MACROMOLECULAR PROPERTIES

The final goal of all attempts is a description, and hopefully also a reliable prediction, of the macromolecular properties in bulk and in moderately concentrated solutions. It may be useful to recall that even the polymerization processes are conducted either in the melt or in fairly concentrated solutions. Under such conditions a complex interplay between the structures of the individual macro-molecules with strong mutual interactions takes place. In order to disentangle the complexity it will be helpful to derive at first a precise picture of the structure of individual macromolecules. Their properties can most adequately be studied... 

Traditionally, soluble polymers have received less attention as polymeric supports than their insoluble counterparts. A perceived problem with the use of soluble polymers rested in the ability to isolate the polymer from all other reaction components. Yet, in practice this separation is not difficult and several methods have capitalized on the macromolecular properties of the soluble support to achieve product separation in liquid-phase synthesis. Most frequently the homogeneous... 

The understanding of the macromolecular properties of lignins requires information on number- and weight-average molecular weights (Mn, Mw) and their distributions (MWD). These physico-chemical parameters are very useful in the study of the hydrodynamic behavior of macromolecules in solution, as well as of their conformation and size (1). They also help in the determination of some important structural properties such as functionality, average number of multifunctional monomer units per molecule (2, 3), branching coefficients and crosslink density (4,5). 

As can be expected, the initial degradation of DNA by acid DNase not only causes a drastic change in the macromolecular properties of the substrate, but also strongly affects its biological activity. Young and Sinsheimer 26) have been able to show that close to one diplotomic... 

Polymer identification starts with a series of preliminary tests. In contrast to low molecular weight organic compounds, which are frequently satisfactorily identified simply by their melting or boiling point, molecular weight and elementary composition, precise identification of polymers is difficult by the presence of copolymers, the statistical character of the composition, macromolecular properties and, by potential polymeric-analogous reactions. Exact classification of polymers is not usually possible from a few preliminary tests. Further physical data must be measured and specific reactions must be carried out in order to make a reliable classification. The efficiency of physical methods such as IR spectroscopy and NMR spectroscopy as well as pyrolysis gas chromatography makes them particularly important. 

On the basis of data from DOSY and diffusion editing, we now know that the components soluble in aqueous base tend not to be macromolecular (Simpson et al., 2002), at least not to the extents considered previously. More detail needs to be known about the nature of the associations that give pseudo-macromolecular properties. 

Swift, R. S., (1999). Macromolecular properties of humic substances Fact, fiction, and opinion. Soil Sci. 164,790-802. 

Macromolecular properties of grafted cellulosic fibers usually measured are differential solubility in either polymeric or cellulosic solvents, mechanical or physical properties, and abrasion resistances. The molecular weights of the grafted or block polymers and of cellulose, both before and after formation of macrocellulosic radicals, have been determined. The number of grafted or block polymer molecules per cellulose molecule calculated has usually been much less than one. Grafted cellulosic fibers exhibit second order transition temperatures, dependent on the composition of the grafted polymer (3, 4). 

Carlstedt, I. Sheehan, J. K. (1984). Macromolecular properties and polymeric structure of mucus glycoproteins. In Mucus and mucosa, ed. J. C. Nugent M. O Connor, pp. 157-72. Ciba Foundation Symposium, no. 109. Pitman Press London. 

McNaughton JG, Yean WO, Goring DAI (1967) Macromolecular properties of kraft lignins from spruce made soluble by a continuous flow process Tappi 50 548-553 Michell AJ, Watson AJ, Higgins HG (1965) An infrared spectroscopic study of deligmfication of Eucalyptus regnans Tappi 48 520-532... 

Stokke BT, Christensen BE, Smidsrdd O (2005) Macromolecular properties of xanthan. In Reference 3, p 433... 

One of the guiding principles underlying much of the physics in conventional polymers is that many macroscopic macromolecular properties, not least the structure formation, can be satisfactorily understood even when the details of single molecules are ignored [11]. As is discussed later in this review, this idea still remains relevant for the intermolecular self-organization of hairy-rod PFs and for their macroscopic alignment. However, much of the behavior seen in PFs (and virtually all other electronic polymers as well) is an excep-... 

Macromolecular properties of alginates are highly dependent on G/M ratio and sequential distribution of G and M residues within homopolymeric blocks. Poly-guluronate blocks are stiffer than polymannuronate and alternating blocks, which in turn are more soluble at low pH [6]. 

Giddings, J. C., Factors influencing accuracy of colloidal and macromolecular properties measured by FFF, Anal. Chem., 69, 552-557, 1997. 

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