Natural polymer defined

If you trace the word resin back far enough, you ll find that it was originally defined as a low molecular weight, natural polymer that is an exudate of (it exudes from) vegetable or non-vegetable matter. Examples are rosin (from pine trees), shellac (from insects), and both frankincense and myrrh (aromatic gums from an East African and an Asian species of tree). Resins like these do not flow if heat and pressure are applied, like plastics do. They decompose or melt. (This definition of resin is obsolete in commerce today.)... 

Comparable infrared (IR) spectra of complex organic solids such as coals (Fig. 7) 23), cherts, kerogens, humic substances and some natural polymers have been presented in various publications. They show a limited number of rather broad bands which are due to well defined chemical groups and can often be interpreted by comparison to less complicated spectra. The signals commonly observed in fossil organic matter are as follows (Robin et al., 1977 21), Tissot Welte, 1978 24), Rouxhet et al., 1980 22>, Friedel Carlson, 1972 25)) ... 

GPC is a form of size-exclusion chromatography (SEC) used by polymer chemists and plastics engineers for the characterization of synthetic or natural polymers. Separation is by effective molecular size or hydrodynamic volume using columns packed with materials of 5-10 pm particle size (e.g., cross-linked polystyrene gels) with well-defined pore distribution (see Table 7.8). 

The cell wall of Saccharomyces cerevisiae is made of mannoproteins bound to oligopolysaccharides which remain exposed on the outside of the cell. These mannoproteins are also bound to glucanos and chitin (Pretorius, 2000 Su z, 1997). The different polarities and the hydrophilic or hydrophobic nature of these wall polymers define the capacity of yeast to retain or adsorb different wine molecules such as volatile compounds, tty acids or pigments (Vasserot et al, 1997). 

Synthetic products have acquired a negative association due to synthetic food additives, but they show many valuable properties, especially in medical applications. Synthetic polymers are valuable for therapeutic use since they can be produced in a well-defined and controlled fashion, overcoming the greatest setback of natural polymers the batch-to-batch variation. Synthetic polymers often exhibit increased cytotoxicity due to the strong positive charge, but since they can be freely modified in order to introduce desired properties, their biocompatibility can be improved, for example by incorporation of biodegradable linkers and bioactive functionalities. ... 

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