Gao L.-L.,Nanchang University |
Gao L.-L.,Engineering Research Center for Biomass Conversion |
Liu Y.-H.,Nanchang University |
Liu Y.-H.,Engineering Research Center for Biomass Conversion |
And 5 more authors.
Journal of Applied Polymer Science | Year: 2010
Bamboo residues were liquefied by using a solvent mixture consisting of polyethylene glycol 400 and crude glycerol (4/1, w/w) with 98% sulfuric acid as catalyst at 160°C for 120 min. The liquefied bamboo had hydroxyl values from 178 to 200 mg KOH/g and viscosities from 507 to 2201 mPa S. The obtained bamboo-based polyols were reacted with various amounts of polyaryl polymethylene isocyanate (PAPI), using distilled water as blowing agent, silicone as surfactant, and triethylenedi-amine and dibutyltine dilaurate as cocatalyst to produce semirigid polyurethane (PU) foams. The [NCO]/[OH] ratio was found to be an important factor to control the mechanical properties of PU foams. At a fixed [NCO]/[OH] ratio, both density and compressive strength of PU foams decreased with the increase of bamboo content. The micro-structure of PU foams indicates that [NCO]/[OH] ratios are important for cell formation and chemical reactions. The uniformity and cell structure of the foams are comparable to their corresponding compressive strengths. Moreover, the thermogravimetry analysis showed that all the semirigid PU foams had approximately the same degradation temperature of about 250 to 440°C. © 2010 Wiley Periodicals, Inc.
Lin D.,Engineering Research Center for Biomass Conversion |
Peng H.,Engineering Research Center for Biomass Conversion |
Ruan R.-S.,Engineering Research Center for Biomass Conversion |
Yu Z.-P.,Engineering Research Center for Biomass Conversion |
Liu Y.-H.,Engineering Research Center for Biomass Conversion
Xiandai Huagong/Modern Chemical Industry | Year: 2012
In this paper, hemicellulose was directly separated through the 1-allyl-3-methyl imidazolium room temperature ionic liquid ([Amim]Cl) from Moso bamboo. The structures of the hemicelluloses were elucidated by FTIR, thermal analysis, 13CNMR spectroscopy, content of neutral sugars and uronic acids. The results show that the room temperature ionic liquid treatment are effective on the separation of hemicelluloses from bamboo, and the components mixed with a small amount of pectin but not contain lignin and cellulose. The hemicellulosic fraction has a backbone of (1→4)-β-D-xylan and aere branched mainly through arabinose and 4-O-methyl-α-D-glucuronic acid, which arabinose at C-3 position of main chain and 4-O-methyl-α-D-glucuronic acid at O-2 position.