soheila izadyar; Roghayeh Hamzezadeh; Davood Efhamisisi
Abstract
The aim of this study was to investigate the effect of poplar wood saturation with nano-wollastonite and nano-wollastonite-styrene mixture on fire resistance and mechanical properties of polymer wood. Populus deltoids with 4% nano-wollastonite and 75% methanolic solution of styrene monomer was saturated ...
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The aim of this study was to investigate the effect of poplar wood saturation with nano-wollastonite and nano-wollastonite-styrene mixture on fire resistance and mechanical properties of polymer wood. Populus deltoids with 4% nano-wollastonite and 75% methanolic solution of styrene monomer was saturated by vacuum-pressure method. Four different wood treatments with nano-wollastonite, styrene, simultaneous nano-wollastonite and styrene (one-step) by 1:1 ratio and finally, the initial wood saturation by nano-wollastonite and then styrene (two-stage treatment) were investigated. In this study, the fire resistance and mechanical properties of the specimens were investigated. The results showed that the weight loss of wood against fire in two-stage treatment (NW+St) was 61.38% and in one-stage treatment (NW/St) was 69.68% better than control. NW/St treatment flame durability was approximately equal to NW treatment and improved by 30% compared to control. The reduction of carbonized area in two-stage (NW+St) and one-stage (NW/St) treatments was 28.53% and 29.06%, respectively, which showed a significant decrease. The results of mechanical tests showed that the NW/St treatment had the highest value due to the presence of condensing material in parallel to the NW/St treatment which showed an increase of 57.41% compared to the control sample. The modulus of elasticity and disruption of NW/St treatment increased by 26.77% and 35.71%, respectively. In addition, resistance to hardness of NW/St treatment increased by 10.07% compared to control. Overall, it can be concluded that mixing nano-wollastonite with styrene, while increasing the polymer wood fire resistance, also improved the mechanical properties of the polymer wood.
Management and Economics wood
Saeed Khojasteh Khosro; Masoud Taghipour Javy
Abstract
The main objective of the current study was the investigation of the effect of adding the wollastonite nanoparticles (casio3) to the water based acrylic coating onto the fire resistance capability and adhesion strength of coating. The nano wollastonites with the concentrations of 0.5, 1.50, and 2.5 wt% ...
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The main objective of the current study was the investigation of the effect of adding the wollastonite nanoparticles (casio3) to the water based acrylic coating onto the fire resistance capability and adhesion strength of coating. The nano wollastonites with the concentrations of 0.5, 1.50, and 2.5 wt% were dispersed into the coating. Ultrasonic device was used to stabilize the nanoparticles into the substrates. The coating process was carried out with and without application of the nanoparticles on the surfaces of spruce and sycamore samples and their properties comprising the fire resistance and the adhesion strength were investigated. The obtained results showed that adding of nano wollastonite to the acrylic coating with the waight percent of 2.5% (w/w) had the significance effect onto the resistance of the samples to fire. In particluar, these effects was observed in cas of the retard time of ignition of the spruce and sycamore samples with the improvement values of 258 and 184 % compared with the control samples, respectively. Furthermore, the investigation of adhesion properties of coatings to the sample surface indicated that the applied nano wollastonites improved these properties of coatings. In case of the adhesion properties, however, the highest value of this properties was observed in the highest content of wollastonite nanoparticles. It should be noted that the performance of nanocomposite coating containing of the 1.5 wt% of nano onto investigated properties was also acceptable.
Composite wood products
Hossein Rangavar; Seid asghar Alavi seresht
Abstract
This research was conducted to investigate the effect of nano-wollastonite and the use of polymers polyvinyl chloride and heavy polyethylene on the fire resistance of particleboard with three layers made of pepper stalk and industrial wood particles. Urea-formaldehyde adhesive with concentration of 12% ...
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This research was conducted to investigate the effect of nano-wollastonite and the use of polymers polyvinyl chloride and heavy polyethylene on the fire resistance of particleboard with three layers made of pepper stalk and industrial wood particles. Urea-formaldehyde adhesive with concentration of 12% containing nanowollastonite with mixing ratio of 10% (based on dry mass of wood material) was used. The board in three levels matched (mixture industrial wood with pepper stalk particles), in the form of three layers, include the core layer pepper stalk particles and the surface layer of industrial wood particles, the core layer industrial wood particles and the surface layer of pepper stalk particles and two levels of heavy polyethylene and polyvinyl chloride polymers and nano in the two levels (with nano and without nano) were considered variable factors. Test specimens for examination of characteristics of fire resistance boards were made to include ignition timing(s), fusion time(s), weight loss(%) and carbonized area(mm2) each in two times of 2 and 30 minutes in accordance with the ISO 11925 standard was prepared and evaluated. The results showed that the use of nano-wollastonite and polyvinyl chloride and heavy polyethylene polymer and the boards were improved fire resistance .In particular, heavy polyethylene polymer has a better effect on the fire resistance of the boards. Three layers boards with industrial wood particles on the surface had a long ignition and fusion time. Moreover, percentage of weight loss and carbonized area in a three layer boards with pepper stalks particles on the surface were low