Epoxidized sucrose soyate-A novel green resin for crop straw based low density fiberboards

A study was conducted to evaluate the mechanical properties of low density fiberboard produced with combinations of two fibers soybean straw (Glycine max), and wheat straw (Triticum aestivum) and two resins methylene diphenyl diisocyanate (MDI) and epoxidized sucrose soyate (ESS) resin as binders. ESS is a high performance, soybean oil based epoxy that has shown promise as a highly biobased adhesive. Six formulations of panels were produced using various combinations of straw and resin binder. Mechanical testing of sample boards was conducted using ASTM standard D1037-12. Test results showed that type of resin did not influence soy straw or wheat straw board's stiffness and strength properties but had a major impact on water resistance, screw withdrawal strength and internal bond strength. The study demonstrated the potential of ESS as a novel binder for fiberboard system if a suitable crosslinker and catalyst is utilized. It also showed that increasing ESS content over 50% in a MDI blend lowered the performance characteristics of boards. However, analytical testing of the resin systems showed limited reactivity between ESS soyate and MDI, indicating other compatible resin chemistries should be explored for achieving superior board properties. Overall, a resin blend with 25-50% ESS in MDI appears favorable for low density fiberboards. ESS can be a promising bio-based resin as it has the potential to meet California Air and Resources Board (CARB) standards while providing acceptable properties as an adhesive.