Raw materials for polymers

Starch has been considered an attractive raw material for polymer applications for almost 200 years. Kirchoff s discovery in 1811 that treatment of starch with an acid yields a sweet substance was an unexpected result of the search for a low-cost substitute for natural rubber.1 Considerable research in the development of starch-based polymer materials has been stimulated by the facts that starch is produced from wide variety of sources, is an annually renewable resource and is inherently biodegradable. 

Classification by End Use Chemical reactors are typically used for the synthesis of chemical intermediates for a variety of specialty (e.g., agricultural, pharmaceutical) or commodity (e.g., raw materials for polymers) applications. Polymerization reactors convert raw materials to polymers having a specific molecular weight and functionality. The difference between polymerization and chemical reactors is artificially based on the size of the molecule produced. Bioreactors utilize (often genetically manipulated) organisms to catalyze biotransformations either aerobically (in the presence of air) or anaerobically (without air present). Electrochemical reactors use electricity to drive desired reactions. Examples include synthesis of Na metal from NaCl and Al from bauxite ore. A variety of reactor types are employed for specialty materials synthesis applications (e.g., electronic, defense, and other). 

Succinic acid is currently manufactured by the hydrogenation of maleic anhydride to succinic anhydride, followed by hydration to succinic acid. A fermentation process for succinic acid production is desirable because in such processes, renewable resources such as starchy crops and other agricultural products can be used as feedstock for the biological production of succinic acid. It addition, a high purity product, which is required as raw material for polymer manufacture, can be obtained. 

L-Aspartate is used in parenteral nutrition and food additives, and as a starting material for the low-calorie sweetener aspartame, aspartyl-phenylalanine methyl ester. Recently, the possibility of using L-aspartate as a raw material for polymer production was studied very hard since it has three reactive residues in the molecule and the resulted polymers could be biodegradative. It is used as a detergent and chelating or water treating agent. 

Z oldine . [Angus] Oxazolidines cross-linking agent, analyst, resin reactant, formaldehyde substitute, corrosion inhibitor, tanning agent, raw material for polymer synthesis. 

Linear aliphatic chols are widely used as raw materials for polymers. Polymers synthesized from even-carbon diols tend to show excellent polymer properties. 1,4-Butanediol is very important as raw material for various polymers such as urethanes and polybutylene terephthalate (PBT), which is an engineering plastic. Since Celanese Corporation described a PBT resin in 1970, the demand for PBT resin, which is mainly used for automotive, electrical, and electronic equipment parts, has been expanding rapidly [1]. THF is also a major 1,4-butanediol derivative as a raw material for poly(tetramethylene ether) glycol used for artificial leather and elastic fibers in addition to being a high-performance solvent. Significant growth in demand for these 1,4-butanediol derivatives is expected in Asia, primarily in China. 

Coal can liberate the U. S. from the plastics shortage as well as the energy crisis. It is abundant, and we have the technology to convert it to precursors for plastics at costs that are suddenly cheap compared to the price tags on chemicals from Imported petroleum. Ethylene, propylene, benzene, toluene, xylene, phenol and other raw materials for polymers and plastics can become plentiful again but we must speed up R D as well as plant construction. 

There are various ways of proceeding from raw materials for polymers, that is, from monomers or prepolymers, to shaped plastics A, direct polymerization with simultaneous shape forming B, polymerization to... 

Although the composition of the aliphatic suherin has been thoroughly studied for many plant species [14], the physical properties of the ensuing mixtures of monomeric components, as well as their use as raw materials for polymer synthesis, are still poorly studied topics. The following sections provide a general overview of the published data on the physical properties of depol5mierized suberin mixtures and on their applications in the synthesis of pol3meric materials. 

As mentioned before, there are a few biodegradable polyesters which were historically obtained from renewable sources as their production concerns fermentation or microbial processes from vegetable raw material (i.e., PLA, PHA and more recently polyhydroxyfattyacid). Moreover, in the last 5 years an increasing interest in renewable raw material for polymer synthesis has been developed, not only for biodegradable polyester production but also for nonbiodegradable polymers such as polyethylene or PET. 

This has prompted research activities all over the world to find alternative feedstocks for polymers. Agricultural by-products and forest products have become more attractive these days as renewable resources for polymers and plastics additives. Plant exudates such as gum arable, gum ghatti, gum karaya, gum tragacanth etc. have been used in textiles, cosmetics and pharmaceuticals mainly as emulsifiers and thicknersl. Other types of gums from seed such as guar gum have similarly been used. But these have not been utilized as the raw material for polymer manufacture. 

Since TMA is a petroleum based chemical, its price and supply are likely to be affected adversely in the future. In an attempt to find a suitable substitute for TMA, we have developed gum rosin, the exudate of conifer trees such as pine, as a source of raw materials for polyesterimide "" and polyamideimide resins. Our present program aims at the development of gum rosin as cheap, dependable and renewable source of raw material for polymers that are expected to be a substitute for TMA-based polymers and other thermostable polymers. 

We have found that RMA appears to be a suitable substitute for TMA as a raw material for polymers. Rosin polymers such as polyeste-rimides via RMA or RMID or its derivative possess similar solubility and other characteristics to those synthesized from TMA. The thermal behavior of a polyesterimide (PEI-2) from rosin has been compared with that of TMA-based polyesterimides (Table 4). It is found from Table 4 that the thermal stability of the polyesterimide from RMA is similar to that of TMA. The glass transition temperature,... 

Liquefied wood is also an interesting raw material for polymer preparation. Wood flour contains lignin, cellulose, and hemicellulose, and can be liquefied with phenol or glycol in the presence of an acid or base catalyst, or at high temperature (>250 °C) or in sub-/super-critical fluid e.g. water, alcohols, and... 

Unfortunately, the LCPs are often too expensive for general engineering applications. On the other hand, there are considerable supplies of engeneering plastics in the form of post-consumer scraps, which are a low cost source of raw materials for polymer blends. However, unlike LCPs, the molecules of common thermoplastics relax during melt processing therefore a good molecular orientation is almost impossible. 

Since nearly all modem polymers have their origins in petroleum, it has been argued that this increased reliance on polymers constitutes an unnecessary drain on energy resources. However, the raw materials for polymers account for less than two percent of total petroleum and natural gas consumption, so even the total elimination of synthetic polymers would not contribute significantly to the conservation of hydrocarbon resources. Furthermore, when total energy costs... 

The third reason. Stating that oligomer is a condensed state of matter and it has specific properties we renounce the traditional attitude to oligomers as only raw materials for polymer industry and want to attract more fundamental attention to oligomeric systems not limited by material science only (you can see more details throughout this book). 

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