Yashar Einollahi; Amir Hooman Hemmasi; Habibollah Khademi Eslam; Esmaeil Ghasemi; Mohammad Talaei poor
Abstract
Considering the increase of environmental pollutant resulted from agglomerating rubbish and wastes containing stable petroleum-based polymers, substitution of these polymers with bio-polymers and solving their problems and defects in the production process as well as the final products is an important ...
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Considering the increase of environmental pollutant resulted from agglomerating rubbish and wastes containing stable petroleum-based polymers, substitution of these polymers with bio-polymers and solving their problems and defects in the production process as well as the final products is an important topic. In this study, the possibility of the production of poly lactic acid (PLA)-rice husk composite with acceptable properties, and also the effect of using flame retardant mineral fillers of aluminum three hydrates (ATH) and magnesium di-hydroxide (MDH) on physical and thermal properties of the produced composite were investigated. Results indicated that the density of PLA-rice husk composite was higher than petroleum-based polymers composites (PP/HDPE-rice husk composites); and flame retardant mineral fillers addition led to an increase in the composite density. Also, flame retardant mineral fillers addition decreased the composite water absorption and thickness swelling, in a way that they were comparable with petroleum-based polymers composites. Results of thermal gravimetric analysis (TGA) showed that flame retardant mineral fillers addition also decreased the temperature of the composite weight loss curve peaks, and the weight loss rate toward temperature rising.
Composite wood products
Hamid Ibaghi esfahani; mehdi kalagar; hosien sepahri rad
Abstract
In this study, the tensile and dynamic-mechanical properties of composites made by poly-lactic acid polymer (PLA) and high density polyethylene (HDPE) as matrix and sawdust to reinforcement 30 % weight were investigated. Maleic anhydride bonded with polyethylene (MAPE) was used to increase coupling agent ...
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In this study, the tensile and dynamic-mechanical properties of composites made by poly-lactic acid polymer (PLA) and high density polyethylene (HDPE) as matrix and sawdust to reinforcement 30 % weight were investigated. Maleic anhydride bonded with polyethylene (MAPE) was used to increase coupling agent by 3%. The use of sawdust increased the stiffness of composites while the use of this material reduced the tensile strength of composites. The highest tensile properties (elastic modulus and tensile strength) were related to poly lactic acid /polyethylene / sawdust / coupling agent composites. The addition of natural fibers to both matrices (PLA and MAPE) increased the composite storage modulus compared to pure polymers, while the modulus of storage in pure polyethylene and its composite was higher. Simultaneous use of two polymers with an equal ratio (33.5% by weight) and composite sawdust have shown the stiffness between the composites made with single polymers. The use of natural fibers reduced the mobility of the molecular chain and transported the temperature of the composite to higher temperatures, which eventually moved the corresponding corners to the right and lower. However, in some cases, the transmission of pixels has not followed the normal process. The addition of the coupling agent (MAPE) makes bonding more common between two phases in all composites and ultimately increases stiffness.
Composite wood products
Mehdi Kalagar; behzad baziyar; Habibalah Khademislam; Esmaeil Ghasemi; Amir homan Hemmasi
Abstract
In this paper, poly lactic acid (PLA)/ wheat straw fibers manufactured by twin screw extruder and molding compression have been studied. Wheat straw fibers were treated with trietoxymethel silane for better compatibility between two phases. Physical properties, tensile properties of the composites were ...
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In this paper, poly lactic acid (PLA)/ wheat straw fibers manufactured by twin screw extruder and molding compression have been studied. Wheat straw fibers were treated with trietoxymethel silane for better compatibility between two phases. Physical properties, tensile properties of the composites were analysis. The effect of the wheat straw fibers on the thermal properties of PLA has also been investigated in DSC experiments. The effects of silane treatment on the wheat straw fibers have been analyzed by FTIR. Scanning electron microscopy from samples surface were used for better study of water absorption and thickness swelling. Composites wheat straw fiber were treated shows signification lower water absorption and thickness swelling than composites PLA/ untreated wheat straw fibers. The lower amount of water absorption and thickness swelling occurred in the pure PLA. The existence crack and break occurred in the surface of PLA/ untreated wheat straw fibers composites after immersion in the water indicating higher water absorption and thickness swelling were in these samples. Wheat straw fibers were treated with silane due to better wetting and better linkage in the interfacial surface with PLA matrix showed higher tensile properties then PLA/ untreated wheat straw fiber composites. Differential scanning calorimeter test showed that with addition wheat straw fibers were treated to pure PLA the increased glass transition temperatures. The nucleating effect of wheat straw fibers, special treatment with silane cause to increased in the crystallization temperature composites than pure PLA which a positive effect showed on the degree of crystallization.
