Starch, renewable material

The fermentation industry is based almost exclusively on renewable materials in the form of molasses, starch, etc. Most products are of very high value and relatively low volume such as antibiotics (qv) (23). 

Starch and cellulose are potentially important renewable resources for chemical production. Glucose (a component of starch) is relatively easy to obtain from plant material and is used to synthesize existing chemicals. While this is so, the production of such renewable materials, a full fife-cycle assessment of the requirements for their production suggest that much fossil-soiuced energy and material would stiU be employed in the growing, harvesting and processing of biomass. 

Vigneshwaran et al. (2006) s mthesized stable silver nanoparticles by using soluble starch as both the reducing and stabilizing agents. The use of environmentally benign and renewable materials like soluble starch offers numerous benefits of eco-friendliness and compatibility for pharmaceutical and biomedical applications. 

Biobased polymers from renewable materials have received increased attention recently. Lactate is a building block for bio-based polymers. In the United States, production of lactic acid is greater than 50,000 metric tons/yr and projected to increase exponentially to replace petroleum-based polymers. Domestic lactate is currently manufactured from corn starch using the filamentous fungus Rhizopus oryzae and selected species of lactic acid bacteria. The produced lactic acid can then be polymerized into polylactic acid (PLA) which has many applications (Hatti-Kaul et al., 2007). However, so far, no facility is built to use biomass derived sugars for lactic acid production. More research needs to be done to develop microbes using biomass derived sugars for lactate production. 

Starch is still quite widely used as an adhesive in our modern, high tech world. Its adhesive properties are developed differently for different products, and starch-based adhesive is used in a large variety of applications. From the standpoint of its being a renewable resource, a reliable performer, and a low-cost raw material, starch would seem to be an adhesive ingredient on the market for a long time into the future. 

Coco-Based Surfactants. The most important coconut oil-based surfactants are fatty alcohol sulfate, fatty alcohol ether sulfate, and fatty alcohol polyglycol ether. Two relatively new coco-based surfactants are fatty acid methyl ester sulfonate and alkyl polyglycoside, which is produced from fatty alcohol and starch or sugar, both renewable materials. 

Bioethanol produced from biomass resources by fermentation is the most promising biofuel and the starting material of various chemicals. Starch is a cheap, clean, nontoxic, renewable Ccirbon source for bioethanol production [1]. In the process currently employed for industrial-scale ethanol production from starchy materials, starch is first hydrolyzed by adding a liquefying enzyme, a-amylase (EC 3.2.1.1), to avoid gelatinization and then... 

They are seminatural produets, produeed from a renewable natural material (starch) by employing a relatively simple enzymic conversion. 

Blending and compositing have been successfully used in starch-based materials. Starch was initially used a fillers blended with various polymers, especially with polyolefin. Blending starch with biodegradable polymers has attracted more and more attention. The interest in new nanoscale fillers has rapidly grown since it was discovered that a nanostructure could be built from a polymer and a layered nanoclay. These new nanocomposites show dramatic improvement in mechanical properties with low filler content. Cellulose is the major substance obtained from vegetable fibers, and applications for cellulose fiber-reinforced polymers have again come to the forefront with the focus on renewable feedstocks. Hydrophilic cellulose fibers are very compatible with most natural polymers. 

Starch is one of these renewable resources. Starch is widely available and is especially suited for the production of foamed thermoplastic materials due to the intrinsic presence of a blowing agent. Destructurization of starch by means of extrusion compounding will facilitate the formation of expandable beads or foams of thermoplastic starch. 

The development and use of materials from renewable sources is not a new concept. Besides providing food, feed, clothes, shelter, and energy, biomass has been employed since ancient times to extract valuable products such as medicinal drugs, flavors, and fragrances. With the development of civilization of human society, in the nineteenth century various biomass resources were employed for the large-scale industrial production of chemicals and durable materials, such as cellulose esters (nitrate and acetate), oxidized linseed oil (linoleum), vulcanized rubber, adhesives from starches, and so on. However, the widespread use of such renewable materials diminished in the twentieth century since the development of fossil fuel derivatives, leading to the polymer renaissance. Today commodity polymers such as polyolefins are ubiquitous in our societies because they represent the optimal choice based on several factors, including monomer cost and... 

Cyclodextrins (CDs) have never ceased to fascinate scientists around the world due to their structures and properties [1], These inexpensive natural cyclic oligosaccharides could be obtained from the enzymatic degradation of a renewable material, namely starch. This family of water-soluble macrocycles are built up from D-(+)-glucopyranosyl units linked by a-l,4-glycosidicbonds (Fig. 2.1). In the enzymatically produced CD family, three derivatives are mainly known a-, (3-, and y-CD, constituted of six, seven, and eight glucose units, respectively (Fig. 2.1). 

Starch is a fully biodegradable natural polymer, which has a wide variety and a wide range of resources, so it is an ideal natural renewable materials. Depending on the plant, starch generally contains 20% to 25% amylose and 75% to 80% amylopectin. [94]... 

The top left quarter of Figure 10.4 comprises thermosetting bio-derived resins that typically do not feature in packaging applications and so will not be discussed further. Most interestingly, in the context of biodegradable, renewable materials is the top right quarter that comprises polylactic acid (PLA), starch, polyhydroxy butyrate, whey protein, and so on. Each of the petrochemical and non-petrochemical derived IWSPs are discussed in turn below. 

A range of different technologies can be used to industrially convert the available biomass into renewable materials or energy carriers. Industrial activities using renewable materials are very often linked to the food sector. Many of the renewable raw materials that can be considered for technical industrial applications can be made in food processing plants. For example, sucrose or starch, or natural oils for human food use are also important raw materials for industrial processes. The following industrial sectors supply the most important renewable raw materials ... 

Several and various products are proposed for the market and are diflSeult to quantify. For example, we find materials made of renewable resources (starch and mixtures of starch with polylactic acid, polyhydroxyalcanoates, etc.), of fossil resources (polyesters, etc.) and of a mixture of both materials (composites). However, for environmental reasons and to promote sustainable development, the trend is to use renewable resources rather than fossil resources to make these materials. Table 19.6 shows examples of materials and producers. 

Being both renewable and relatively inexpensive, starch is a popular biopolymer for replacing petroleum based materials. Starch based bioplastics, for instance, have received much attention, and there is much room to improve the properties and enlarge the uses of starch fibers. 

A rather impressive Hst of materials and products are made from renewable resources. For example, per capita consumption of wood is twice that of all metals combined. The ceUulosic fibers, rayon and cellulose acetate, are among the oldest and stiU relatively popular textile fibers and plastics. Soy and other oilseeds, including the cereals, are refined into important commodities such as starch, protein, oil, and their derivatives. The naval stores, turpentine, pine oil, and resin, are stiU important although their sources are changing from the traditional gum and pine stumps to tall oil recovered from pulping. 

Recently, however, we have embarked on a programme aimed at developing biodegradable and renewable support materials based on the very abundant sources of biomass such as starch, chitosan and cellulose, in addition to the inorganic materials mentioned above. 

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