Increased adoption of composites in serial automotive production is limited by environmental and productivity issues related to existing resin systems. Styrenated polyesters and vinyl esters can result in unacceptable levels of residual VOCs (Volatile Organic Compounds) in cured composite laminates. Epoxy resins incur high costs due to poor productivity related to balancing cure speed, out-life, and resin cost. A new class of reactive diluent free vinyl hybrid resins will be reviewed offering fabricators the ability to overcome the deficiencies of existing resins. Thermosetting vinyl hybrid liquid and hot melt prepreg resins exhibit excellent mechanical properties and temperature resistance to 200°C. These resins are cured using a free radical cure mechanism with standard initiators. This allows significant processing advantages as compared to epoxy resins. Prepreg composites produced using vinyl hybrid resin can be stored at 25°C for 12 months and can be cured in 75 seconds at 150°C. Automotive headspace analysis demonstrated a VOC-free composite laminate. The first serial automotive application of the vinyl hybrid liquid resin is a composite floorboard in a 2014 model year vehicle. The composite floorboards are molded by Molded Fiber Glass Companies, Ashtabula, Ohio using the vinyl hybrid technology. The vinyl hybrid hot melt prepreg resins are in serial automotive production on the 2014 Chevrolet Spark Composite Electrical Battery Tray. Cytec Industries produces the battery tray fiberglass prepreg using the hot melt vinyl hybrid technology. The thermo-mechanical properties, production processes, and cure rates for these automotive applications will be reviewed and compared to existing resin systems.
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