Polymer Synthesis

Material development based on polylactic acid (PLA)

Commercially available PLA-types are biodegradable thermoplastics used mainly in packaging due to their unique properties. However, further branches like automotive or textile industry linking achieved. The work conducted in our department consequently reflects the aforementioned points.

We work intensely on the development of second generation PLA types with properties optimized according to the aspired application. The focus of our research lies on investigations on the control of polymer architecture using synthetic methods like copolymerization, linking or branching of chains as well as transesterification. For example, easily producible block copolymer structures made of PLA and classical synthetic polymers like PMMA or polystyrene significantly improve properties like the heat deflection temperature (HDT ≥ 110 °C). Within another project we developed a technically feasible procedure employing reactive extrusion to obtain well-defined PLA stereo block copolymers. These PLA stereo block copolymers show comparable HDTs to PLA stereo complexes while exhibiting a broader variability of mechanical properties.

The technical center of the Fraunhofer IAP offers a miniplant that reproduces every step of the PLA process from lactic acid to the final polymer. Here, all intermediates can be synthesized in a tailored fashion, e.g. lactide with predefined enantiomeric excess up to 99.9% or functional PLA pre-polymers as reactant for reactive extrusion processes. Additionally, the developed synthetic routes can be investigated and modified or optimized with respect to their feasibility to adapt to the process.

Our work in this field is largely supported by our comprehensive experience in the analytics of PLA as well as its educts and intermediates.