Scientists at the DOE’s Oak Ridge National Laboratory invented a solvent-free production process that interconnects equal parts of nanoscale lignin dispersed in a synthetic rubber matrix.
What does it all mean? Well, the process produces a meltable, moldable, ductile material that’s at least 10 times tougher that ABS, a moldable thermoplastic polymer used in everything from kitchen appliances to car bumpers to even Lego bricks. ABL is also recyclable – it can be melted three times and still perform well.
In a heated chamber with two rotors, the researchers “kneaded” a molten mix of equal parts powdered lignin and nitrile rubber. During mixing, lignin agglomerates broke into interpenetrating layers or sheets of 10 to 200 nanometers that dispersed well in and interacted with the rubber. Without the proper selection of a soft matrix and mixing conditions, lignin agglomerates are at least 10 times larger than those obtained with the ORNL process. The product that formed had properties of neither lignin nor rubber, but something in between, with a combination of lignin’s stiffness and nitrile rubber’s elasticity.