Polyurethane foams extended with corn flour
1991
Cunningham, R.L. | Carr, M.E. | Bagley, E.B.
Five levels of unmodified corn flour (5, 10, 20, 30, and 40%, based on weight of polyether polyol) were evaluated as fillers-extenders in rigid polyurethane foams. Densities of the flour-filled and control foams were similar (0.025-0.026 g/cm3) except for the foams containing 10% flour (0.029 g/cm3). The moisture in the flours at the various levels of addition appeared to have a significant effect on the structural formation of the foams. Force-deformation curves of foams with 5 and 10% flour were similar to those curves of the controls. Thermal conductivity of the foam filled with 10% flour was slightly lower (thus having greater insulating value) than were the values for the foam filled with 5% flour or the control foam (0.0232 versus 0.0242 W/m.cntdot.K) (0.161 versus 0.168 BTU in./[ft2.cntdot.hr.cntdot..degree.F]). Foams containing 5 and 10% flour did not increase more than 5% in volume when subjected to thermal or humid conditions for 14 days. At the 40% level, foams expanded 14 and 16% under thermal and humid conditions, respectively, after 14 days.
显示更多 [+] 显示较少 [-]