Polyols from Microwave Liquefied Bagasse and Its Application to Rigid Polyurethane Foam

Abstract

Bagasse flour (BF) was liquefied using bi-component polyhydric alcohol (PA) as a solvent and phosphoric acid as a catalyst in a microwave reactor. The effect of BF to solvent ratio and reaction temperatures on the liquefaction extent and characteristics of liquefied products were evaluated. The results revealed that almost 75% of the raw bagasse was converted into liquid products within 9 min at 150 °C with a BF to solvent ratio of 1/4. The hydroxyl and acid values of the liquefied bagasse (LB) varied with the liquefied conditions. High reaction temperature combining with low BF to solvent ratio resulted in a low hydroxyl number for the LB. The molecular weight and polydispersity of the LB from reactions of 150 °C was lower compared to that from 125 °C. Rigid polyurethane (PU) foams were prepared from LB and methylene diphenyl diisocyanate (MDI), and the structural, mechanical and thermal properties of the PU foam were evaluated. The PU foams prepared using the LB from high reaction temperature showed better physical and mechanical performance in comparison to those from low reaction temperature. The amount of PA in the LB has the ability of increasing thermal stability of LB-PU foams. The results in this study may provide fundamental information on integrated utilizations of sugarcane bagasse via microwave liquefaction process.

Isolation and characterization of cellulose nanofibers from bamboo using microwave liquefaction combined with chemical treatment and ultrasonication

“…In recent years, microwave energy has been applied in the liquefaction of lignocellulosic biomass to enhance the biomaterials industry (Xie, Hse, Shupe, Qi, & Pan, 2014b;Xie, Zhai, Hse, Shupe, & Pan, 2015).…”

Agricultural and Forest Residues towards Renewable Chemicals and Materials Using Microwave Liquefaction

“…The results confirmed that sulfuric acid was also a good choice in the liquefaction of lignin [61]. Sulfuric acid was found to be the most influential factor on the conversion of lignin compared to time and lignin concentration [60]. Furthermore, sulfuric acid was more efficient for the production of monophenolic products from liquefaction of lignin than the zeolite and FeS binary catalyst [62].…”

“…A catalyst has been used in almost every liquefaction process using either conventional or microwave heating. In the liquefaction of most lignocellulosic biomass using microwave energy, sulfuric acid has been identified as a prevailing catalyst [57][58][59][60]. A variety of acids (sulfuric acid, hydrochloric acid, phosphoric acid, and formic acid) have been used in the microwave liquefaction of the components of lignocellulosic biomass.…”

“…Various lignocellulosic biomass types such as poplar, southern pine, bamboo, bagasse, agricultural residues, and lignin have been microwave liquefied in alcohol solvents to produce PU foams. As shown in Figure 2, under different liquefaction conditions (the mass ratio of bagasse flour and biocomponent polyhydric alcohol was 1 : 2, 1 : 3, and 1 : 4 and the temperature was 125°C and 150°C), all the synthesized PU foams were of rigid type and the foam was darker in color with the addition of the liquefied bagasse [49,60,[74][75][76][77][78][79][80]. The properties of the fabricated biobased foams from microwave-liquefied products were largely dependent on the biomass type, heating methods, and liquefaction conditions.…”

Novel Synthesis of Core-Shell Biomaterials from Polymeric Filaments with a Bioceramic Coating for Biomedical Applications

“…the degree of polymer degradation also increases. Figure 4a presents the TPU thermogram, where a mass loss of 100% was recorded at around 356 • C, suggesting a low thermal stability [60]. The complete degradation of the polymer is accomplished in a singular step, in the range 380-430 • C. In addition, at lower temperatures, down to 380 • C [61], the DTG curve presents a mass loss of only 2%.…”