However, larger quantities are necessary to be able to make reliable statements about the application options for these materials. Practical parameters in particular, such as mechanical properties, durability, look or feel, can only be assessed if the materials are processed under realistic conditions. This applies above all to thermoplastic materials, where the parameters during processing have a significant influence on the final product properties. Processing on practical machines requires at least a few hundred grams, but several kilograms of a material are preferable.
To be able to examine both the institute’s own developments as well as those commissioned by industry customers, and at a single location under suitable conditions, Fraunhofer LBF has set up a new kilogram laboratory, which enables the synthesis of a wide variety of substances at a kilogram scale, allowing them to be processed further at the in-house applications laboratory and provided for corresponding testing. Reactors and autoclaves with volumes of up to 20 liters are available in different versions, permitting reactions in temperature ranges from -80° to 250° Celsius, under inert conditions, at pressures of up to 60 bar or in a vacuum. Upscaling a reaction is more than just the multiplication of the reaction volume. Further aspects, such as a changed thermal transfer, secure handling of larger quantities of reactants and products, as well as preparation and post-processing, must be considered.
Kilogram laboratory bridges the gap
In the new Fraunhofer LBF kilogram laboratory, reactions such as the synthesis of polymers with special architectures can be carried out, which can be used as coupling agents or compatibilizers in order to improve mechanical properties, transparency, or adhesion to dissimilar materials. The use of gaseous monomers and reactants is also possible. As a result, thermoplastic elastomers made of styrene and butadiene can thus be produced by means of anionic polymerization and subsequent hydrogenation. Further synthesis examples include the production of aqueous polymer dispersions that can serve as binders, additives such as flame retardants or stabilizers, curing agents for epoxy resin, as well as the surface functionalization of fibers or (nano) fillers.
With its kilogram laboratory, Fraunhofer LBF can take its chemical solutions to special customer requests to a higher scale. The resulting products can either be processed further in LBF’s own applications laboratory or provided to customers for their own application tests. Customers that have already developed a product at the laboratory scale can then upscale the product to kilograms by the LBF to be able to assess their applicability.