Investigating the effect of methylation treatment on the kraft lignin optical behavior through simulation of lignin-containing papers

In this study, changes in optical behavior of Poplar Kraft lignin before and after methylation by using dimethyl sulphate, was monitored by measuring optical indices ( brightness,light absorbtion coefficient, light scattering coefficient,light absorbtion coefficient to light scattering coefficient ratio and Post-Color numbers) of impregnated papers following accelerated photo aging. The structural changes in lignin caused by methylation reaction, were verified by using fourier transform infar red( FT-IR) spectroscopy. The results showed that, by methylation of lignin, it was observed that, in methylated lignin-containing papers, the extent and stability of brightness is more and post- color number is less compared to control samples. In methylated samples, even the strange phenomenon of photo bleaching was observed. Therefore, it was found that, methylation of lignin can prevent the formation of quinone groups and increases the stability of the optical indices in the photo aging conditions.Keywords: Kraft lignin, methylation treatment, accelerated photo- aging, optical indices,lignin-containing papers

Investigation on the effect of acetylation and reduction treatments on the chromophore groups of isolated lignin from unbleached hardwoods chemimecanical pulp using FT-IR spectroscopy

This study lignin from unbleached hardwoods chemimechanical pulp was extracted and the chromophor functional groups of the lignin were studied. Acetylation and reduction treatments were perfomed and samples were analyzed by FT-IR spectroscopy. A mild acidic dioxin extraction method was employed to isolate lignin. For the acetylation and reduction treatments of lignin acetic acid and sodium borohydride were used respectively. The results of untreated and treated (acetylated and reduced) lignin spectra showed that, the major of lignin chromophor groups such as hydroxyl and carbonyl groups have been reduced or eliminated by these treatments. In the acetylated lignin, the absorption band of hydroxyl groups has been weakened and in the 1743.16 Cm-1 region, acetoxy compounds band has appeared and also a cluster absorption band was observed in the 1228.76 Cm-1 region. In the reduced lignin, most of the absorption bands of the carbonyl groups have been weakened or eliminated, especially in the 1705.56 and 1629.54 Cm-1 region

Investigation on Physical and Mechanical Properties of Nanocomposites Made From Flour Of Pistachio Shell/ Corn Starch/ Nanoclay

In this study, effects of the flour of cellulosic shell of Pistachio and nanoclay loading on the physical and mechanical properties of wood plastic composite were investigated. Hence, flour of cellulosic shell of Pistachio, in levels of 30, 40 and 50 and Nano clay of cloisite 15A in three levels (0, 3 and 5%) was mixed with Corn starch polymer. Samples were made with a laboratory twin-screw extruder and then injection molding. The heating temperature profile and rotational speed of the screws were set at 180–170–160–160 oC and 60 rpm, respectively. Mechanical properties including tensile and flexural properties as well as notched impact strength and physical properties including water absorption and thickness swelling were measured. The results showed that flexural and tensile strength, water absorption of the samples increased as the flour content increased from 30 to 50% (w/w), but tensile modulus, notched impact resistance and thickness swelling decreased. Furthermore, tensile modulus increased as the Nannoclay content increased from 0 to 5% (w/w). Besides, Flexural and tensile strength, Flexural modulus, notched impact resistance increased as Nannoclay content increased from 0 to 3% (w/w). beyond this limit (to 5% (w/w)), they decreased.Water absorption and thickness swelling of the samples decreased as the Nannoclay content increased from 0 to 5% (w/w)

Investigation on TCF Bleaching of Tobacco stalk ( Nicotiana tabacum L.'Coker 347') Soda Pulp

In this study the effect of different values of peroxide in three levels 3%, 4%, 5% and sodium hydroxide in two levels 2%, 3%, on bleaching of tobacco stalks ( Nicotiana tabacum L. 'PVH 19') soda pulp was investigated. Tobacco stalks were soda pulped using 22% alkali in 170°C for 100 minutes. Produced pulp had 37.1 % yield and kappa number 62. Bleaching process included two stages: chelating and alkali peroxide bleaching. Results indicated that brightness increased and kappa number decreased by increasing sodium hydroxide and peroxide Hydrogen level.The data related to 3% caustic soda and 5% peroxide treatment without chelating stage, indicated that initial chelating stage significantly affected on the brightness, kappa number and yield of the bleached pulp, and this treatment had the lowest brightness and the highest kappa number and yield among all treatments. Finally, 3% caustic soda-5% peroxide treatment with initial chelating stage had the highest brightness (44.50%) and the lowest yield (83.20%), was selected as the best treatment

Identify the Chemical Composition of Tobacco Stem Wood Extractives (Nicotiana tabacum L. 'Coker 347') by Gas Chromatography- Mass Spectrometry

Tobacco (Nicotianan tabacum) and an old industrial plant in the north, Iran to supply tobacco leaf to produce significant amounts of stem tobacco cultivation and the annual production is in the north of the country. In this research stems of tobacco variety Coker 347 randomly Gilan district, city of Astara was prepared according to the TAPPI standard test, wood flour were prepared and extractives were determined. The results showed that the mean shoot extractive tobacco varieties Coker 347 (10.41 percent). The extractive solvent toluene - ethanol volume ratio (2 : 1) of milled wood was extracted. Extractive made into a glass vial and transferred to the BSTFA reagent was added. Samples for one hour at room temperature and 70 ° C water bath and then by (GC / MS) were analyzed. Atotal of 11 chemical compounds in tobacco stem wood extractives variety Coker 347 were identified with different percentages of tobacco stem wood Coker 347 varieties exist. These compounds include, P- Prydyn , 1 – tri methyl Saylyl , 1,2 - benzene di- carboxyl acid , alpha - D - Golokopyranoz , 11, 8 – di methyl - 13 - (4 - aksu -1 - methyl ) , tri Floyver methyl isopropyl sulfide are the highest values

Anatomical, morphological and chemical properties of Tobacco stalk (Nicotiana tabacum L.)

Tobacco (Nicotiana tabacum) is one of the non-wood species and its stalks are the main crop after harvesting  which can be used in composite board and paper industry. For better use of this non-wood fibrous raw material, the evaluation of anatomical, morphological and chemical components are necessary. Tobacco stalks "Coker"cultivar 347 which is widely planted in Gilan province of Iran were randomly sampled. Anatomical properties (cross, tangential and radial sections) and morphological properties (fiber length, fiber diameter, and cell wall thickness) were measured and the indices and ratio of the fibers including: slenderness index, runkel index, flexibility ratio in three heights of stem (5%, 50% and 75%) were calculated. The Chemical components including: Cellulose, lignin, ash, alpha cellulose and hemicellulose of stem with bark and without bark were recorded according to related standards and the results were ststistically analyzed. Results showed that the chemical components of the tobacco stalk were desirable but the index of L/D of fibers were lower than many non-woods and hardwoods. Therefore, it is assumed that the paper produced from tobacco stalks do have suitable tear strength. The runkel index (2 cell wall thickness / fiber diameter) is close to hardwoods and many non-woods, Therefore, it is presumed that paper have appropriate tensile, burst and folding strength. It is predicted that tobacco stalks combined with softwoods with long fibers can produce good quality paper