Linear macromolecules

Many complex systems have been spread on liquid interfaces for a variety of reasons. We begin this chapter with a discussion of the behavior of synthetic polymers at the liquid-air interface. Most of these systems are linear macromolecules however, rigid-rod polymers and more complex structures are of interest for potential optoelectronic applications. Biological macromolecules are spread at the liquid-vapor interface to fabricate sensors and other biomedical devices. In addition, the study of proteins at the air-water interface yields important information on enzymatic recognition, and membrane protein behavior. We touch on other biological systems, namely, phospholipids and cholesterol monolayers. These systems are so widely and routinely studied these days that they were also mentioned in some detail in Chapter IV. The closely related matter of bilayers and vesicles is also briefly addressed. 

The flocculation activity of polymers increases with increasing molecular weight. Linear macromolecules are better flocculents than branched ones with the same total molecular weight. In the future the largest growth of polymer applications is expected to be in waste and water treatment, because of ecological problems. 

Zone 8 plastics now being developed using rigid linear macromolecules rather than crystallization and cross-linking, etc. 

Their ability to achieve a high chromophore density (for example, it is possible to introduce three conjugated chains about a single N-atom core in contrast to the two more normally possible with a linear macromolecule) [84]... 

Transcriptases - catalyzing the translation of information from one linear macromolecule into the structure of the nascent linear macromole. 

The formation of the linear polymer from the cyclic monomer requires a decrease of the free energy. Because usually entropy is lost during polymerization, the main driving force for the ring-opening process is the release of the angular strain upon conversion of the cycles to linear macromolecules. Thus, a majority of three- and four-membered rings can be readily and quantitatively converted into polymers. 

The connection between polymer chemistry and ceramic science is found in the ways in which linear macromolecules can be converted into giant ultrastructure systems, in which the whole solid material comprises one giant molecule. This transformation can be accomplished in two ways—first by the formation of covalent, ionic, or coordinate crosslinks between polymer chains, and second, by the introduction of crystalline order. In the second approach, strong van der Waals forces within the crystalline domains confer rigidity and strength not unlike that found when covalent crosslinks are present. 

Inamura I, Isshiki M, and Araki T. 1989. Solubilization of (3-carotene in water by water-soluble linear macromolecules. Bulletin of the Chemical Society of Japan 62(5) 1671-1673. 

Hiller and Funke obtained easily dissolvable linear macromolecules of PVS by anionic polymerization of 1,4-DVB up to conversions of 80-90% [230,231]. In these experiments very low concentrations of n-butyl lithium (n-BuLi) were used and tetrahydrofuran (THF) as solvent. The reactions were carried out at -78 °C and for 7 min. The contents of pendant vinyl groups in the polymer were determined by infrared spectroscopy, mercury-II-acetate addition and catalytic... 

Microgels can not only be synthesized by polymerization but also by polycondensation or polyaddition [350]. In an early work on crosslinking of single linear macromolecules, it could be shown that if a crosslinking agent, such as terephthal dialdehyde, was added to a very dilute solution of a linear polymer such as polyvinyl alcohol, almost exclusively a intramolecular crosslinking of the individual macromolecules took place [351]. 

Fahey, R. C., The Stereochemistry of Electrophilic Additions to Olefins and Acetylenes, 3, 237. Farina, M., The Stereochemistry of Linear Macromolecules, 17, 1. 

Conformation and Deformation of Linear Macromolecules in Concentrated Solutions and Melts in the Self-Avoiding Random Walks Statistics... 

Medvedevskikh Yu. G. Conformation and deformation of linear macromolecules in concentrated solutions and melts in the self-avoiding random walks statistics (see paper in presented book)... 

---