Alkaline peroxide treatment of ECF bleached softwood kraft pulps. Part 1. Characterizing the effect of alkaline peroxide treatment on carboxyl groups of fibers
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Zheng Dang
Abstract
The influence of alkaline peroxide treatment has been characterized on elementally chlorine-free (ECF) bleached softwood (SW) kraft pulp. The results indicate that fiber charge increased with an increase in peroxide charge: a maximum fiber charge increment of 16.6% was obtained with 8.0% more peroxide charge on oven-dried (o.d.) pulp at 60.0°C. Two primary bleaching temperatures of 60.0°C and 90.0°C were investigated during peroxide treatment. Copper number decreased for peroxide charges of 0.5% and 1.0% at 60.0°C and 90.0°C, respectively, then increased with increasing peroxide charge. Both fiber charge and copper number approached constant values when 4.0% or higher peroxide charge was applied. Peroxide treatment on a bleached kraft pulp at 90.0°C resulted in lower fiber charge and lower intrinsic viscosity compared to treatment at 60.0°C. Sodium borohydride (NaBH4) pretreatment was able to protect the fibers from being degraded during peroxide bleaching. Fiber charge and copper number were compared after peroxide treatment of ECF bleached kraft pulp to NaBH4-reduced ECF bleached kraft pulp. The results indicate that the carbonyl group content of fibers is favorable for improving fiber charge after peroxide treatment.
©2007 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Meetings
- Micromechanical modeling of solid-type and plate-type deformation patterns within softwood materials. A review and an improved approach
- Failure mechanisms in wood-based materials: A review of discrete, continuum, and hybrid finite-element representations
- Morphological lattice models for the simulation of softwood failure and fracture
- Experimental and numerical investigation of wood fracture mechanisms at different humidity levels
- Material point method simulations of transverse fracture in wood with realistic morphologies
- Simulation of cracks in wood using a coupled material model for interface elements
- Preliminary tests to evaluate the mechanical properties of young trees with small diameter
- Characterization and strength modeling of parallel-strand lumber
- Dynamic behaviour of cork and cork-filled aluminium tubes: Numerical simulation and innovative applications
- A numerical study of the transverse modulus of wood as a function of grain orientation and properties
- Effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species
- Experimental device for the accurate determination of wood-water relations on micro-samples
- Evaluating the suitability of hybrid poplar clones for the manufacture of oriented strand boards
- Finely milled kenaf core as a natural plywood binder
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps. Part 1. Characterizing the effect of alkaline peroxide treatment on carboxyl groups of fibers
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps: Part 2. Effect of increased fiber charge on refining, wet-end application, and hornification
- Molar mass determination of lignins by size-exclusion chromatography: towards standardisation of the method
Articles in the same Issue
- Meetings
- Micromechanical modeling of solid-type and plate-type deformation patterns within softwood materials. A review and an improved approach
- Failure mechanisms in wood-based materials: A review of discrete, continuum, and hybrid finite-element representations
- Morphological lattice models for the simulation of softwood failure and fracture
- Experimental and numerical investigation of wood fracture mechanisms at different humidity levels
- Material point method simulations of transverse fracture in wood with realistic morphologies
- Simulation of cracks in wood using a coupled material model for interface elements
- Preliminary tests to evaluate the mechanical properties of young trees with small diameter
- Characterization and strength modeling of parallel-strand lumber
- Dynamic behaviour of cork and cork-filled aluminium tubes: Numerical simulation and innovative applications
- A numerical study of the transverse modulus of wood as a function of grain orientation and properties
- Effects of ring characteristics on the compressive strength and dynamic modulus of elasticity of seven softwood species
- Experimental device for the accurate determination of wood-water relations on micro-samples
- Evaluating the suitability of hybrid poplar clones for the manufacture of oriented strand boards
- Finely milled kenaf core as a natural plywood binder
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps. Part 1. Characterizing the effect of alkaline peroxide treatment on carboxyl groups of fibers
- Alkaline peroxide treatment of ECF bleached softwood kraft pulps: Part 2. Effect of increased fiber charge on refining, wet-end application, and hornification
- Molar mass determination of lignins by size-exclusion chromatography: towards standardisation of the method
