Rheological Properties Of Salix Liquefied Products And Properties Of Foamed Materials

In this paper,the biomass resource-Salix psammophila was used as a raw material.Salix wood powder was liquified by a catalyst to obtain a liquefied product,and its rheological properties were analyzed.The product of Salix liquefied with isocyanate,cross-linking agent,and foaming agent were used to prepare rigid polyurethane foam,and its cell structure,thermal stability,crystallization and combustion properties were studied.1.Salix,polyol,concentrated sulfuric acid were chemically synthesized to obtain liquefied products.In this paper,single factor and orthogonal test methods were used to optimize the liquefaction process.The rheological properties of the prepared Salix liquefied product were tested and analyzed using a rotary rheometer.Salix liquefied products take viscosity as reference factor,combined with liquefaction rate,the best process conditions are reaction time 70 min,reaction temperature 170?,catalyst dosage 5%.Under the best process conditions,when the shear rate is 78.87 s-1,the viscosity is the largest,which is 0.26 Pa·s.According to FTIR analysis,the cellulose in the liquefaction was largely degraded,and the hemicellulose and lignin were partially degraded.2.The rheological properties of liquefied products were tested in this paper.Salix liquefied products are shear thinning and belong to pseudoplastic fluid.The storage modulus(G')and loss modulus(G")increase with the increase of the complex frequency(?*).When the liquefaction conditions are set to 70 min,160?and 4%,the storage modulus,loss modulus,and complex viscosity of the liquefaction are the largest,respectively,and the reaction degree is better.The viscous activation energy(?E)of the liquefied product depends not only on the temperature,but also on the shear rate(?).When the amount of catalyst is 4%,its liquefaction compatibility and uniformity are good,and long branched chains appear in the polymer molecules.SEM analysis shows that when the rheological parameter value of the liquefied product is large,the cells of RPUF are relatively dense.3.In this test,triethanolamine(TEOA)and trimethylolpropane(TMP)were added to the preparation of rigid polyurethane foam.The micro structure,thermal stability,crystallization and combustion performance of the samples were tested by SEM,thermogravimetric analyzer(TG),X-ray diffractometer(XRD)and cone calorimetry.As a result,it was found that with the addition of triethanolamine and trimethylolpropane,the cell density of polyurethane foam can be increased,the thermal stability is improved,but the crystallinity is reduced.RPUF/TEOA and RPUF/TMP products have better flame retardant performance than RPUF products.