Nanocrystalline cellulose (NCC) is a promising nanofiller for reinforcing chitosan (CTS) film. The flocculation of the NCC suspension in acidic CTS solution is the key problem that makes many properties such as the tensile strength bad. A derivative of nanocellulose, namely cationic dialdehyde cellulose (CDAC), is synthesized in the current study to avoid the flocculation. A CDAC suspension is prepared in a successive oxidation-reductive amination process of NCC. The oxidation of NCC led to smaller rod-like nanocrystals with a reduced crystallinity. The suspension with 1.0% CDAC is well mixed with 1.0% CTS solution. Besides, the tensile strength and anti-swelling properties of CDAC-filled CTS nanocomposite films are improved because of the uniform distribution of CDAC in the CTS matrix plus the intermolecular chemical cross-linking between CDAC and CTS. The tensile strength of CTS-based nanocomposite film with 12% CDAC is about 58.4% higher than that of the pure CTS film.

•Cellulose nanocrystals were grafted with polystyrene via SI-ATRP.•The functionalization of the CNC surface favored its dispersion in the PMMA matrix.•The thermal and mechanical properties of PMMA were improved with reinforcement of CNC.•The transparency of nanocomposites was particularly presented.Cellulose nanocrystal (CNC) is a promising strengthener but is used limitedly since its poor compatibility with organic materials. The graft polymerization of styrene via surface-initiated atom transfer radical polymerization (SI-ATRP) of cellulose nanocrystal is adopted to modify its thermo-stability and compatibility. The modified crystals have been dosed into polymethylmethacrylate (PMMA) nanocomposites by the solution casting. The polymeric layer on the surface of CNCs should improve the thermal stability of CNCs, and provide significant dispersibility and compatibilization for the nanocomposites. Thermogravimetry analysis proved that the initial degrade temperature of CNC was increased 50 °C with the modification. The scanning electronic microscope showed that the modified CNCs homogeneously dispersed in PMMA matrix. Breaking strength and elongation at break of the composites were improved, which was attributed to the reinforcement of CNCs modified with styrene. Transmittance of nanocomposite films measurement showed that the transmittance of PMMA/1%CNC was almost close to that of pure PMMA.

Cellulose, one of the most abundant and useful natural resources from products of forests, has become increasingly important because of its conversion to bio-ethanol. Yet, the low yield of the conversion is the key problem that should be solved. Microcrystalline cellulose was chemically modified with 2,4-dianilino-6-chloro-1,3,5-triazine to increase the yield of hydrolysis of cellulose for high glucose generation. The modifier, 2,4-dianilino-6-chloro-1,3,5-triazine, was synthesized from 2,4,6-trichlorine-1,3,5-triazine and aniline, and the chemical structure of the modifier was determined by Fourier transform-infrared, nuclear magnetic resonance and mass spectrometry techniques. The structure of the modified microcrystalline cellulose was characterized by Fourier transform-infrared spectrometry and wide-angle X-ray diffraction techniques. The hydrolysis of the modified microcrystalline cellulose had been studied and the yield of the reducing sugar reached the highest when the relative molar percentage of 2,4-dianilino-6-chloro-1,3,5-triazine to the cellulose (based on the remained glucose unit) was about 30 %. The change of the crystalline structure of cellulose by chemical modification, which was suggested by wide-angle X-ray diffraction spectra, was propitious to the hydrolysis of cellulose. Furthermore, the yield of hydrolysis varied with the loading of the modifier which was due to the change of the crystalline structure of the modified cellulose. It might be a probable mechanism of yield improvement via modification that was verified by the calculated result of crystalline index and crystallite size.

In aqueous solution a cationic copolymer, poly (β-CD–AA–DMC) was synthesized via free radical copolymerization of acrylic acid (AA) esterified β-CD (β-CD–AA), and a cationic monomer [2-(Acryloyloxy)ethyl] trimethyl ammonium chloride (DMC). The copolymer's structure, morphology and thermal stability were demonstrated by FT-IR, 1H NMR, SEM and TGA analysis. The flocculation properties of the copolymer were evaluated by the decolorization solutions of two reactive dyes using a jar test method. The decolorization efficiency is influenced by both the nature of the anionic dyes and the pH of the initial dye solution. Electrostatic adsorption played a more important role in flocculation of dyes than bridging of the polymer. Moreover, the inorganic salt decreased the efficiency of color removal.