Bulk properties, block copolymers

Bulk Properties. Block polymers can show mechanical properties in the bulk state that are superior to those that can be achieved with the corresponding homopolymers or random copolymers. This improvement in behavior is made possible by the segregated phase structure in block polymers. Of primary interest have been structures possessing both soft and hard phases. These polymers may range from the thermoplastic elastomers in which the hard phase is dispersed in a soft phase matrix, to toughened (i.e., high impact strength) thermoplastics in which the soft phase is dispersed in a... 

It was the objective of this work to investigate the effect of variation in block architecture (number and the order of the blocks) on the crystallinity level, morphology, the stress-strain and hysteresis behavior of this series of polymers. In addition, the composition ratio of the two block types is expected to play a crucial role in determining the bulk material properties of the block copolymers. This is related to the fact that the mechanical properties of block copolymer are typically influenced more substantially by the behavior of the continuous phase, as will be demonstrated.(1,22)... 

Reversible network structure is the single most important characteristic of a thermoplastic elastomer. This novel property generally arises from the presence of a phase-separated morphology in the bulk material which in turn is dictated by the molecular structure, often of a block copolymer nature. A wide variety of synthetic methods can, in principle, produce endless varieties of thermoplastic elastomers this fact coupled with the advantageous processing characteristics of these materials suggest that the use of thermoplastic elastomers will continue to grow in the 1980 s. 

The use of block copolymers to form a variety of different nanosized periodic patterns continues to be an active area of research. Whether in bulk, thin film, or solution micelle states, block copolymers present seemingly unlimited opportunities for fabricating and patterning nanostructures. The wealth of microstructures and the tunability of structural dimensions make them a favorable choice for scientists in a variety of research fields. As reviewed here, they can function as nano devices themselves, or act as templates or scaffolds for the fabrication of functional nanopatterns composed of almost all types of materials. However, there are still two obvious areas which require more work control of the long-range 3D nanostructure via more user-friendly processes and the identification of new materials with different functional properties. 

More specifically, the use of well-designed block copolymers can lead to a fine-tuning of golymeric mate-EiSiS S2EEl22l2SZ obviously a key-point in devising their final (bulk) physical properties. Among the spectacular consequences of such a capability, suffice it to recall ... 

In this chapter, the focus is largely on experimental and theoretical studies of micellization in a range of solutions of model block copolymers prepared by anionic polymerization. A discussion of both neutral and ionic block copolymers is included, and features specific to the latter type are detailed. The adsorption of block copolymers at the liquid interface is also considered in this chapter. Recent experiments on copolymer monolayers absorbed at liquid-air and liquid-liquid interfaces are summarized, and recent observations of surface micelles outlined. Thus this chapter is concerned both with bulk micellization and the surface properties of dilute copolymer solutions. 

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