Mania Jadidi; Noraldin Neghad; Majid Zabihzadeh
Abstract
This research was conducted to find a procedure to increase the optical and strength properties of papers made from oxidized waste newspaper fibers. Samples of waste newspapers were randomly selected and deinked, then one part of deinked pulp was refined. Both refined and unrefined recycled pulp ...
Read More
This research was conducted to find a procedure to increase the optical and strength properties of papers made from oxidized waste newspaper fibers. Samples of waste newspapers were randomly selected and deinked, then one part of deinked pulp was refined. Both refined and unrefined recycled pulp were divided into two groups. In each case, a group of pulps was used to make standard hand sheets (control samples) without hydrogen peroxide treatment and only adding 2% cationic starch. Second group was subjected to different percentages of hydrogen peroxide (2%, 3% & 4%) in alkaline conditions, then 2% cationic starch was added to oxidized fibers prior to hand sheeting preparation and then standard hand sheets were made. Opticaland strength properties of all hand sheets were determined according to TAPPI standards. Also FTIR spectra was taken to specify the effect of oxidation on surfaces of pulp fibers. Results showed that treatment with oxidizing agent increased the strength indices of papers. This increase was more evident when 3% hydrogen peroxide was applied. The strengths of the control samples were the lowest. Moreover, refining imposed the positive effect on strength properties. Results of optical properties measurements indicated that as the extent of treatment for both refined and unrefined pulps increases, the brightness increased, and both the yellowness and opacity decreased. The highest brightness was reached when 3% peroxide was used. Also refining results in increased in brightness and yellowness but decreas opacity. FTIR spectra showed that samples of oxidized pulp had the greatest absorption at wave number of 1650 which pertains to carboxyl group.
Noraldin Nazarnezhad
Abstract
This research was conducted to investigate the posibility of producing particleboards using surface activation method of P. deltoides particles and then using cross-linking agents to bond wood particles. At first, nitric acid as an oxidative agent at different proportion including 0, ...
Read More
This research was conducted to investigate the posibility of producing particleboards using surface activation method of P. deltoides particles and then using cross-linking agents to bond wood particles. At first, nitric acid as an oxidative agent at different proportion including 0, 3, 4.5 & 6 percent (based on OD weight of wood) and two assembly times of 0 and 1 hour was used. Black liquor at two amounts of 5 and 7 percent was used as cross-linking agent. The results indicates that using 6% nitric acid and 7% liquor had the best performance and that, the assembly time of 1 hour had negative effect on all properties. The ATR spectrum of treated samples showed the increase in the absorbtion rate at 1740 cm-1 related to COOH group as compared with control samples. In addition, the spectrum indicated that increasing oxidation increase absorbtion rate of COOH group.
Composite wood products
Hassan Zyaei; Habib alah Khademi eslam; Behzad Bazyar; Noraldin Nazarneghad
Abstract
The aim of this study was to determine effect of coupling agent contents on the thermal properties and nanoclay dispersion of reed flour /polypropylene /nanoclay composites. For this purpose we considered wood flour 40% fixed maleic anhydride in two levels (5% and 10%) and nanoclay (Cloisite 10A) in ...
Read More
The aim of this study was to determine effect of coupling agent contents on the thermal properties and nanoclay dispersion of reed flour /polypropylene /nanoclay composites. For this purpose we considered wood flour 40% fixed maleic anhydride in two levels (5% and 10%) and nanoclay (Cloisite 10A) in three levels (0, 1 and 3%). The materials were mixed in an internal mixer with 175 oC, 60 rmp for 10 minutes and then the specimens were fabricated by injection molding method. The clay structure and dispersion processes have been studied by X-ray diffraction. Thermal characterizations of the nanocomposites were carried out using Differential Scanning Calorimeter (DSC). The results revealed that Enthalpy, Crystallinity and Crystalline temperature of composites were increased by adding up of coupling agent and nanoclay (in some levels) contents. The XRD patterns show the exfoliation structure of nanoclay that indicated on a good dispersion of clay in polymer matrix, which turn in a reason for increasing thermal properties.
Pulp and paper
Noraldin Nazarnezhad; Mohammad taghi Asdolahzadeh
Abstract
This study was investigated the effect of Trametes versicolor on chemimechanical pulp (CMP) delignification. CMP were obtained from Mazanderan wood and paper industries. Circle mats were made from CMP (diameter, 7cm; thickness, 1mm) and fortified with 1g/Lit yeast juice. After sterilized, pulp mats were ...
Read More
This study was investigated the effect of Trametes versicolor on chemimechanical pulp (CMP) delignification. CMP were obtained from Mazanderan wood and paper industries. Circle mats were made from CMP (diameter, 7cm; thickness, 1mm) and fortified with 1g/Lit yeast juice. After sterilized, pulp mats were incubated with tow disks punched from mycelium. The duration of incubate were 5, 10, 15 & 20 days as well as temperature and moisture 25oC and 40%, respectively. Standard hand sheets were made from biodelignification pulp, and was measured mechanical and optical properties. The portion of biodelignification pulp was alkaline extracted under condition of pulp consistency, 10%; temperature, 70oC; time, 80min and 2% sodium hydroxide, and then bleached under conditions of pulp consistency, 10%; temperature, 50oC; time, 60min and 4% hydrogen peroxide. Finally, mechanical and optical properties of standard hand sheet were measured. Results showed optimum time was 10 days that decreased 5.9% lignin. Mechanical properties of treated samples were lower than control samples, but statically were not significant. Optical properties of treated samples were lower than control samples but alkaline extraction and then bleaching with sodium peroxide was increase it.
