Polymeric organic carbon

Making monomeric and polymeric organic carbonates by using CO as one of the raw materials is important for two reasons. Aromatic polycarbonates are well established as engineering plastics with an annual worldwide production of about 2 million tons. Aliphatic polycarbonates are under vigorous developmental efforts as they may have similar potential applications. 

Additionally, if a selected polymeric DCA is properly matched to a particular boiler operating temperature and pressure, there should be no increase in the total organic carbon (TOC) level of the steam. 

Finally, synthetic metals made of polymeric organic molecules may also show the property of ferromagnetism. Organic materials of this kind were first demonstrated in 1987 by Ovchinnikov and his co-workers at the Institute of Chemical Physics in Moscow. The polymer they used was based on a polydiacetylene backbone, which contains alternating double-single and triple-single bonds between the carbon atoms of the molecule (10.2). 

The blending of polymeric organic carbonyl compounds, e.g., ethylene/carbon monoxide copolymer, with the parent polymer, e.g., polyethylene, gives a plastic film material that degrades within 3 months. 

The Fischer-Tropsch synthesis, which may be broadly defined as the reductive polymerization of carbon monoxide, can be schematically represented as shown in Eq. (1). The CHO products in Eq. (1) are any organic molecules containing carbon, hydrogen, and oxygen which are stable under the reaction conditions employed in the synthesis. With most heterogeneous catalysts the primary products of the reaction are straight-chain alkanes, while the secondary products include branched-chain hydrocarbons, alkenes, alcohols, aldehydes, and carboxylic acids. The distribution of the various products depends on both the type of catalyst and the reaction conditions employed (4). 

Abstract The past two decades have profoundly changed the view that we have of elemental carbon. The discovery of the fullerenes, spherically-shaped carbon molecules, has permanently altered the dogma that carbon can only exist in its two stable natural allotropes, graphite and diamond. The preparation of molecular and polymeric acetylenic carbon allotropes, as well as carbon-rich nanometer-sized structures, has opened up new avenues in fundamental and technological research at the interface of chemistry and the materials sciences. This article outlines some fascinating perspectives for the organic synthesis of carbon allotropes and their chemistry. Cyclo[n]carbons are the first rationally designed molecular carbon allotropes, and... 

Several major matrix types are found in marine particles and sediments. Marine organisms surround themselves with tough polymeric organic cell walls and/or with opal or calcium carbonate tests. These contrasting matrices respond differently to various analytical methods. In sediments, the remains of these organisms combine with clay minerals to form a heterogeneous mixture. In this section, the influence of these matrices on analyte quantification are discussed. 

In this chapter we (1) present a rationale for distinguishing between the metabolism of monomeric and polymeric DOM (2) review what is known about the sources, concentration, and composition of the monomeric organic carbon pool in aquatic environments (3) discuss factors that contribute to the biodegradability of DOM and (4) describe contrasting views of what DOM molecules support bacterial heterotrophy. 

Decomposition and polymerization Activated carbon at elevated temperatures may act as a catalyst for the polymerization and/or decomposition of some organic compounds. The products of these polymerizations and/or decomposition reactions could interfere with the adsorption of the desired gases and the regeneration of the adsorbent. 

In lakes, the pool of dissolved organic carbon (DOC) is dominated by dissolved humic substances (up to 80% of the DOC). Lake humic substances are similar to soil humic substances in that carboxyl, hydroxyl, phenol, and probably methoxyl groups are of major significance. Fluorescence spectra of DOC may be interpreted in terms of the different geochemical origins of DOC (e.g., allochthonous versus algal derived). One or more moieties of dissolved humic substances are produced autochthonously mechanisms may include polymerization of phenols (promoted by transition metals), Maillard condensations, or oxidation via phenolase systems. Aliphatic structural units in dissolved humic substances provide a flexible conformation to the humic substance molecule. ... 

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