Composites based on jute fabrics and polypropylene was fabricated by heat-press molding technique. The mechanical properties of the composites such as tensile strength, tensile modulus, bending strength, bending modul...Composites based on jute fabrics and polypropylene was fabricated by heat-press molding technique. The mechanical properties of the composites such as tensile strength, tensile modulus, bending strength, bending modulus and impact strength were measured in dependence of fiber contents. In order to improve fiber-matrix interaction, jute fabrics were treated with aqueous solutions of K2Cr2O7 (0.005-0.05% w/v). Composite prepared with 0.02% K2Cr2O7 treated jute fabrics showed the highest values of the mechanical properties. Thermogravimetric (TG/DTG) data of PP, jute fabrics and composites showed that thermal degradation temperatures of composites shifted to higher temperature regions compared to PP or jute fabrics. Treatment of jute fabrics improved the thermal stability of the composite considerably. Scanning electron microscopic images of tensile fractured sides of untreated and treated composites illustrated that better fiber-matrix interfacial interaction occurred in treated composite. The relative tendency of water absorption of both untreated and treated composites was also explored.展开更多
Gelatin films were prepared by casting. Tensile strength (TS) and elongation at break (Eb) of the gelatin films were found to be 46 MPa and 3.5%, respectively. Effect of gamma radiation (Co-60) on the thermo-mechanica...Gelatin films were prepared by casting. Tensile strength (TS) and elongation at break (Eb) of the gelatin films were found to be 46 MPa and 3.5%, respectively. Effect of gamma radiation (Co-60) on the thermo-mechanical properties of the gelatin films was studied. 2-hydroxyethyl methacrylate (HEMA) was added to the gelatin during casting varying (10% - 30% by weight) and found to increase the TS significantly. Then the films were irradiated and found further increase of TS. Thermo-mechanical properties of HEMA blended gelatin films were compared with those of the pure gelatin films. The coefficient of thermal expansion of the gelatin/HEMA films were also measured using thermo mechanical analyzer and found opposite trend with comparison of glass point.展开更多
Twill woven Carbon-Kevlar (CK) fabric was reinforced in epoxy matrix by conventional hand lay-up process. The fabric weight fraction in the composites was kept around 58% and stacking sequence was varied from single t...Twill woven Carbon-Kevlar (CK) fabric was reinforced in epoxy matrix by conventional hand lay-up process. The fabric weight fraction in the composites was kept around 58% and stacking sequence was varied from single to five plies. Tensile test was performed and the fracture surface after tensile test was evaluated by scanning electron microscope (SEM). The test result revealed that the tensile properties are strongly dependent on the number of plies. Three point flexural test of the composite was also carried and an increasing trend was observed. Maximum impact energy was recorded for CK3 sample by 202.7 KJ/m2. Thermal stability of the composite was studied via the thermo gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR) result show interaction between fiber and matrix material. Finally, CK fabric reinforced epoxy-based composites showed balanced and tailor-able mechanical properties by varying the number of plies, suitable for desired applications in many areas including building, construction, marine, automotive etc.展开更多
文摘Composites based on jute fabrics and polypropylene was fabricated by heat-press molding technique. The mechanical properties of the composites such as tensile strength, tensile modulus, bending strength, bending modulus and impact strength were measured in dependence of fiber contents. In order to improve fiber-matrix interaction, jute fabrics were treated with aqueous solutions of K2Cr2O7 (0.005-0.05% w/v). Composite prepared with 0.02% K2Cr2O7 treated jute fabrics showed the highest values of the mechanical properties. Thermogravimetric (TG/DTG) data of PP, jute fabrics and composites showed that thermal degradation temperatures of composites shifted to higher temperature regions compared to PP or jute fabrics. Treatment of jute fabrics improved the thermal stability of the composite considerably. Scanning electron microscopic images of tensile fractured sides of untreated and treated composites illustrated that better fiber-matrix interfacial interaction occurred in treated composite. The relative tendency of water absorption of both untreated and treated composites was also explored.
文摘Gelatin films were prepared by casting. Tensile strength (TS) and elongation at break (Eb) of the gelatin films were found to be 46 MPa and 3.5%, respectively. Effect of gamma radiation (Co-60) on the thermo-mechanical properties of the gelatin films was studied. 2-hydroxyethyl methacrylate (HEMA) was added to the gelatin during casting varying (10% - 30% by weight) and found to increase the TS significantly. Then the films were irradiated and found further increase of TS. Thermo-mechanical properties of HEMA blended gelatin films were compared with those of the pure gelatin films. The coefficient of thermal expansion of the gelatin/HEMA films were also measured using thermo mechanical analyzer and found opposite trend with comparison of glass point.
文摘Twill woven Carbon-Kevlar (CK) fabric was reinforced in epoxy matrix by conventional hand lay-up process. The fabric weight fraction in the composites was kept around 58% and stacking sequence was varied from single to five plies. Tensile test was performed and the fracture surface after tensile test was evaluated by scanning electron microscope (SEM). The test result revealed that the tensile properties are strongly dependent on the number of plies. Three point flexural test of the composite was also carried and an increasing trend was observed. Maximum impact energy was recorded for CK3 sample by 202.7 KJ/m2. Thermal stability of the composite was studied via the thermo gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR) result show interaction between fiber and matrix material. Finally, CK fabric reinforced epoxy-based composites showed balanced and tailor-able mechanical properties by varying the number of plies, suitable for desired applications in many areas including building, construction, marine, automotive etc.
