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Cassava residue was liquefied by using ethylene glycol (EG), ethylene carbonate, propylene carbonate and polyethylene glycol (molecular weight: 400 g/mol) as the liquefaction reagent respectively at the temperature of 130–170 °C with sulfuric acid as the catalyst. The influences of liquefaction parameters, such as the type of liquefaction reagents, mass ratio of EG/cassava residue, liquefaction temperature and time on the properties of the products were discussed. The optimum liquefaction conditions were obtained when the mass ratio of EG/cassava residue was 6:1 (w/w), the liquefaction temperature was 150 °C, the liquefaction time was 3 h and the mass fraction of concentrated sulfuric acid/EG was 2.5wt%. The hydroxyl numbers and residue content of the liquefied products at optimal conditions were 1 137 mgKOH/g and 0.43%, respectively. FT-IR spectrum showed that the liquefaction product of cassava residue was polyether polyol and could be used to prepare polyurethane material or alkyd resins.

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.

Citric acid modified cellulose waste (CMCW) was prepared via esterification 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 fit 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.

Citric acid modified mixed hardwoods powder (CMH) was prepared as a biosorbent to remove copper ions and methylene blue (MB) from aqueous solution by batch techniques. FT-IR and XRD were used to characterize the biosorbent. The effects of initial pH value, biosorption temperature, contact time, and initial adsorbate concentration on the biosorption capacities and adsorptivity of Cu2+ and MB onto CMH were investigated. The results showed that CMH exhibited excellent biosorption characteristics for Cu2+ and MB. The maximal biosorption capacity of Cu2+ and MB onto CMH was 165.0 and 237.4 mg/g at 20 °C, respectively. The biosorption kinetics studies indicated that Cu2+ and MB biosorption followed the pseudo-second-order model. The biosorption may be controlled by external intraparticle diffusion mass transfer during the whole biosorption process. Furthermore, the biosorption-equilibrium can be well described by Langmuir and Freundlich isotherm models.

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.

Wood–Ceramics are prepared from a shaped mixture of rice husk and high-temperature coal tar pitch by pyrolysis at different temperatures. Subsequently, the wood–ceramics are modified by pyrolysis of different mixture precursors with adding lignin. The effect of pyrolysis temperature, lignin content and lignin types on the microstructure, yield, volume shrinkage, open porosity ratio and bending strength of the wood–ceramics is discussed, respectively. The results show that the microstructure, volume shrinkage ratio, and bending strength of wood–ceramics are significantly dependent on the pyrolysis temperature, lignin content and types. When the pyrolysis temperature increases from 500 to 1200 °C, the (002) crystal planes peaks of the wood–ceramics move to a higher diffraction angle and the intensity of these peaks increase. The volume shrinkage ratio and bending strength of the wood–ceramics increase from 41.2 to 55.5 % and 10.2 to 31.2 MPa, respectively. Moreover, the open porosity ratio first decreases from 35.6 to 26.2 %, and then increases to 30.1 %. The enzymatic hydrolysis lignin (EHL) plays an important role in improving the order and graphitization, porous content and open porosity of the EHL-modified wood–ceramics, whereas the lignosulfonate causes the bending strength of the lignosulfonate-modified wood–ceramics to decrease.

Novel biosorbents, graft copolymers, were prepared via Mannich reaction from enzymatic hydrolysis lignin with glycine and cystine, respectively. The element content, FT-IR and fluorescence spectra, relative viscosity, and particle size of the copolymers were systematically investigated. Furthermore, effects of initial pH, ionic strength, temperature, contact time and initial metal ion concentration on the biosorption capacities of Cu(II) and Co(II) ions onto the copolymers were studied using batch sorption technique. It was found that the copolymers exhibited excellent biosorption characteristics for Cu(II) and Co(II) ions. The sorption kinetic data can be described well with a pseudo-second-order model, and the equilibrium data can be fitted well to the Langmuir and Freundlich isotherm for Cu(II) and Co(II) biosorption process, respectively. Surface complexation and ion-exchange modeling were performed to elucidate the biosorption mechanism involved because surfaces of the copolymers contained three main types of acid/base sites from the amino acid grafted copolymer units.

Electrically conductive hollow nanospheres with an average diameter between 100 and 200 nm were prepared via a one-step polymerization of aniline in the presence of lignosulfonate (LS) by using ammonium persulfate (APS) as the oxidant. The LS concentration and molar ratio between APS and aniline, the temperature and time for polymerization were adjusted to optimize morphology, structure and electrochemical properties. Uniform hollow nanospheres are best obtained at a concentration of 18 wt% of LS, at a polymerization temperature at 25 °C, at an APS/aniline molar ratio of 1:1, and at a polymerization time of 1 to 12 h. This kind of preparation of nanospheres represents a simple and general route to polymer hollow nanospheres of controllable size, high stability, and optimizable electroconductivity.

Enzymatic hydrolysis lignin (EHL), isolated from the enzymatic hydrolysis residues of the biomass, was liquefied using the mixed solvents of polyethyleneglycol (PEG) and glycerol at the temperature of 130-170°C with sulfuric acid as a catalyst. The influences of liquefaction parameters, such as the molecular weight of PEG, mass ratio of sulfuric acid to EHL, liquefaction temperature and time, and mass ratio of liquid (liquefying cosolvent) to solid (EHL) on the residue content and hydroxyl number were discussed. The FT-IR spectrum result showed that the liquefaction product of EHL was polyether polyol. The hydroxyl number of the liquefaction product was 80-120 mgKOH/g higher than that of PEG.

A novel spherical lignin-base adsorbent (L-BAA) was prepared by reversed phase suspension polymerization technique. The L-BAA was characterized by element analysis and FTIR spectra. The modified lignin beads (L-BAA) were used to adsorb Cr (VI) from aqueous solution. The effects of the contact time, the pH value, the initial concentration and the temperature on the adsorption were investigated. It was found that Cr (VI) adsorption was greatly dependent on the pH and temperature of the Cr (VI) aqueous solution. When the temperature was 25 °C, the maximum capacity of 417.26 mg/g was attained at 0.82 pH. The adsorption capacity is better than other reported adsorbents. All of the end pHs were higher than the initial pHs. The results indicated that the adsorption belongs in ligand exchange mechanism. High temperature promoted adsorption, the high capacity 473.80 mg/g was attained at 35 °C and the adsorption efficiency was up to 94.76 %. This result indicated that the adsorption was not only physical but also chemical, which could be proved more by the FTIR spectra, and the adsorption was an endothermic progress.

Emulsified asphalts are popular at recent years for saving energy to melt solid asphalt. Emulsifier is very important for emulsification of asphalt. Enzymatic hydrolysis lignin modified amine (EHLA) was synthesized by Mannich reaction of enzymatic hydrolysis lignin (EHL) with formaldehyde and triethylene tetramine (TETA). The structures of the product was analyzed by FT-IR, and the influence of process parameters such as the molar ratio of formaldehyde to TETA, the reaction temperature and time were discussed. According to the results, the optimized technological conditions were as follows: the reaction temperature was 80 °C, the molar ratio of formaldehyde to TETA was 1.6∶1, reaction time was 3 h, and the weight of lignin was 25 g. The result of emulsification shows that EHLA could be an effective and slow set cationic asphalt emulsifier.

Walnut shell high boiling solvent lignin (WHL) was prepared by high boiling solvent method, and its structural information could be obtained by using chemical composition analysis, infrared spectroscopy, and NMR spectroscopy. The C 9 -formula of WHL, C 9 H 8.95 O 2.37 (OCH 3 ) 0.72 , was calculated by the experiment data. IR spectrum showed that the syringyl and guaiacyl groups were clearly existed in WHL. The 1H-NMR spectrum of WHL also indicated the aliphatic and aromatic methoxyl groups with relative intensity ratio situated at 3.5–3.8 and 3.8–4.0 ppm, respectively. The β-O-4 bond and β-5 carbon-carbon linkage were found to be the major linkages between WHL units from the result of 13C-NMR spectrum.

In this paper the Mannich reaction product of dimethylamine, acetone and formaldehyde was grafted onto hydroxymethylated lignin to form a lignin-base cationic polyelectrolyte (L-DAF). L-DAF samples with different cationic strengths and molecular weights were synthesized and characterized. Their performance as a cationic flocculant in removing three anionic azo-dyes (Acid Black, Reactive Red and Direct Red) from simulated dye wastewater was evaluated. The removal of anionic dyes by L-DAF was ascribed to two simultaneous mechanisms, which included coagulation by charge neutralization and flocculation by bridging. There was a different optimum dose of flocculant for each dye wastewater, at which dye removal can reach above 95%. Furthermore, a longer settling time and a lower solution pH increased the efficiency of the decolorization process. During the treatment, more than 89% of chemical oxygen demand (COD) reduction was achieved with sludge production being less than 5.4%.

Lignin isolated from enzymatic hydrolyzed cornstalks (EHL) is a renewable natural polymer, and rubber is one of the most important polymer materials. The application of EHL in rubber industry is of great significance. The influence of EHL and antioxidant RD on the vulcanizing characteristics, thermal oxidative aging stability under free condition, and water extraction resistance of styrene‐butadiene rubber (SBR) were investigated. The effect of EHL/antioxidant D composite antioxidant on the thermal oxidative ageing of SBR was also evaluated. Results showed that the protection of SBR from thermal oxidative aging by EHL/antioxidant D composite antioxidant was superior to that of antioxidant D. This is because EHL molecules have hindered phenol group and have excellent auxiliary antioxidant role with antioxidant D. Moreover, the influence of EHL on the vulcanizing characteristics of SBR compounds was better than that of antioxidant RD, and EHL can reduce the cure rate and increase the optimum cure time. It is because that the EHL molecules have hindered phenol group and methoxy group, which can form a special structure to capture free radical and terminate the chain reaction. The retained tensile strength of SBR compounds with EHL was similar to that of the samples with antioxidant RD, while the retained elongation at break of SBR compounds with EHL was higher than that of the samples with antioxidant RD. In addition, the SBR compounds with EHL have a good water extraction resistance property, which was similar to the samples with antioxidant RD. This is because EHL have large molecular weight, good stability and low solubility in water. In conclusion, due to the low price, abundant resources, non‐toxic and pollution‐free, etc., EHL will have broad application prospect.

Graft copolymerization of maleic anhydrideon (MAH) onto enzymatic hydrolysis lignin (EHL) was carried out with sodium hydroxide aqueous solution as solvent and potassium persulfate‐sodium bisulfite (K2S2O8−NaHSO3) as initiator. The graft ratio and graft efficiency of the copolymer were systematically investigated through changes in the reaction temperature, reaction time, MAH concentration and initiator concentration. The grafted copolymer was further characterized by FTIR and UV‐visible spectroscopy. It was found that the graft ratio and graft efficiency varied significantly with the above‐mentioned reaction parameters. The optimum conditions for the graft copolymerization were as follows: initiator K2S2O8−NaHSO3 with a quantity 2.5% of lignin, MAH: EHL (mass fraction) = 0.12, reaction time was 3.5 h and temperature at 60° C. In the scope of this experiment, the graft ratio and graft efficiency were respectively obtained up to 5.34% and 80.08%. The fact verified that EHL has better chemical activity.

Polyaniline nanofibers with high yield (93%) have been synthesized by an unstirred polymerization of aniline in aqueous acid media with ammonium persulfate as an oxidant in the absence of any template, dopant or surfactant. The morphology, structure and electrical conductivity of the nanostructural polyaniline prepared under different conditions were characterized by means of scanning electron microscopy, FTIR, UV-vis and four-probe techniques. It was found that branched network-like polyaniline nanofibers were prepared without any mechanical stirring, whereas irregular and rodlike structural polyaniline samples were obtained with mechanical stirring under the same reaction conditions. Flowerlike polyaniline microspheres of ca. 3.5 μm in outer diameter, which were constructed with nanostructural polyaniline lamellar by self-assembly process, were synthesized during the polymerization at 0 °C for 72 h. The as-synthesized HCldoped polyaniline nanofibers have good room-temperature electrical conductivity of 5.0 S/cm.

Phenol-formaldehyde (PF) adhesives modified with enzymatic hydrolysis lignin (EHL) were synthesized by a one-step process. The phenol component of the PF adhesives was partially substituted by EHL extracted from the residues of cornstalks used to produce bio-ethanol. The EHL-PF adhesives were used to prepare plywoods by hot-pressing. The pH value, viscosity, solid content, free phenol content, free formaldehyde content and brominable substance content of EHL-PF resins were investigated. The bonding strengths of the plywoods were determined, and the influences of the replacement percentage of phenol by EHL (a) and the NaOH content (b) on the properties of the adhesives were investigated. The results showed that the performance of the modified adhesives and the plywoods glued with them almost met the Chinese National Standard (GB/T 14732-2006) for first grade plywood when 20 wt% of the phenol was replaced by EHL.