Abstract:

Rice straw was smashed into powder with the particle size of 250-590 μm. Catalytic liquefaction tecnology under atomosphere pressure and heating was used to liquify the straw powder. Subsequently, polyurethane rigid foam(PURF) was produced by physical foaming method of liquified rice straw as material and PAPI with pentamethyl diethylenetriamine(PC5) and N, N-dimethyl cyclohexlemine(PC8) as co-catalyst and n-pentane as physical blowing agent. And the water-blown polyurethane foam was prepared as compare. The optimal conditions for PURF production was mass ratio of PC5 and PC8 4:5, foam stabilizer dosage 4%, and blowing agent n-pentane dosage 15%, the tensile strength and compressive strength of the obtained PURF were 347 kPa and 181 kPa. The FT-IR and scanning electron microscope(SEM) were used to compare two kinds of PURF. And the results showed that compared with the water-blown polyurethane foam, the obtained PURF had lower isocyanate concentration, lower open porosity and more superior mechanical properties.

Key words: rice straw, liquefaction, polyurethane foam, blowing agent