Covalent macromolecules

In the polymerization of THE, the kinetics and thermodynamics of the equilibrium between covalent macromolecules (macroesters) and macroion pairs have recently been elucidated e.g. for CF3SOJ anion ... 

The polymerization of 2-methyl-2-oxazoline is another example of the parallel growth of macroions and covalent macromolecules X The averaged rate coefficients of propagation kp (including kj, and k ) for various anions, namely Cl , Br ,, and OTos (Tos = S02C H4CH3-p) were measured in CD3CN at 40 °C and found to be equal to (x 10, in mole 1 s ) 0.03,... 

The Rate of Interconversion of Covalent Macromolecules and Macroion Pairs... 

The graieral scheme of polymerization of a heterocyclic monomer involving temporary t mination includes a number of diffraent species covalent macromolecules, macroion pairs and macroions ... 

Biotin (Fig. 4.5) is involved in the strongest known non-covalent macromolecule-ligand interaction. In fact, given the small size of biotin, it is surprising to many that this association is so strong (Ka corresponding to... 

Ross and Subramanian [21] have suggested, on the basis of analysis of AH and 45 of protein-Ugand interactions, that a negative AH for association could come from enhanced polar interactions in the relatively lower dielectric medium of the protein (compared to water). Thus, even though such interactions are clearly less important than for gas phase association, they may contribute along with dispersion to non-covalent macromolecule hgand association. 

The bonds between atoms in the backbone, or main chain, do not necessarily have to be covalent. Macromolecules may have coordinate bonds... 

Around 1910-1920, all facts strongly supported the theory that organic colloids were physical groups of particles and not true covalent macromolecules. Organic colloids had the same overall composition and reactivity as their known noncolloidal basic components. Furthermore, they could often be converted back to the noncolloidal material and were not crystal-lizable. Anomalies appeared during molar mass determinations. 

The success of the above-described synthetic protocol can be judged by a single fact that, in passing from the G4 to the G5 polymer, almost 170000 reactions were carried out on a single polymer chain. To date, the G5 polymer is the largest covalent macromolecule of defined chemical structure to have been synthesized, with lengths in the range of a few microns and a diameter of approximately... 

As in the case of covalent macromolecules, the supramolecular associations may also present internal (intrasupramolecular) interactions between sites located either in the main-chain or in side-chain appendages, thus leading to chain folding and structuration of the supramolecular entity. 

Fig. 6 (a-i) Topologies of supramolecular and covalent macromolecules dendronized with self-assembling dendrons, twin dendrons, and Janus dendrimeis. Reprinted with permission from... 

The present volume follows the initial study A Prehistory of Polymer Science [1]. The origins and development of the field were surveyed up to the time of the Faraday Discussion of 1935 on Polymerization. From early studies of caoutchouc at the French Academy of Sciences to seminal syntheses of polyamides at DuPont, the concept of covalent macromolecules was developed. This fruitful concept was extended to a large number of observable properties in the period 1935-1953. 

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