Other Renewable Materials

The myrcene-based polyols are obtained by classic reactions of double bonds. 

Based on data from the literature, some important renewable resources used for polyols for polyurethane fabrication, without any attempt at an exhaustive presentation are presented. There are many ways of transforming natural renewable raw materials into polyols, as a consequence of the creativity and ingenuity of chemists. There are many possibilities for valorification of natural renewable materials in the area of polyols for PU. 

Many important developments are very confidential and in the literature there is not much available, very concrete information about many new processes for the transformation of natural 

A lot of research and development in this area was made in Malaysia and in Latin America (Peru, Venezuela, Brazil, Mexico), both big producers of vegetable oils and natural products [75]. 

Soy Oil Systems successfully developed new polyols based on soybean oil oxidation (oxygen blown oils). Many other companies and research centres are involved in serious research on the valorification of natural renewable resources by transforming them into polyols and into PU. Very important research on unsaturated vegetable oil, chemical transformation into polyols for PU were developed in Pittsburg State University, Kansas (under Professor Zoran Petrovic), Henkel and Cognis (Sovermol polyols), Unichema (dimer acids and dimer diols etc.), Bayer, Cargill and other companies. 

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The replacement of timber products by nonrenewable materials is an unfortunate development, since it has been repeatedly shown that the use of timber does have associated environmental benefits compared with the use of nonrenewables (e.g. Marcea and Lau, 1992 Hillier and Murphy, 2000 Bowyer etal., 2003 Lippke etal., 2004). Timber has a lower embodied energy content (and hence a more favourable carbon emission profile) compared to most other building materials and can provide other benefits, such as improved thermal properties. It and the products made from it (in common with other renewable materials) can be used as a repository for atmospheric carbon dioxide. Wood is derived from a renewable resource, albeit potentially an exhaustible one unless it is managed correctly. Disposal of wood can be readily achieved with little environmental impact (subject to how the wood has been treated prior to disposal). 

Bioplastics today can be made from corn, soy, sugarcane, potato, or other renewable material source. Petroleum plastics can also be sustainable if they are made from renewable or recycled material sources. The manufacturing process also can also be sustainable. Plastics have the opportunity to define sustainable materials that are made from renewable or recycled materials sources, made with lower energy, produce less pollution, and have a low carbon footprint. Sustainable plastic materials also are recycled or composted at the end of the product service life. 

Biodiesel is diesel fuel produced from vegetable oils and other renewable resources. Many different types of oils can he used, including animal fats, used cooking oils, and soybean oil. Biodiesel is miscible with petroleum diesels and can he used in biodiesel-diesel blends. Most often blends are 20 percent biodiesel and 80 percent traditional diesel. Soy diesel can be used neat (100%), hut many other types of biodiesel are too viscous, especially in winter, and must be used in blends to remain fluid. The properties of the fuel will vaiy depending on the raw material used. Typical values for biodiesel are shown in Table 1. 

Nuclear fission power plants were at one time thought to be the answer to diminishing fossil fuels. Although the enriched uranium fuel was also limited, an advanced nuclear reactor called breeders would be able to produce more radioactive fuel, in the form of plutonium, than consumed. This would make plutonium fuel renewable. Although plutonium has been called one of the most toxic elements known, it is similar to other radioactive materials and requires careful handling since it can remain radioactive for thousands of years. 

Renewable raw materials are made or derived from short-term renewable sources (one to a few years or a few tens of years) such as plants, trees, wood wastes and other agricultural products. Not all these materials are necessarily biodegradable. Natural rubber, for example, comes from the latex of a tree (Hevea brasiliensis) and is not biodegradable. Renewable materials are often considered as opposites to fossil sources such as petroleum that are not renewable on a human timescale. On the other hand, some synthesized plastics such as certain polyesters are biodegradable. 

Other renewable resources sorbitol (I), cellobiose (XXV), etc. can be used in similar ways as starting materials in the preparation of epoxy resins. We are now working on a direct two-step preparation of diepoxy sorbitol derivatives by direct halogenation of the two primary hydroxyl groups with the formation of 1,6-dichloro-1,6-dideoxy-sorbitol, (XXIII), followed by epoxy ring formation (1,2 5,6-dianhydrosorbitol (XXIV) ... 

While this reaction is substantially exothermic (6), it provides an intriguing approach to the production of fuels from renewable resources, as the required acids (including acetic acid, butyric acid, and a variety of other simple aliphatic carboxylic acids) can be produced in abundant yields by the enzymatic fermentation of simple sugars which are, in turn, available from the microbiological hydrolysis of cellulosic biomass materials ( ] ) These considerations have led us to suggest the concept of a "tandem" photoelectrolysis system, in which a solar photoelectrolysis device for the production of fuels via the photo-Kolbe reaction might derive its acid-rich aqueous feedstock from a biomass conversion plant for the hydrolysis and fermentation of crop wastes or other cellulosic materials (4). 

V/hen the Toro is left for a long time, it generally loses its viscosity due to the degeneration of the glutinous rice starch and by the action of the other component materials(Table 15) It must be renewed as far as possible. 

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