Materials 60000
Materials 60000 copolymers by transesterification it is possible to achieve melting points of 200°C,” as Hans explains, “and the top of the list of possible variations is the stereocomplex type (scPLA) with melting points of 220-240°C.” And he adds: “It is so important to have the possibility to produce these different types of PLA because different applications ask for different properties and thus for different grades. Purac has produced D-lactic acid last year for the first time on an industrial scale and will dedicate a whole lactic acid plant to its production. “This is a real breakthrough,” says Ruud Reichert. Expanded PLA (particle foam) The first PLA producer that signed a partner contract to produce their own PLA is the Dutch company Synbra from Etten-Leur, a company that has been producing E-PS (expanded Polystyrene – particle foam) for many years. As customers from Synbra are increasingly looking for environmentally benign and sustainable solutions, Synbra wanted to find a biodegradable alternative based on renewable resources. Their newly developed E-PLA foam offers comparable or even better properties compared to E-PS (see a more detailed report on page 22). Market Potential … The picture on this page shows that the base scenario with the current PLA grades and the limited properties is not very attractive. Hans van der Pol predicts that the plastics industry will be involved to create more value added products and application areas. “You need that in the current stage in order to make PLA a sustainable business for the long term.” Considering this, Purac sees a potential of 500,000 tonnes by 2015. And that is clearly not only packaging. “We see a huge potential outside the packaging area. New value added applications are for example electronics, e.g. phones or flat screens, fibers (where scPLA is necessary for the processing but also for many applications), hot fill applications and even in the automobile sector, where we are seeing sustainability becoming an increasingly important trend,” says Hans van der Pol. Purac’s production sites Purac runs lactic acid plants in Brazil and in the USA as well as in in Netherlands and in Spain. At all these locations Purac also produces lactic acid derivatives such as salt solutions, esters or powder products. End of 2007 in Thailand a new very efficient plant for L(+) lactic acid with a capacity of 100,000 tonnes/a was opened. This enabled Purac to convert its plant in Spain from L(+) to a dedicated factory for the fermentation of D(-) lactic acid Volume [Mt] 50000 40000 30000 20000 10000 0 2005 2010 and lactides. “This is now the first step, but we expect that by 2015 our partner model will result in factories where PLA production from sugar is integrated with lactic acid fermentation and lactide production on a 100 kton scale” comments Hans van der Pol. www.purac.com www.sulzerchemtech.com www.synbra.com 2015 PLA market forecast with plastics technology With Plastics Technology - High added value - Positive PLA margins Base Scenario - Low added value appl. - Negative margins for PLA producers Plastics Technology is critical factor for sustainable PLA growth 1: Lactic acid molecules exist either in a L(+) Form (levorotatory form (the (+)-form) or in a D(-)/form dextrorotatory form (the (-)- form). The L(+) form tends to transform into D(-) in a process called racemization. Purac is successful in reducing the racemization to a minimum in order to achieve very pure L and D-lactides. Purac produces pure L-lactides (or L(+) lactides consisting of two L(+) isomers of lactic acid) and pure D-lactides (or D(-) lactides consisting of two D (-) isomers of lactic acid) (with a purity of about 99%). Lactides consisting of an L(+) and an D(-) isomer are called meso-lactices. PLLA is obtained by polymerization – that is connecting the lactic acid molecules – of very pure L-lactide. Similarly, PDLA is obtained from D-lactide monomer. Stereocomplex PLA is a special kind of PLA with a melting point of more than 200°C. It is made by mixing PLA and PDLA in a 1 to 1 ratio. Compare it with 2 component glue: the individual components are soft and plastic, while the mixture hardens to become a strong and stiff material. 20 bioplastics MAGAZINE [01/09] Vol. 4
Foam Coloured loose fill – fun for young and old Coloured loose fill packaging chips have been available for quite a while already. Just before the Christmas period German discounter Aldi sold a product under the brand name Bioplay. The box, marked ‘Automobilset’, showed pictures of cars, traffic lights etc. The coloured loose fill chips in the box were made from pure starch rather than the usual polystyrene foam and were supplied to Aldi by German Pantos Produkt & Vertriebsgesellschaft. safe, being made of starch and coloured with food dyes. Even Tiziano Mori, cover-hero of this issue of bioplastics MAGAZINE and bar-tender at the European Bioplastics booth, loved the coloured chips. “I was amazed at all the bioplastics products I saw during my job at interpack. But these coloured chips were the biggest fun for me” he said. During interpack 2008 (Düsseldorf, Germany, April 2008) two large groups of kindergarten kids visited the special show ‘bioplastics in packaging’. Sponsored by Novamont, the children were given loads of coloured loose fill chips to play with, and discovered this as a kind of toy - totally (Photo: Philipp Thielen) bioplastics MAGAZINE [01/09] Vol. 4 21
