Development of a Flame-Retardant Injection Molding Material Made of PLA with High Heat Resistance and Impact Resistance for Technical Products
10 Nov 2022
In technical applications and markets with high requirement profile, such as electronics products, transportation or even the construction sector, bioplastics have so far hardly been represented to any significant extent. Besides economic aspects main reasons for this are inadequate properties for technical products. Therefore the material properties play an important role in its market success for technical applications. For example, plastics for technical products usually have to meet a whole series of minimum requirements, such as high heat resistance, high toughness and low flammability. Bioplastics, such as polylactic acid (PLA), do not fulfill these requirements. Despite intensive research and development in recent years, PLA still does not have a marketable property profile for technical injection molding products. In a research project funded by the German Federal Ministry of Food and Agriculture, the Fraunhofer Institute UMSICHT, together with Evonik Operations GmbH, the Institute for Plastics Processing at RWTH Aachen (IKV) and FKuR Kunststoff GmbH, was able to develop formulations with simultaneously improved impact strength, heat resistance and flame retardancy. In addition to material development, the processing parameters were investigated, to reach an economic manufacturing process via injection molding. The research consortium was able to identify important cause-effect relationships and corresponding materials were produced on an industrial scale. The property profile of the developed materials ranges from heat deflection temperatures above 100 °C, charpy impact strength of over 50 kJ/m2 and a flame retardancy category V0 in the UL 94 test. Through targeted additives and the adjustment of the crystallization behavior of the PLA-based materials, it was possible to produce real components in cooperation with partners from the electronics industry.