Comparative Effect of Biofillers in pMDI Resin Performance

This study investigated the feasibility of using wood flour (WF) as a partial substitute in polymeric methylene diphenyl diisocyanate (pMDI) resin and compared its performance with soy flour (SF) substituted in pMDI resin. The physical and mechanical properties of experimental particleboards made with WF and SF substituted in pMDI resin at different substitution percentages were evaluated. The viscosity for the WF at different substitution ratios (5%, 10%, 20%, and 30%) ranged from 314.7 to 6,256.3 cP, whereas SF-substituted resin ranged from 249.7 to 1,291.8 cP. During the production of the boards, it was observed that because of the high viscosity of WF substituted in pMDI resin above 10 percent, it was exceedingly difficult to apply it through spraying and brushing, either to wood particles or veneers. Dimensional stability test results established that the incorporation of SF assisted in mitigating board thickness swelling. The results from the study showed that panels made with SF substituted in pMDI resin at 5 and 10 percent exhibited the overall best performance in all the properties considered compared with panels made with WF substituted in pMDI resin.