Interaction between matrix, semi-finished product and component properties of processing-optimized furan resin prepregs (FurPreg)

• Applicant: Dr.-Ing. Dennis Budelmann
• Subject Area: Polymeric and Biogenic Materials and Derived Composites ; Plastics Engineering ; Lightweight Construction, Textile Technology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 559990233

Furan resins based on furfuryl alcohols (polyfurfuryl alcohols) represent an ecologically significant alternative to petrochemical thermosets such as phenolic resins as they are entirely based on renewable raw materials. However, the great ecological and material potential of furan resins for their use as matrix materials in fiber-reinforced plastics (high resistance to heat, chemicals and corrosion, good mechanical properties, advantageous fire behavior, etc.) is not yet being exploited to an economically relevant extent. In particular, the release of water during curing associated with polycondensation is critical and leads to composite parts either being cured very slowly or exhibiting a high degree of porosity, which greatly reduces the mechanical performance. For the research project within the Walter Benjamin-Program, it is hypothesized that purposive pre-curing (B-staging) of furan resin-based semi-finished fiber products (prepregs and towpregs) can reduce the release of water and the associated component porosity to such an extent that components with high thermo-mechanical properties can be produced by short cure cycles. At the same time, however, processing-relevant properties are to be maintained or optimized. As a result, an optimization problem is faced that requires an interdisciplinary approach from polymer chemistry, production engineering and materials science using experiments and material modelling methods. Based on the presented research approach, the overarching project objective persists in the exploration of interactions during the development of furan resin-based prepregs and towpregs with optimized processing properties. This results in two sub-goals to be achieved for the successful implementation of the project: Sub-goal 1 consists in producing the processable semi-finished product by varying the catalyst content, toughening content and B-staging levels. Therefore, model resins made from furfuryl alcohol, maleic anhydride and epoxidized soybean oil are formulated and characterized. The resins are used in combination with a glass fiber reinforcement for the production of semi-finished products and transferred to a defined B-stage based on a modeling approach (cure kinetics). Sub-objective 2 comprises exploring the influence of variation on the processing and component properties achieved. For this purpose, drapability, tack and shelf life are characterized in the B-stage and curing cycles are derived. Cured laminates are used for mechanical characterization with regard to tensile properties, interlaminar shear strength and impact strength as well as for the analysis of porosity and fire resistance.

• DFG Programme: WBP Position