Liquid, definition macromolecular

This document provides definitions of the basic terms that are widely used in the field of liquid crystals and in polymer science (See references 1-39). It is the first publication of the Commission on Macromolecular Nomenclature dealing specifically with liquid crystals. 

As has been shown in an ever increasing number of practical systems, particularly polymers and biological macromolecular systems, solid state NMR/I is not only useful for real solids but also very important and perhaps indispensible for neither-solid-nor-liquid samples or both-solid-and-liquid samples, which are nowadays called soft materials . Hence, there is no definite boundary between solid state and liquid state NMR/I. 

In the course of this chapter three different liquid macromolecular colloid systems have been met with, which fulfil the definition of Sol in 1 b (p. 2) ... 

Aciemo D, Naddeo C (1994) Blends of PEEK and PET-PHB 60 a preliminary study on thermal and morphological aspects. Polymer 35(9) 1994-1996 Baron M, Stepto RFT (2002) Definitions of basic terms relating to polymer liquid crystals, lUPAC commission on macromolecular nomenclature. lUPAC recommendations. Pure Appl Chem 74 (3) 493-509... 

By definition, a solution contains more than one component. A solution can Ije gaseous, liquid, or solid. The term macromolecular (or polymer) solution will be used to indicate a mixture of a polymer with a small-molecule solvent and polymer blend when solvent and solute are both polymers. In this chapter the thermodynamics of polymer solutions and of solid polymer blends will thus be discussed separately. 

Thirdly, because of their large size macromolecules tend to present severe problems of solubility. Thus, even when they form solutions (or in some cases sols) they are thermodynamically unstable so that they readily precipitate out of the liquid phase if they are subjected to even small changes in say pH, temperature, ionic strength or solvent composition, for example addition of organic solvents. Clearly, since HPLC is by definition chromatography performed in the liquid phase, the macromolecular mixtures must be kept in this phase if the separation is to be successful, that is the analytes must not be allowed to precipitate out of solution either on the column or even off the column. 

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