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bioplasticsMAGAZINE_1402

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bioplasticsMAGAZINE_1402

People Basics Fig. 5:

People Basics Fig. 5: Photo 3 growth media for hydroponics Fig. 6: acoustic insulator( Courtesy Recticel) Fig. 7: Viscoelastic flexible PU foam ( Courtesy BayerMaterial Science) resistance and durability. PU coatings include a variety of types, ranging from traditional pure polyurethane coatings to those in which isocyanates are used to modify resin systems through to polyurea formulations. Traditionally used primarily as liquid topcoats over epoxies and other primers/basecoats, polyurethane is found in coatings for use in metal electrodeposition primers, primer coats, base coats, and topcoats used for automotive, engineering equipment and appliances. PU wood coatings are mainly used for furniture and outdoor decking. High performance PU coatings are also used to protect exterior concrete flooring and metal components. Textile and fibre used in high performance sports and military clothing are also treated with PU coatings. PU Adhesives, Binders & Sealants PU adhesives are used in many market segments and a multitude of applications. Polyurethanes compete with other medium to high performance adhesives such as SBR, polyamides, polyesters, epoxies, cyanoacrylates, PVA, acrylics, PVDC and others. Construction, transportation and flexible packaging represent the leading applications for PU adhesives. PU Elastomers (cast, microcellular) Elastomers are characterized by their ability to recover from deformation so that after the material has been stressed it generally returns to its original shape and form. PU elastomers can be made to exhibit a wide range of hardness, abrasion resistance, elongation and impact resistance. Cast elastomers are processed by pouring material into a mould. The finished article is cured at either ambient or elevated temperatures of 50-130ºC to produce a hard, solid elastomer that is highly durable, abrasion resistant, solvent resistant and flexible. This type of elastomer can be used in hundreds of different applications but typical uses include wheels, rollers, belting, seals, industrial components and mining screens. Microcellular elastomers are lightweight materials that are moulded into a foamed article for use in shoe soles (Fig. 8) and shock absorbers in vehicles. Spray elastomers- are applied using high pressure equipment to produce a protective coating on a variety of substrates. A prominent area of development is that of spray polyurea elastomers; these products have a wide range of applications including flooring, roofing, pipelines, tanks and car park decking. Growing role of bio based materials Opportunities for biobased PU continues to grow, in flexible block foam, moulded foams for automotive seats, as well as for coatings, adhesives, and elastomers where the biobased chemicals : offer equivalent or better performance than those derived from crude oil are available on a reliable basis at an equivalent purity do not increase production costs do reduce reliance upon crude oil do reduce price volatility of raw materials do improve the carbon footprint of a production process, product and consumer product as well as reducing pollution and GHG emissions 52 bioplastics MAGAZINE [02/14] Vol. 9

Fig. 8: Coloured PU elastomer shoe soles ( Courtesy ISL Chemie) Fig. 9: Palm oil, cashew nut and castor oil plants ( courtesy Polygreen, CIMC Italia, BASF ) Currently the bio-PU market is at a tipping point due to the increasing volume and range of biobased products entering the market. For decades products such as sorbitol polyols and castor oil have been used by PU manufacturers. More recently natural oil polyols derived from soybean oil, cashew nut shell oil, fish oil, palm oil, rapeseed oil and sunflower oil have entered the raw material mix (Fig. 9). Some of these products are starting to be used in mainstream polyurethane products such as car seats, mattresses, elastomers and coatings. In addition to the use of natural oils, a new breed of chemicals is being produced through the use of renewable resources such as sugar, corn, glycerine, wood pulp and waste paper with fermentation and biotechnology. During 2012, an innovative group of small companies have made the leap into biobased chemical production creating evidence that a new industry using sugar rather than petroleum has started to grow. This group includes BioAmber, BASF, CSM, Gevo, LS9, Lanxess, Myriant Technologies, Reverdia, Rivertop Renewables, Solazyme and ZeaChem. The output from the facilities, mostly chemical intermediates, will be sold to chemical and other companies to make products such as polyols, solvents, detergents, coatings, and polymers. The intermediates include isobutyl alcohol, glucaric acid, succinic acid, acetic acid, and farnesene. By 2015, new biosuccinic acid plants expected to come on stream will have capacity of nearly 200,000 tonnes per annum. Bio succinic acid can be used to produce polyester polyols which are predominantly used in PU elastomers, TPUs, coatings and adhesives. Commercially available quantities of biobased chemicals that are identical to petrochemical based products have captured the interest of the industry, most notably in high performance products such as coatings, elastomers and adhesives. Growth rates for biobased chemicals such as polyester polyols will depend upon the success of each manufacturer to substitute conventional material. This would seem more straightforward than in the case of switching polyether polyols for natural oil polyols – materials that have different chemical structures, colour, odour and reactivity. The level of investment in bio –based chemicals has increased rapidly, although much has been paid for by NGO and government grants, this would suggest that manufacturers see excellent growth prospects. BASF suggests that the global growth in the use of renewable chemicals will increase by 4-6 % per year depending upon the end-use application. Bayer Material Science suggest that the benefits of products such as bio-succinic acid and bio-BDO are greater than for NOPs because the processes are more efficient, save money and are more competitive than for conventional products (Fig. 10). In addition, chemists have found catalysts that can capture carbon dioxide for use as a raw material. The potential demand for these products to replace conventional petrochemical ones as well as create new products is huge. BayerMaterialScience, Novomer and several other polyol manufacturers have made trial volumes of CO 2 based polyols and used them to produce PU products such as TPUs, shoe sole elastomers, flexible foams and adhesives. bioplastics MAGAZINE [02/14] Vol. 9 53

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