in behavior between the po and JeR master correlations is unmistakable. Even the relative positions of polymers on the master correlations are similar note for example the data on JeR and p0 for polybutadiene. Published data on relatively narrow distribution polyethylene (210,326) have not been included in Fig. 8.13 because departures from tj0 were too small to define P0 with accuracy. However, estimates of po from the data provided suggest that polyethylene may follow a different pattern than other polymers. Departures from rj0 seem to appear at anomalously low shear rates (326). Aside from tj0 values, viscoelastic data on well characterized crystallizable polymers in the melt state are rather scarce. Although not especially anticipated, it is certainly conceivable that erystallizability confers some unusual features to the flow behavior. 

From a practical point of view the purpose of this study was to increase the crystallizability of the polycarbonate by incorporating in it well-defined amounts of plasticizer. With this modification, crystalline polycarbonate films could be made with a higher modulus of elasticity, and these would extend the usefulness of the polymers as photographic film bases. When this study was completed an article was published by Sears and Darby (16), who made an extensive study of the plasticization of polycarbonate using 50 plasticizers of widely differing types. The crystallization tendency in the presence of plasticizers was recognized by these authors as a problem and was circumvented by quench cooling. 

In this article we have shown how a capillary instability may generate a well-defined characteristic size. The materials that derive are essentially emulsions made of liquid or crystallizable droplets. The monodispersity make it possible to obtain materials with perfectly controlled and reproducible properties, which certainly cannot be achieved in presence of polydisperse emulsions. This is why monodisperse emulsions are not only model systems for fundamental science but also materials with commercial applications. 

E., Probing the ligand binding domain of the GluR2 receptor by proteolysis and deletion mutagenesis defines domain boundaries and yields a crystallizable construct. Protein Sci. 1998, 7, 2623-2630. 

Linear and branched polymer structures were defined in Section 1.6. Branched polymers differ from their linear counterparts in several important aspects. Branches in crystallizable polymers limit the size of ordered domains because... 

The order-disorder interphase was defined as the region of loss of crystalline order. Kumar and Yoon (1991) examined this interface and found that in blends the thickness of this transition zone was essentially independent of the interaction parameter between the two polymers (when Xi2 varied from —1 to —0.005). Following the theoretical predictions, the thickness of this region increases only slightly when stiffer chains are considered. Due to the higher degree of order of segments of the crystallizable component in this zone, the penetration of the amorphous component is limited. The compositional interphase, however, is influenced by the stiffness of both chains and by the interaction parameter (the interfacial thickness varies with the reciprocal of This prediction seems to... 

The crystallizability of the ptdymers also showed significant differences l The electroinitiated polymer showed a diffuse halo in X-ray diffraction initially which sharpened to well defined rings after the polymer was annealed above its melting point, at about 200 The crystallizability of the polymer, as revealed in these experiments, suggests a stereo iedfic control of pol)onerization on the electrode surfaces. The ir spectra of the polymer confirmed that polymerization had indeed taten place through the vinyl groups. 

The different characteristic length scales so defined in a semi-ctystalline polymer or a blend consisting of at least one crystallizable component are thus accessible in X-ray scattering experiments and are probed by varying the scattering angle (SAXS or WAXD) that depends on the available sample to detector distance of the instrumental set-up. 

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