Polymer composites contribute significantly to technological advances and more important, to increased resource efficiency and hence to a sustainable development. Today, most polymer composites are produced from petrochemical resources. However, initiatives of the European Union (EU) towards a resource efficient and sustainable low-carbon economy require the development of new materials and new consumer products from European biomass, avoiding the need for fossil-based inputs. In terms of polymer composites, this transition into bio-based industry while meeting the EU’s plastics circular economy directives requires interdisciplinary research covering complex interrelations of bio-based polymer building-blocks, polymer-physical performance, efficient processability and recyclability. With respect to these aspects, the lecture will address the development of highperformance epoxy resins based on renewable resources. Specific focus is on obtaining cost-efficient resin systems with a bio-based carbon content of 100% which exhibit properties that are competitive to those of conventional resin systems. Application potentials and challenges, recyclability and future perspectives are outlined.