Basics Glossary Carbon
Basics Glossary Carbon neutral In bioplastics MAGAZINE again and again the same expressions appear that some of our readers might (not yet) be familiar with. This glossary shall help with these Amylopectin terms and shall help avoid repeated explanations such as ‘PLA (Polylactide)‘ in various articles. Readers who know better explanations or who would like to suggest other explanations to be added to the list, please contact the editor. [*: bM ... refers to more comprehensive article previously published in bioplastics MAGAZINE) Polymeric branched starch molecule with very high molecular weight (biopolymer, monomer is à Glucose). Amyloseacetat Linear polymeric glucose-chains are called à amylose. If this compound is treated with ethan acid one product is amylacetat. The hydroxyl group is connected with the organic acid fragment. Amylose Polymeric non-branched starch molecule with high molecular weight (biopolymer, monomer is à Glucose). Biodegradable Plastics Biodegradable Plastics are plastics that are completely assimilated by the à microorganisms present a defined environment as food for their energy. The carbon of the plastic must completely be converted into CO 2 .during the microbial process. For an official definition, please refer to the standards e.g. ISO or in Europe: EN 14995 Plastics- Evaluation of compostability - Test scheme and specifications. [bM 02/2006 p. 34f, bM 01/2007 p38]. Blend Glossary Mixture of plastics, polymer alloy of at least two microscopically dispersed and molecularly distributed base polymers. Carbon neutral describes a process that has a negligible impact on total atmospheric CO 2 levels. For example, carbon neutrality means that any CO 2 released when a plant decomposes or is burnt is offset by an equal amount of CO 2 absorbed by the plant through photosynthesis when it is growing. Cellophane Clear film on the basis of à cellulose. Cellulose Polymeric molecule with very high molecular weight (biopolymer, monomer is à Glucose), industrial production from wood or cotton, to manufacture paper, plastics and fibres. Compost A soil conditioning material of decomposing organic matter which provides nutrients and enhances soil structure. Compostable Plastics Plastics that are biodegradable under ‘composting’ conditions: specified humidity, temperature, à microorganisms and timefame. Several national and international standards exist for clearer definitions, for example EN 14995 Plastics - Evaluation of compostability - Test scheme and specifications [bM 02/2006 p. 34f, bM 01/2007 p38]. Composting A solid waste management technique that uses natural process to convert organic materials to CO 2 , water and humus through the action of à microorganisms [bM 03/2007]. Copolymer Plastic composed of different monomers. Fermentation Biochemical reactions controlled by à microorganisms or enyzmes (e.g. the transformation of sugar into lactic acid). Gelatine Translucent brittle solid substance, colorless or slightly yellow, nearly tasteless and odorless, extracted from the collagen inside animals‘ connective tissue. Glucose Monosaccharide (or simple sugar). G. is the most important carbohydrate (sugar) in biology. G. is formed by photosynthesis or hydrolyse of many carbohydrates e. g. starch. 34 bioplastics MAGAZINE [04/08] Vol. 3
Humus In agriculture, ‘humus’ is often used simply to mean mature à compost, or natural compost extracted from a forest or other spontaneous source for use to amend soil. Hydrophilic Property: ‘water-friendly’, soluble in water or other polar solvents (e.g. used in conjunction with a plastic which is not waterresistant and weatherproof or that absorbs water such as Polyamide (PA). Hydrophobic Property: ‘water-resistant’, not soluble in water (e.g. a plastic which is waterresistant and weatherproof, or that does not absorb any water such as Polethylene (PE) or Polypropylene (PP). Microorganism Living organisms of microscopic size, such as bacteria, funghi or yeast. PCL Polycaprolactone, a synthetic (fossil based), biodegradable bioplastic, e.g. used as a blend component. PHA Polyhydroxyalkanoates are linear polyesters produced in nature by bacterial fermentation of sugar or lipids. The most common type of PHA is à PHB. PHB Polyhydroxyl buteric acid (better poly-3-hydroxybutyrate), is a polyhydroxyalkanoate (PHA), a polymer belonging to the polyesters class. PHB is produced by micro-organisms apparently in response to conditions of physiological stress. The polymer is primarily a product of carbon assimilation (from glucose or starch) and is employed by micro-organisms as a form of energy storage molecule to be metabolized when other common energy sources are not available. PHB has properties similar to those of PP, however it is stiffer and more brittle. PLA Polylactide, a bioplastic made of polymerised lactic acid. Saccharins or carbohydrates Saccharins or carbohydrates are name for the sugar-family. Saccharins are monomer or polymer sugar units. For example, there are known mono-, di- and polysaccharose. à glucose is a monosaccarin. They are important for the diet and produced biology in plants. Sorbitol Basics Glossary Sugar alcohol, obtained by reduction of glucose changing the aldehyde group to an additional hydroxyl group. S. is used as a plasticiser for bioplastics based on starch . Starch Natural polymer (carbohydrate) consisting of à amylose and à amylopectin, gained from maize, potatoes, wheat, tapioca etc. When glucose is connected to polymer-chains in definite way the result (product) is called starch. Each molecule is based on 300 -12000-glucose units. Depending on the connection, there are two types à amylose and à amylopectin known. Starch (-derivate) Starch (-derivates) are based on the chemical structure of à starch. The chemical structure can be changed by introducing new functional groups without changing the à starch polymer. The product has different chemical qualities. Mostly the hydrophilic character is not the same. Starch-ester One characteristic of every starch-chain is a free hydroxyl group. When every hydroxyl group is connect with ethan acid one product is starch-ester with different chemical properties. Starch propionate and starch butyrate Starch propionate and starch butyrate can be synthesised by treating the à starch with propane or butanic acid. The product structure is still based on à starch. Every based à glucose fragment is connected with a propionate or butyrate ester group. The product is more hydrophobic than à starch. Sustainable An attempt to provide the best outcomes for the human and natural environments both now and into the indefinite future. One of the most often cited definitions of sustainability is the one created by the Brundtland Commission, led by the former Norwegian Prime Minister Gro Harlem Brundtland. The Brundtland Commission defined sustainable development as development that ‘meets the needs of the present without compromising the ability of future generations to meet their own needs.’ Sustainability relates to the continuity of economic, social, institutional and environmental aspects of human society, as well as the non-human environment). Thermoplastics Plastics which soften or melt when heated and solidify when cooled (solid at room temperature). Yard Waste Grass clippings, leaves, trimmings, garden residue. bioplastics MAGAZINE [04/08] Vol. 3 35
