Molecular weight organic compounds

Plastics are high-molecular-weight organic compounds of natural or mostly artificial origin. In fabrication, plastics are added with fillers, plasticizers, dyestuffs and other additives, wliich are necessary to lower the price of the material, and give it the desired properties of strength, elasticity, color, point of softening, thermal conductivity, etc. 

The term plastic comes from the Greek word to form. It identifies many different plastic materials. Polymers, the basic ingredients used in practically all plastics, can be defined as high molecular weight organic compounds, synthetic or natural substance... 

About half of the dissolved organic carbon may appear in humic or fulvic acids. These are high-molecular weight organic compounds of a composition which is somewhat uncertain. They contain aromatic hydroxyl and carboxyl groups which have the ability to bind to metal ions. Rivers and estuaries typically contain 10 mg/liter of acid with an exchange capacity of 5-10 mmol/g, mainly due to carboxylic... 

Any low-molecular-weight organic compounds are normally a gas at standard temperature and pressure (STP) may also be found in the soil solution. These compounds will be produced as a result of the decomposition of organic matter in soil. Many of these will be readily taken up and used by microorganisms and thus their life spans in the soil solution are short. 

The Chemical analysis of polymers is very similar to the Chemical analysis of low Molecular weight organic compounds, if we make suitable modification to ensure solubility or the availability of sites for reaction (e.g., insoluble specimens should be ground to expose a large surface area). The general methods used for functional group and elemental analysis are applicable. Chemical reactions of polymers also provide means of Chemical analysis, as also their reactions of degradation. 

Mycosporine-like Amino Acids (MAA) Small molecular weight organic compounds that absorb UV light and are thought to function as natural sunscreens. 

An allergen is a chemical or substance that results in an immimoglobulin E-mediated (antibody) allergic response. Allergens are usually high molecular weight organic compounds. The production of antibodies... 

Humic substances High-molecular-weight organic compounds that are variable in composiUon, have complex structures, and are relaUvely inert. They comprise a large fracUon of the DOM. Found in sods, sediment, fresh, and seawater. 

Table 2 Low-Molecular-Weight Organic Compounds Found in the Spent Liquors from Pulping and Bleaching Processes... 

Crosslinked polymers with functional groups have recently been used even more frequently as reagents for the synthesis of low-molecular-weight organic compounds since they are easily separated after conversion and sometimes can easily be regenerated. The immobilization of enzymes by attaching them to crosslinked polymers should also be mentioned. This technique has already found industrial applications. 

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