Studing the effect of reducing agents (sodium borhydrade and sodium dithionite) on chemical structures of poplar kraft and bagasse soda alkali lignin by FT-IR spectroscopy

In this study, the chemical changes of functional groups (C=O) and double bond (C=C), induced in the structures of poplar kraft lignin and bagasse soda lignin were investigated. The reducing effect of sodium borohydride and sodium hydrosulfite, followed by the UV irradiation on these two compounds were determined using FT-IR spectroscopy. Results showed that, reduction of the lignin by reducing chemical imparted stability in lignin structure against UV light. The FT-IR spectroscopy showed that, the major light stabilizing phenomenon that is responsible for this stability is the conversion of carbonyl groups (C=O) alcohol group (C-OH) and double bonds (C=C) to single bonds (C-C). Between the two reducing compound, sodium borohydride showed better performance than sodium hydrosulfite

The Study of Fiber Fines and Its Effects On Optical and Physical Propertie of Newsprint Paper from CMP Pulp

The present study deals with effects of CMP  fines on optical and physical properties of newsprint papers, for which, different batches for CMP fines (0%, 10%. 20%. 30%) of totally 80% pulp  is taken, Where the remaining 20% of imported long fiber pulp was taken as fixed amount . The study focused on surving the effects of CMP fines on optical and physical properties of newsprint paper ,after mixing the pulps and making the handsheets . Generally, the results show the increase in CMP fine amount lead to increase ,Air Resistance and Opacity and decrease Caliper and Roughness, Also that changes in CMP fines has no effect on Brightness

Studying on the Soda and Dioxane Lignin of Bagasse using Derivatization Followed by Reductive Cleavage (DFRC)

In this study, the structure of Soda (soluble fraction in ethanol) and Dioxane lignins of bagasse were studied by using derivatization followed by reductive cleavage (DFRC) method and some techniques including gel permeation chromatography, gas chromatography-mass spectrometry and 13C-nuclear magnetic resonance spectroscopy and the results were compared. These comparative results show that the main monomeric compounds are obtained from the cleavage of β-O-4 bonds of lignins. The components obtained from Dioxane lignin and Soda lignin are guaiacyl, syringyl and p-hydroxyphenyl structures with different proportions. However, some differences have been observed in both lignins, including a variety of structural units in Dioxane lignin is greater than Soda lignin. In other words, soda lignin degradation and the structural components has become closer together and are more uniform structures. The average molecular weight of Dioxane lignin, is greater than Soda lignin, which is due to Soda lignin wide chemical degradation during industrial pulping processes and therefore it has less dense structure. These observations indicate that a mild method for lignin separation from a lignocellulosic material caused less damage and changes in lignin structure. Therefore, in structural studies, Dioxane lignin can actually be used as an appropriate representative of the lignin

STUDY ON THE POSSIBILITY OF MANUFACTURING PARTICLEBOARD WITH PAPER SLUDGE AND WOOD CHIPS

Beneficial utilization of large quantity of paper sludge from Mazandaran Wood & Paper Industry in particleboard manufacturing has been studied. Single-layer and three-layer particleboard (paper sludge as a surface layer) were produced. Urea-formaldehyde resin at two levels of 10 and 12 percent and paper sludge content at 4 levels, 0, 15, 30 and 45 percent were studied. Other factors such as press temperature (160oC), press time (6minutes), mat moisture (12%), board density (0.75g/cm3) and etc were constant factors. Mechanical and physical properties including bending strength, shear strength, thickness swelling and water absorption after 2 and 24 hours immersion were evaluated. The results indicated that application of paper sludge reduced mechanical properties and improved thickness swelling .The particleboard produced with 15%paper sludge had the least water absorption, but by using more paper sludge, water absorption increased. Single-layer particleboard had higher bending strength. However, there was no significant different in shear strength between single and three layer particleboard. Three-layer particleboard showed lower thickness swelling

The Investigation of Acetylation and Anti-Oxidant Effect on Weathering of wood Plastic Composites By Means of FTIR and Color Metry (Color measurement)

In this study capability of acetylated poplar flour in manufacture of high density poly ethylene composite which expose to accelerated weathering, was investigated. The acetylation degrees at medium and zero (control) levels, use of anti- oxidant and duration of weathering were considered as variables and their effects on discoloration and photodegradation of WPC were investigated. To determine treatments influence on changes and color fade resulting from weathering, samples were tested after o, 250, 2000 hours of weathering. The results indicated that application of acetylated wood flour in WPC can reduce about 25% of weathering discoloration in short time and about 17% in long time. Also it shows that as exposed time of weathering increase Anti oxidant loss its effect. Although in short time it can reduce 12% of weathering color changes. FTIR results show that after 2000 h of weathering all peaks samples had same decrease which mean none of the treatments were useful. But Anti oxidant can reduce depth of weathering