Segmental miscibility

The torsional measurements show only one maximum on the damping curve. This means that there is a good segmental miscibility between the networks in the UPR-BPA/DC system. 

As has already been stated, the verified possibility of extending the reduced variables principles to ABS resins makes it possible to treat these typical heterophase systems as blends of amorphous homophase polymers and plasticizers. One possible explanation is that over the experimental y range it is not possible to separate the contributions of the two different phases, and the materials will behave as homophase polymer. In fact, long-time molten polymer rheology experiments measure viscoelastic processes over the entire molecule, and, as a consequence, molecular compatibility is evaluated (13). On the other hand, high frequency and/or low temperature tests involve the main chain as well as the side chains of the polymer system the segmental miscibility of the polymer-polymer system is then evaluated. It is important in experimental measurements of polymer compatibility to evaluate the actual size of the volume subject to the test. 

Segmental miscibility between the components, even when they are phase separated, imparting a low interfacial tension and an... 

Suitable block and graft copolymers can be used as compatibilizers for polymer blends. A suitable block or graft copolymer contains a segment miscible with one blend component and another segment with the other blend component. The copolymer segments are not... 

A rigorous definition of miscibility is used in the following tables. In order to be classified as miscible polymers, there must be some evidence in the literature that the polymers are miscible on a submolecular (segmental) scale. If the polymer mixture contains several phases, the polymers will be listed as miscible even if segmental miscibility data... 

DMPPO and polystyrene form compatible blends. The two components are miscible in all proportions (59). Reported dynamic—mechanical results that indicate the presence of two phases in some blends apparendy are caused by incomplete mixing (60). Transition behavior of thoroughly mixed blends indicates that the polymers are truly compatible on a segmental level (61). CompatibiUty may be attributed to a %— % interaction between the aromatic rings of the two polymers sufficient to produce a negative heat of mixing. However, the forces are very small, ie, = ca40 J/mol (9.6 cal/g), and any... 

Another important feature of some random copolymers is the abihty to achieve miscibility in either a homopolymer or a second random copolymer. This "copolymer effect" has been shown empirically for quite some time, eg, PVC is miscible with random copolymers of ethylene and vinyl acetate (52). Such systems are effective because repulsions between the dissimilar segments in the copolymer are enough to overcome the repulsions between these segments and those of the second component in the mixture. In other words, in the above example, the ethylene units "hate" vinyl acetate units more than either of them "hate" PVC. Thus there is a net negative interaction energy and the two materials are miscible (53). 

In many respects, the coupling of GC columns is well suited since experimentally there are few limitations and all analytes may be considered miscible. There are, however, a very wide variety of modes in which columns may be utilized in what may be described as a two-dimensional manner. What is common to all processes is that segments or bands of eluent from a first separation are directed into a secondary column of differing stationary phase selectivity. The key differences of the method lie in the mechanisms by which the outflow from the primary column is interfaced to the secondary column or columns. 

Govindan CK (2002) An improved process for the preparation of benzyl-n-vinyl carbamate. Org Process Res Dev 6 74-77 Gunther A, Jensen KF (2006) Multiphase microfluidics from flow characteristics to chemical and materials synthesis. Lab Chip 6 1487-1503 Gunther A, Jhunjhunwala M, Thalmann M, Schmidt MA, Jensen KF (2005) Micromixing of miscible liquids in segmented gas liquid flow. Langmuir 21 1547-1555... 

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