INNOVATIONS | POLYURETHANES
Right:
Appliance insulation is another source of PUR foam waste
BT-Wolfgang Binder (Austria), with its Redwave trademark, offering expertise in the sensor-based smart sorting of end-of-life materials; WeylChem InnoTec (Germany), a contract development and custom synthesis company that will develop new building blocks for PUR; Ecoinnovazione (Italy), a research and consultancy firm in the field of lifecycle sustainability assessment; Ghent University (Belgium), which is described as being “at the heart of the breakthrough in the development of new molecules for recyclable materials that must be adapted to polyurethane chemistries”; KU Leuven (Belgium), which has a long history in catalysis expertise; Universidad De Castilla – La Mancha (Spain), which already has experience in recycling thermoset PU and has capabilities in scaling up chemical processes; and Ayming (France) which will provide project management support. The partners say PUReSmart will “develop
Covalently Adaptable Polyurethanes (CAPUs) based on fast reversible chemical bonds that enable the creation of cross-linked polymer networks reversible under certain conditions. Three different routes are under exploration. The choice of best candidates will be determined by their technical and economic feasibility. It will take time before these new PURs are industrially exploited and it will still need a full lifetime of these new products before full recycling takes place. There- fore, PUReSmart also aims at treating current PU materials. As a first step, the partners work on the sorting of EOL PUR-based materials in order to recover the raw materials (or their precursors) that have been used to produce these products. Detection methods will be developed in order to characterise and distinguish different PU foams. Once this is possible, sorting methodologies will be put in place in order to collect the different families in the purest form possible.” These sorted PUR families are then chemically
broken down. The final aim of the PUReSmart project is to recover the raw materials from existing PUR products on the market, and to use these raw materials to make a new generation of recyclable thermoset polyurethanes. An interim report from the project partners late
last year said the first CAPU elastomers have been obtained at Gent University and are being further evaluated, while work on the development of innova- tive sorting methods “moves ahead of schedule. Under the leadership of Redwave supported by Covestro and Recticel, detection methods were found to distinguish different PU foam families [which] were reorganised to enable an economical feasible but high quality chemolysis process.”
32 PLASTICS RECYCLING WORLD | January/February 2021
The chemical breakdown of current polyure- thanes is mainly investigated by KU Leuven, Covestro, Recticel and the University of Castilla-La Mancha. Covestro has been investigating the feasibility of a scale-up from laboratory scale to semi-industrial level to enable the handling of larger quantities of foams and to finally generate recycled polyol and recycled amine fractions. This will ultimately enable foaming trials with the recycled products. The project has already led to two patent
applications being submitted, one by Covestro and one by Recticel, related to the smart chemolysis process. The partners note that the recuperation of polyol
fractions “suffers from a non-sustainable use of raw materials (i.e. too much solvent has to be used and the recycled products can only be re-used at low percentages together with the virgin polyol stream in non-flexible foam applications). The PUReSmart project is working on a process with complete recovery of not only the polyol, but also of the isocyanate precursors (amines), which will hopefully lead to the first recycled isocyanate in the world.”
Foam-to-foam Since 2018, independent Spanish plastics research organisation Aimplas has been participating in the Foam2Foam project, the objective of which is also to obtain raw materials from polyurethane waste via chemical recycling (catalytic glycolysis in this case). This Spanish government-funded project involves three companies (Titan Recycling, Arcesso Dynamics and AMB Electrónica de Brescia) and two technol- ogy centres (Gaiker and Aimplas). It was launched in July 2018 and is due to end in July 2021. Three waste streams are being looked at: post-consumer PUR insulating foam from refrigera- tors, flexible foam from old mattresses, and
www.plasticsrecyclingworld.com
IMAGE: AIMPLAS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
