The interface interaction between water-soluble chitosan (DD = 50%) and peroxide bleached reed kraft pulp

Application of spherical polyelectrolyte brushes microparticle system in flocculation and retention

In this paper, a microparticle system consisting of cationic polyacrylamide (CPAM) and anionic spherical polyelectrolyte brushes (ASPB) is proposed to improve the retention of pulp suspension containing bleached reed kraft pulp and precipitated calcium carbonate (PCC). We first describe the preparation of ASPB. The ASPB, consisting of a carbon sphere (CS) core and a shell of sodium polystyrene sulfonate (PSSNa) brushes, was synthesized by surface-initiated polymerization. The structure and morphology of ASPB were characterized by Fourier-transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Then, flocculation and retention of pulp suspension by a CPAM/ASPB dual-component system were examined. Our results indicate that more highly effective flocculation and higher retention efficiency could be achieved simultaneously by a CPAM/ASPB dual-component system when compared to the conventional microparticle system. Bridging flocculation and electrostatic attraction might be the main flocculation mechanism for CPAM/ASPB systems.

One-pot synthesis of cellulose-based nonwoven web incorporated with chitosan for hemostat applications

Water-soluble chitosan and wood pulp fiber–based nonwovens were produced using wet-laying technology, and their properties were investigated for the potential application for severe hemorrhage. The pores of the wood pulp nonwovens were completely covered as the concentration of chitosan was increased. A phosphate buffer solution uptake of 997% was attained in the nonwoven loaded with chitosan concentration of 1.5 w/v%. The deposition of blood cells was found to increase with an increase in the water-soluble chitosan concentration. The blood-clotting time was found to be 170 s, making the developed nonwoven to promote blood-clotting mechanism by creating mechanical barrier to reduce the blood loss.

Characterization of Epoxy Composites Reinforced with Wax Encapsulated Microcrystalline Cellulose

The effect of paraffin wax encapsulated microcrystalline cellulose (EMC) particles on the mechanical and physical properties of EMC/epoxy composites were investigated. It was demonstrated that the compatibility between cellulose and epoxy resin could be maintained due to partial encapsulation resulting in an improvement in epoxy composite mechanical properties. This work was unique because it was possible to improve the physical and mechanical properties of the EMC/epoxy composites while encapsulating the microcrystalline cellulose (MCC) for a more homogeneous dispersion. The addition of EMC could increase the stiffness of epoxy composites, especially when the composites were wet. The 1% EMC loading with a 1:2 ratio of wax:MCC demonstrated the best reinforcement for both dry and wet properties. The decomposition temperature of epoxy was preserved up to a 5% EMC loading and for different wax:MCC ratios. An increase in wax encapsulated cellulose loading did increase water absorption but overall this absorption was still low (<1%) for all composites.