Secondary binding forces

Interpolymer complexes possess unique physical and chemical properties which are different from those of the initial components and have found applications in technology, medicine, and other fields (Bekturov and Bimendina, 1981). The unique properties of the complexes arise due to a higher degree of molecular ordering that is a result of secondary binding forces. The resulting secondary structures are dictated primarily by the primary structure (monomer sequence), solvent, and temperature of the system. Interpolymer complexes can be classified based on the nature of the secondary binding forces as ... 

The size, shape, and configuration of the protein molecule are determined not only by its primary structure and composition but also by stearic effects and secondary binding forces such as electrostatic, hydrogen, and hydrophobic bonding. These forces are influenced by the environment of the protein molecule, including such factors as the temperature, pH, and composition of the dispersing medium. 

In the laboratory, double-stranded DNA can be separated into single strands. The process of separating the polynucleotide strands of duplex nucleic acid structures is called de-naturation. Denaturation disrupts the secondary binding forces that hold the strands together. Recall that the second-... 

Between parts of the chains interaction forces are active, the secondary binding forces, which are much smaller than the primary chemical bonds by which the chains are held together. Several kinds of secondary binding forces exist ... 

In these aggregation phenomena, the formation of intermacromolecular complexes is attributed to the fact that macromolecules with complementary binding sites interact with each other almost stoichiometrically in solution due to certain secondary binding forces. In this review, the formation of complementary complexes in synthetic macromolecular systems is mainly discussed. 

Secondary Binding Forces Between Intermacromolecular Complexes... 

Secondary binding forces are mainly classified into Coulomb forces, hydro-gen-bonding forces, van der Waals forces, charge transfer forces, exchange repulsion and hydrophobic interactions (Table 1). Besides these forces, there are other interactions such as ion-dipole and solvophobic interactions. 

Even in macromolecular systems, the secondary binding forces mentioned up to here act in the same manner as in the case of low molecular weight compounds, if one considers secondary bonds individually. However, for all practical purposes, they act at the same time in an extremely complicated manner, concertedly and never separately. Moreover, each active site of the molecule interacts cooperatively with other sites because of the neighboring effect (for details see Sect. 4). Therefore, in intra- and intermacromolecular interaction systems, it is quite difficult to investigate separately the effective secondary binding forces, and it should be noted that the total interaction force might not be the sum of the individual binding forces. 

Studies on the interaction between oppositely charged polyelectrolytes date back to 1896 when Kossel389 precipitated egg albumin with protamine. Since that time extensive studies have been made on pairs of strong polyelectrolytes, pairs of strong and weak polyelectrolytes, pairs of weak polyelectrolytes, as well as on amphoteric complexes. However, the theoretical considerations of intermacromolecular interactions between polyelectrolytes were only based on extremely simplified model systems. However, even in the case of such systems, there are many unsolved problems such as the determination of the local dielectric constant in domains of macromolecular chains, the evaluation of other secondary binding forces, especially hydrophobic interactions, and so on. 

Polymerization of monomers in the presence of polymem which can interact with monomers or newly formed polymers via secondary binding forces is called matrix polymerization (or template polymerization, replica polymerization) (Fig. 52). It is expected that matrix polymerization fundamentally affects the kinetic behavior and/or controls some structural details (for example, molecular weight and its distribution, tactidties, optical isomerism, etc.). However, a variation of structural details seems to be realized only when the geometry of the monomers firmly bound on the matrix polymers, which exhibit a regular arrangement of their structures, can be controlled. 

A more vital application is to discern how reinforcement surface treatments improve adhesion to thermoplastic matrices. Since the nonreactive nature of thermoplastics normally precludes interfacial covalent bond formation, secondary bonding forces, such as London dispersion interactions and Lewis add/base interactions, may play a major role in these drcumstances. These secondary binding forces are subject to surface energetics analysis. 

Macromolecular chains interact with each other through secondary binding forces and form intermacromolecular complexes. The electrochemical behaviors of these complexes composed of electroactive polyviologen were studied and compared with those of component polymer to clarify the specific characteristics of polymer complexes. 

Macromolecular chains, as stated in the previous chapter, may undergo interactions in solution except in the ideal state. In this chapter, the association phenomena of more than two different macromolecular chains in solution caused by secondary binding forces such as electrostatic interactions are discussed. The obtained associates are generally called interpolymer complexes . These complexes are divided into four classes on the basis of their main interaction forces, i.e. (1) polyelectrolyte complexes, (2) hydrogen-bonding complexes, (3) stereocomplexes and (4) charge-transfer complexes. 

The contribution of each secondary binding force cannot be clearly separated... 

In this case, P2 is poly(methacrylic acid) (PMAA) and PI and P3 are the polymers which can interact with PMAA through various kinds of secondary binding forces ... 

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