Extraction and characterization of novel lignocellulosic fibers from Thespesia lampas plant
- Reddy, K. Obi, Ashok, B., Reddy, K. Raja Narender, Feng, Y. E., Zhang, Jun, Rajulu, A. Varada
- Authors: Reddy, K. Obi , Ashok, B. , Reddy, K. Raja Narender , Feng, Y. E. , Zhang, Jun , Rajulu, A. Varada
- Date: 2014
- Subjects: Chemical composition , Crystallinity , Tensile properties , Thermal stability , Thespesia lampas , Lignocellulosic fibers
- Type: Article
- Identifier: uj:4818 , ISSN 1563-5341 , http://hdl.handle.net/10210/12259
- Description: In this work, the lignocellulosic fibers from the plant Thespesia lampas were extracted and investigated in detail. The prime objective of this work was to study the effect of alkali treatment on the chemical composition, tensile properties, morphological and structural changes, and thermal degradation of Thespesia lampas fibers. Chemical analysis, FT-IR, and 13C CP-MAS NMR spectroscopic studies indicated lowering of amorphous hemicellulose content on alkali treatment. Wide-angle X-ray diffraction studies indicated increase in crystallinity of the fibers on alkali treatment. The tensile strength and modulus of the fibers and thermal stability increased on alkali treatment. Scanning electron micrographs revealed roughening of the surface of the fibers due to the removal of the hemicellulose layer on alkali treatment. Tensile properties of Thespesia fibers were compared to those of other important natural fibers, and it was indicated as an alternative suitable source for composite construction.
- Full Text:
- Authors: Reddy, K. Obi , Ashok, B. , Reddy, K. Raja Narender , Feng, Y. E. , Zhang, Jun , Rajulu, A. Varada
- Date: 2014
- Subjects: Chemical composition , Crystallinity , Tensile properties , Thermal stability , Thespesia lampas , Lignocellulosic fibers
- Type: Article
- Identifier: uj:4818 , ISSN 1563-5341 , http://hdl.handle.net/10210/12259
- Description: In this work, the lignocellulosic fibers from the plant Thespesia lampas were extracted and investigated in detail. The prime objective of this work was to study the effect of alkali treatment on the chemical composition, tensile properties, morphological and structural changes, and thermal degradation of Thespesia lampas fibers. Chemical analysis, FT-IR, and 13C CP-MAS NMR spectroscopic studies indicated lowering of amorphous hemicellulose content on alkali treatment. Wide-angle X-ray diffraction studies indicated increase in crystallinity of the fibers on alkali treatment. The tensile strength and modulus of the fibers and thermal stability increased on alkali treatment. Scanning electron micrographs revealed roughening of the surface of the fibers due to the removal of the hemicellulose layer on alkali treatment. Tensile properties of Thespesia fibers were compared to those of other important natural fibers, and it was indicated as an alternative suitable source for composite construction.
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Microstructure and mechanical properties of ultra-fine grained copper processed by equal channel angular pressing technique
- Sanusi, Kazeem O., Afolabi, Ayo S., Muzenda, Edison
- Authors: Sanusi, Kazeem O. , Afolabi, Ayo S. , Muzenda, Edison
- Date: 2014
- Subjects: Tensile properties , Equal channel angular pressing technique , Grain refinement , Ultra-fine grained copper
- Type: Article
- Identifier: uj:5005 , ISSN 2078-0966 , http://hdl.handle.net/10210/13145
- Description: The equal channel angular pressing (ECAP) technique is now recognised for achieving very significant grain refinement of ultra-fine grained materials which, at present produce unique mechanical properties. This study reports the results of the tensile tests and the microstructural analysis carried out on the specimens of ultra-fine grained (UFG) copper processed by ECAP technique at room temperature using a die with a 126o between the die channels. The copper samples used in this work were subjected to six and twelve passes during the ECAP processing. Tensile tests were conducted for samples cut out in two different directions; in the parallel and perpendicular direction at room temperature to evaluate the mechanical properties after the ECAP at these two directions. The microstructural characterization was carried out using optical electron microscope (OEM) and scanning electronic microscope (SEM). The results show ECAP technique introducing significant grain refinement and produced ultrafine grains in copper and there is a potential for achieving high ductility in the copper alloy after processing. The tested sample is characterized by significant differences of strength properties depending on the direction.
- Full Text:
- Authors: Sanusi, Kazeem O. , Afolabi, Ayo S. , Muzenda, Edison
- Date: 2014
- Subjects: Tensile properties , Equal channel angular pressing technique , Grain refinement , Ultra-fine grained copper
- Type: Article
- Identifier: uj:5005 , ISSN 2078-0966 , http://hdl.handle.net/10210/13145
- Description: The equal channel angular pressing (ECAP) technique is now recognised for achieving very significant grain refinement of ultra-fine grained materials which, at present produce unique mechanical properties. This study reports the results of the tensile tests and the microstructural analysis carried out on the specimens of ultra-fine grained (UFG) copper processed by ECAP technique at room temperature using a die with a 126o between the die channels. The copper samples used in this work were subjected to six and twelve passes during the ECAP processing. Tensile tests were conducted for samples cut out in two different directions; in the parallel and perpendicular direction at room temperature to evaluate the mechanical properties after the ECAP at these two directions. The microstructural characterization was carried out using optical electron microscope (OEM) and scanning electronic microscope (SEM). The results show ECAP technique introducing significant grain refinement and produced ultrafine grains in copper and there is a potential for achieving high ductility in the copper alloy after processing. The tested sample is characterized by significant differences of strength properties depending on the direction.
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Preparation and characterization of polypropylene carbonate bio-filler (eggshell powder) composite films
- Feng, Ye, Ashok, B., Madhukar, K., Zhang, Jinming, Zhang, Jun, Reddy, K. Obi, Rajulu, A. Varada
- Authors: Feng, Ye , Ashok, B. , Madhukar, K. , Zhang, Jinming , Zhang, Jun , Reddy, K. Obi , Rajulu, A. Varada
- Date: 2014
- Subjects: Biocomposites , Eggshell powder , Fractographs , Polypropylene carbonate , Tensile properties , Thermal degradation
- Type: Article
- Identifier: uj:4815 , ISSN 1563-5341 , http://hdl.handle.net/10210/12256
- Description: In recent years, biodegradable polymer composites have attracted considerable attention due to inadequate and depleting petroleum resources and to replace nonbiodegradable synthetic polymers posing environment problems. In the present work, biodegradable composites based on polypropylene carbonate (PPC)=eggshell powder (ESP) were prepared by the solution-casting method using chloroform as the solvent. Polypropylene carbonate was loaded with 1 to 5 wt% of eggshell powder (particle size<40 mm). Characterization of the composites was accomplished by Fourier transform-infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) analysis, and morphological studies were carried out by optical microscopy (OM) and scanning electronic microcopy (SEM). The tensile properties of the composite films were found to be higher than those of neat PPC matrix and increased with ESP content up to 4 wt.% and then decreased. This work offers an easy path to manufacture ecofriendly PPC=eggshell powder com- posite films with improved properties, and reducing, in some cases, the demand for petroleum-based plastics such as polyolefins.
- Full Text:
- Authors: Feng, Ye , Ashok, B. , Madhukar, K. , Zhang, Jinming , Zhang, Jun , Reddy, K. Obi , Rajulu, A. Varada
- Date: 2014
- Subjects: Biocomposites , Eggshell powder , Fractographs , Polypropylene carbonate , Tensile properties , Thermal degradation
- Type: Article
- Identifier: uj:4815 , ISSN 1563-5341 , http://hdl.handle.net/10210/12256
- Description: In recent years, biodegradable polymer composites have attracted considerable attention due to inadequate and depleting petroleum resources and to replace nonbiodegradable synthetic polymers posing environment problems. In the present work, biodegradable composites based on polypropylene carbonate (PPC)=eggshell powder (ESP) were prepared by the solution-casting method using chloroform as the solvent. Polypropylene carbonate was loaded with 1 to 5 wt% of eggshell powder (particle size<40 mm). Characterization of the composites was accomplished by Fourier transform-infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) analysis, and morphological studies were carried out by optical microscopy (OM) and scanning electronic microcopy (SEM). The tensile properties of the composite films were found to be higher than those of neat PPC matrix and increased with ESP content up to 4 wt.% and then decreased. This work offers an easy path to manufacture ecofriendly PPC=eggshell powder com- posite films with improved properties, and reducing, in some cases, the demand for petroleum-based plastics such as polyolefins.
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Tensile and thermal properties of poly(lactic acid)/eggshell powder composite films
- Ashok, B., Naresh, S., Reddy, K. Obi, Madhukar, K., Cai, J., Zhang, L., Rajulu, A. Varada
- Authors: Ashok, B. , Naresh, S. , Reddy, K. Obi , Madhukar, K. , Cai, J. , Zhang, L. , Rajulu, A. Varada
- Date: 2014
- Subjects: Eggshell powder , Poly(lactic acid) , Tensile properties , Thermal stability , X-ray diffraction , Biodegradable composite films
- Type: Article
- Identifier: uj:4813 , ISSN 1563-5341 , http://hdl.handle.net/10210/12254
- Description: Biodegradable composite films of poly(lactic acid) (PLA)=eggshell powder (ESP) were prepared by the composite film casting method using chloroform as the solvent. ESP was loaded in PLA in 1 to 5 wt.%. The films were subjected to tensile, FT-IR spectral, thermogravimetric, X-ray, and microscopic analyses. The tensile strength and modulus of the composite films were found to be higher than those of PLA and increased with ESP content up to 4 wt.% and then decreased. A reverse trend was observed in the case of percentage elongation at break. The X-ray diffractograms of the composite films indicated an increase in crystallinity with ESP content. The optical micrographs indicated uniform distribution of ESP particles in the composite films. However, the fractographs indicated agglomeration of ESP particles at 5 wt.% loading. The FT-IR spectra revealed no specific interactions between PLA and ESP. The thermal stability of the composite films increased with ESP content.
- Full Text:
- Authors: Ashok, B. , Naresh, S. , Reddy, K. Obi , Madhukar, K. , Cai, J. , Zhang, L. , Rajulu, A. Varada
- Date: 2014
- Subjects: Eggshell powder , Poly(lactic acid) , Tensile properties , Thermal stability , X-ray diffraction , Biodegradable composite films
- Type: Article
- Identifier: uj:4813 , ISSN 1563-5341 , http://hdl.handle.net/10210/12254
- Description: Biodegradable composite films of poly(lactic acid) (PLA)=eggshell powder (ESP) were prepared by the composite film casting method using chloroform as the solvent. ESP was loaded in PLA in 1 to 5 wt.%. The films were subjected to tensile, FT-IR spectral, thermogravimetric, X-ray, and microscopic analyses. The tensile strength and modulus of the composite films were found to be higher than those of PLA and increased with ESP content up to 4 wt.% and then decreased. A reverse trend was observed in the case of percentage elongation at break. The X-ray diffractograms of the composite films indicated an increase in crystallinity with ESP content. The optical micrographs indicated uniform distribution of ESP particles in the composite films. However, the fractographs indicated agglomeration of ESP particles at 5 wt.% loading. The FT-IR spectra revealed no specific interactions between PLA and ESP. The thermal stability of the composite films increased with ESP content.
- Full Text:
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