Microstructure and Properties of Woodceramics Prepared from Lignin-modified Phenol-formaldehyde Resin

Novel woodceramics were successfully fabricated by enzymatic hydrolysis lignin （EHL） modified phenol-formaldehyde resin and woodpowders. The microstructure of woodceramics was investigated by FT-IR, X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The effects of EHL-modified PF resin on the properties of woodceramics, such as the weight loss ratio, volume shrinkage ratio, open porosity, bending strength and compressive strength, were studied. The experimental results showed that EHL modified woodceramics had a uniform porous structure. EHL-modified PF resin played an important role in the properties of woodceramics. With the increase of EHL-modified PF resin content, the open porosity, weight loss ratio and volume shrinkage ratio of woodceramics increased, but the bending strength and compressive strength decreased.

Biosorption of Methylene Blue by Chemically Modifi ed Cellulose Waste

Citric acid modifi ed cellulose waste（CMCW） was prepared via esterifi cation and used as a low-cost biosorbent for the removal of methylene blue（MB） from aqueous solutions. The effects of biosorbent concentration, initial pH of MB solution, biosorption temperature, contact time, and initial MB concentration on the biosorption of MB were investigated using batch biosorption technique under static conditions. The experimental results showed that CMCW exhibited excellent biosorption characteristics for MB. The maximum biosorption capacity of MB was up to 214.5 mg/g at an adsorption temperature of 293 K. The removal rate of MB onto CMCW reached the maximum at pH〉4 and the biosorption reached an equilibrium at about 50 min. The kinetic data can be described well with the pseudo-second-order model and the isotherm data was found to fi t the Langmuir isotherm with a monolayer adsorption capacity of 211.42 mg/g. The biosorption appears to be controlled by chemisorption and may be involved in surface adsorption and pore diffusion during the whole biosorption process.

Preparation of Bio-polyols by Liquefaction of Hardwood Residue and Their Application in the Modification of Polyurethane Foams

Hardwood residue（HR）,a byproduct of paper industry,was liquefied by using polyethylene glycol 400（PEG400） and ethylene carbonate（EC） as the liquefaction solvents,and concentrated sulfuric acid as the catalyst to produce bio-polyols（HRLP）,which were used to synthesize polyurethane（PU） foams.The effects of conditions on the properties of HRLP and modified PU foams were investigated and the mechanism of biomass liquefaction was discussed.The optimum conditions of liquefaction were obtained as follows： reaction temperature of 160 °C,reaction time of 60 min,ratio of PEG400/EC of 8：2（w/w）,and ratio of liquid/solid of 5：1（w/w）.The characterization of HRLP modified PU foams suggested that HRLP could partially replace the petroleum polyols to synthesize PU foams.With the increase of the replacement percentage of HRLP,the apparent density and compressive strength of the foams increased firstly,and then decreased.Meanwhile,the thermal stability was improved slightly.