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bioplasticsMAGAZINE_1404

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bioplasticsMAGAZINE_1404

Report Generation Zero

Report Generation Zero Bioplastics were the very beginning! Pic. 1: Bonboniere cover (Celluloid as eplacement for tortoiseshell) Pic. 2: Candle holder (casein as replacement for tortoiseshell) Due to the strong and growing use of plastics, some historians call the current time the plastics age. In 1983, with 125,000,000 m³ for the first time the global demand for plastics exceeded that of iron. But, the history of plastics is older than some historians and some people in the plastics business might expect: Modern man always looked for, and made use of, easily processable materials to ease daily life. In the history of plastics, according to Waentig, it can be distinguished between the following phases: • Origins (until1839), • era of imitating materials (1839 to 1914), • era of substitutes (from approx. 1914 to approx. 1950), • era of materials with novel properties (from approx. 1950). Some might have forgotten that the very first plastics were based on biopolymers. Already in the stone age, natural resins (biopolymers) were used as glue and in the middle ages manufactured products from the biopolymer milk protein (casein) were used for imitation of horn for inlays or little medallions. A recipe for making imitation horn is almost 500 years old, making it the oldest known text on creating a plastic. In around 1530 the Swiss merchant Bartholomaeus Schobinger met with the Bavarian Benedictine monk Wolfgang Seidel at the wealthy Fugger family´s residence. There, Seidel, a passionate collector and publisher of scientific texts, heard about an alchemist´s recipe that he later published in his writings under the title “The secret to creating a transparent material akin to beautiful horn” (see box next page). Social structures changed rapidly in the 18 th century. Urbanization took place, the bourgeoisie became wider and wealthier and required a higher level of scarce and expensive horn, nacre, tortoise shell and ivory for designed fashionable articles for daily use (see pictures). The demand for these natural materials – which, by the way, are all based on biopolymers – exceeded supply and opened the market for substitutes. Bois Durci, the hardened wood, was used mainly in France between 1855 and 1927 for the production of picture frames, write garnish, album covers, badges and other luxurious objects (picture 9). Bois Durci is a dark material, made from the biopolymer protein and many different filling materials. This moulding compound consisted of waste products: bovine blood from the many slaughterhouses around Paris, the megacity at that time, as well as sawdust from tropical wood from furniture production. At about the same time, at the end of the 19 th century, Milk Stone a resin based on casein was invented. Famous trademarks were Galalith and Erinoid (see box p. 38, top). It needed some effort to be produced and was more expensive than the later Celluloid, but it kept a certain market for a while because it was odorless and flammable. Pic. 3: Buttons (casein as replacement for nacre) 36 bioplastics MAGAZINE [04/14] Vol. 9

Report In the second half of the 19 th century the game of billiards became very popular in the USA and the demand for ivory for billiard balls threatened Ceylonese (today Sri Lanka) elephants with extinction. In 1869, thermoplastic celluloid was developed by J.W. Hyatt as a replacement material for the scarce and expensive ivory. At that time he certainly was not aware that he had introduced the first ever synthetically produced bioplastic. Celluloid is composed of a mixture of about 70 to 75 % by weight of cellulose di-nitrate and 25 to 30 % by weight of camphor. Over the years it has been displaced by mixtures of cellulose acetate (see extra frame) which are less combustible. Today, many other biopolymers and bioplastics are on the market, but there is still room for some bioplastics which started from the very beginning: Cellulose Acetate (CA) is marketed e.g as Biograde ® from FKuR, one of the most well-known applications of cellulose aceto butyrate (CAB) is the moulded handle on the Swiss army knife. A rather young, new casein-based polymer is marketed by Qmilk (cf. bM 05/2013). Univ.-Prof. Dr.-Ing. Christian Bonten is member of the Presidium of the Deutsches Kunststoffmuseum (German Plastics Museum) in Düsseldorf, Germany and Director of the Institut für Kunststofftechnik (IKT) in Stuttgart/Germany. Pic. 4: Clasp (celluloid as replacement for nacre) www.deutsches-kunststoff-museum.de “The secret to creating a transparent material that feels and looks like beautiful horn” (Original text in German, “ein durchsichtige materi (...) gleich wie schons horn”) “Take goat´s cheese or another low-fat cheese and leave it to simmer for a whole day. Then let it cool until a thick pastelike deposit forms. The white milky liquid floating above must be skimmed off. Pour fresh hot water over what remains, leave it to simmer again and stir so that the water separates from the paste. Repeat the process until the white substance no longer forms. What remains at the bottom of the pot is a substance that is viscous and transparent like horn and looks like curd cheese.” Father Seidel then picks up the thread: “Place the cleaned material in a well heated soapy solution and then press it into a mould. The filled mould has to be plunged into cold water, where it becomes as hard as bone and beautifully transparent.” And there you have “the ideal material for craftsmen.” Father Seidel adds: “If the process has been performed correctly, table tops, dinnerware and medallions can be cast from the material”. He continues: “But remember, the material must be moulded while still hot. Even when already moulded, it can still be shaped without being damaged. As soon as it has cooled down, however, bending or twisting will cause it to shatter like glass.” Pic. 5: Cigarette holder (casein as replacement for horn) Pic. 6: Belt buckle and buttons (Celluloid as replacement for horn) bioplastics MAGAZINE [04/14] Vol. 9 37

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