Synthetic copolymers

This article reviews the preparation, properties, characterization, use, economic importance, and future of some of the important synthetic copolymers. Polymer blends (qv) and composites (qv) are also mentioned. Biocopolymers are not included. 

As has been shown in Ref. [49], the character of bonding of Hb by other macro- and heteroreticular carboxylic CP reflects the structural and electrochemical features of synthetic copolymers. 

Liu, F.-T., Zinnecker, M., Hamaoka, T., and Katz, D.H. (1979) New procedures for preparation and isolation of conjugates of proteins and a synthetic copolymer of D-amino acids and immunochemical characterization of such conjugates. Biochemistry 18, 690-697. 

Khokhlov AR, Ivanov VA, Shusharina NP, Khalatur PG (1998) Engineering of synthetic copolymers protein-like copolymers. In Yonezawa F, Tsuji K, Kaij K, Doi M, Fujiwara T (eds) The physics of complex liquids. World Scientific, Singapore, p 155... 

For many synthetic copolymers, it becomes possible to calculate all desired statistical characteristics of their primary structure, provided the sequence is described by a Markov chain. Although stochastic process 31 in the case of proteinlike copolymers is not a Markov chain, an exhaustive statistic description of their chemical structure can be performed by means of an auxiliary stochastic process 3iib whose states correspond to labeled monomeric units. As a label for unit M , it was suggested [23] to use its distance r from the center of the globule. The state of this stationary stochastic process 31 is a pair of numbers, (a, r), the first of which belongs to a discrete set while the second one corresponds to a continuous set. Stochastic process ib is remarkable for being stationary and Markovian. The probability of the transition from state a, r ) to state (/i, r") for the process of conventional movement along a heteropolymer macromolecule is described by the matrix-function of transition intensities... 

The molecular weight (M 10,200,000) represents the highest molecular weight known to date for a linear, synthetic copolymer. DFT calculations suggest that steric congestion, derived from the triethylsilyl group and the amine moiety, near the polymerization reaction center diminishes the rates of chain termination or transfer processes yet permits the monomer access to the active site and the monomer s insertion into the metal-carbon bond (Fig. 21). 

Li F, Griffith M, Li Z, Tanodekaew S, Sheardown H, Hakim M, Carlsson DJ. Recruitment of multiple cell lines by collagen-synthetic copolymer matrices in corneal regeneration. Biomaterials 26 3093-3104 (2005). 

Lutz JF, Thunemann AF, Rurack K. DNA-like melting of adenine- and th3miine-functionalized synthetic copolymers. Macromolecules 2005 38 8124-8126. 

Inagaki, H., in Fractionation of Synthetic Copolymers , Tung, L. H. (ed), Chapter 8, Marcel Dekker, New York 1977... 

Although recent years have witnessed an impressive confluence of experiments and statistical theories, presently there is no comprehensive understanding of the interrelation between chemical sequences in synthetic copolymers and the conditions of synthesis. One has merely to glance at recent literature in polymer science and biophysics to realize that the problem of sequence-property relationship is by no means entirely solved. As always, in these circumstances, an alternative to analytical theories is computer simulations, which are designed to obtain a numerical answer without knowledge of an analytical solution. 

Thus, copolymers of the same composition can have qualitatively different sequence distributions depending on the solvent in which the chemical transformation is performed. In a solvent selectively poor for modifying agent, hydrophobically-modified copolymers were found to have the sequence distribution with LRCs, whereas in a nonselective (good) solvent, the reaction always leads to the formation of random (Bernoullian) copolymers [52]. In the former case, the chemical microstructure cannot be described by any Markov process, contrary to the majority of conventional synthetic copolymers [ 10]. 

It should be emphasized that the problem, which we address here, is somewhat different from that usually discussed in the context of protein physics [5-9]. We are not aiming at the search for a unique three-dimensional (native) conformation with a fast folding rate. On the contrary, we are interested in a state with a large entropy. In general, our aim is to learn whether it is possible to make with synthetic copolymers a step along the same line as molecular evolution. 

Bastioli et al.172 claimed expanded articles from extruded compositions of starch, mixtures of EAA and EVOH copolymers, and an inorganic carbonate. Typically, the synthetic copolymers comprised 20-40% of the composition. Preferred extrusion temperatures were in the range 180°C to 210°C. Extrusion of a typical blend in a single-screw extruder at a temperature of 180°C produced a closed cell foam with a density of approximately 1.2 lb/ft3 (19kg/m3). 

A synthetic copolymer provides additional degrees of freedom in the arrangement of the repeating units. For example, the spectrum of a copolymer of vinylidine chloride and isobutylene, shown in Fig. 13.5, indicates that various tetrad sequences (sequences of four monomer units) display significantly different spectra. Copolymers composed of more than two monomer types, including biopolymers, have much more complex spectra, as we discuss later. 

Nitrile (synthetic copolymer) has poor flexibility, but is strong and highly chemical resistant. 

The synthetic copolymers described in the previous section are particularly simple molecules compared to the macromolecules that occur in living systems. Virtually all bio-polymers exhibit some amphiphilic character, due to the presence of polar and lipophilic patches in the single molecule. 

The complex molecular architecture of proteins and enzymes leads to more subtle aggregation properties than those of synthetic copolymers. In particular, the chirality of these biological molecules offers an extra degree of freedom to the self-assembly process. This is discussed in more detail in the next section for now we neglect the effect of chirality. 

Synthetic copolymers have both molecular-weight and chemical composition distributions and copolymer molecules of the same molecular size, which are eluted at the same retention volume in SEC, may have different molecular weights in addition to different compositions. This is because separation in SEC is achieved according to the sizes of molecules in solution, not according to their molecular weights or chemical compositions. 

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