Poly lactic acid (PLA)—chemically treated fiber of Luffa cylindrica (LC) composites were fabricated by micro-compounding followed by injection molding method. Before reinforcement, LC fibers were exposed to chemical ...Poly lactic acid (PLA)—chemically treated fiber of Luffa cylindrica (LC) composites were fabricated by micro-compounding followed by injection molding method. Before reinforcement, LC fibers were exposed to chemical treatment like alkali treatment, bleaching and acid hydrolysis. The chemically treated LC fibers were then modified with Ca salts to explore their uses in bio medical industries. Thermal stability of chemically extracted cellulose fibers of LC and PLA composites reinforced with 2 wt%, 5 wt% and 10 wt% LC fibers were studied by thermo gravimetric analysis (TGA) in the temperature range from 30℃ to 700℃. Better interfacial bonding between fiber and matrix was evidenced by increased thermal stability of composites due to incorporation of fiber. Crystallization and melting behavior of PLA composites were studied in the temperature range from 30℃ to 170℃ at heating rate of 10°/minute. The crystallization temperature and crystallization enthalpy increased up to 2 wt% of LC fiber content and gradually decreased with further increase of fiber content in the composites. Double melting peaks were observed for all composite samples and possible explanations were suggested on the basis of different crystalline structure of PLA and melt crystallization phenomena.展开更多
Dynamic mechanical behaviour of resorcinol-formaldehyde matrix and its composites reinforced with natural fibers of Luffa cylindrica (LC) has been studied. The effects of fiber loading, alkali treatment on fiber, temp...Dynamic mechanical behaviour of resorcinol-formaldehyde matrix and its composites reinforced with natural fibers of Luffa cylindrica (LC) has been studied. The effects of fiber loading, alkali treatment on fiber, temperature and frequency on storage modulus and mechanical-loss factor of the composites were studied. The dynamic mechanical behaviour of the composites and pure matrix has been investigated in the frequency range from 0.1 Hz to 10 Hz and temperature range from 26℃ to 100℃. The experimental results show that the values of storage modulus of the composites increase with increase in fiber loading. The storage modulus of treated LC fiber composites were found to be enhanced when compared with the untreated fiber composites. It was also found that mechanical-loss factor was more when untreated LC fibers were incorporated in the composites and decreased with the incorporation of treated LC fiber. The storage modulus of all the composites increased with frequency but decreased with rise of temperature. The glass transition temperature of the composites was evaluated from the peaks of tan delta variations.展开更多
In view of biomedical applications of cellulose fibers in orthopedics, dentistry and reconstructive surgery, Luffa cylindrica (LC), a local forest product of Orissa, India, has been used for preparation of alkali trea...In view of biomedical applications of cellulose fibers in orthopedics, dentistry and reconstructive surgery, Luffa cylindrica (LC), a local forest product of Orissa, India, has been used for preparation of alkali treated LC fiber modified with calcium carbonate and calcium phosphate separately by following standard procedures. FTIR and Raman spectra were obtained for these samples at wavelength range 500 - 4000 cm–1 and 300 - 3000 cm–1 respectively. Lattice structures of cellulose i.e., crystalline cellulose and amorphous cellulose were detected using Raman spectroscopy and discussed. The property of cellulose such as its degree of crystallinity was determined from intensity of FT IR peaks and was found to be 74.12%. The presence of calcite and hydroxy apatite, polymorphs of calcium carbonate and calcium phosphate respectively were confirmed in the treated modified LC fibers which can be used as bioactive materials.展开更多
The influence of cellulose nano fibers extracted from the fruit of luffa cylindrica (LC) on the tensile, flexural and impact properties of composite materials using poly lactic acid (PLA) processed by micro compoundin...The influence of cellulose nano fibers extracted from the fruit of luffa cylindrica (LC) on the tensile, flexural and impact properties of composite materials using poly lactic acid (PLA) processed by micro compounding and injection molding was studied. Preliminary results suggested promising mechanical properties. The impact strength, tensile strength and flexural strength of the composites increased with incorporation of very low content of LC fiber up to 2 wt%. But when the wt of LC fiber in the composite increased (5 wt% and 10 wt%), mechanical strength of the composites reduced probably due to agglomeration of cellulose fibers. However, modulus of composites was enhanced with increase in wt of fiber content in the composites. Before reinforcement, the LC fibers were modified with calcium phosphate in order to explore the possibilities of using these composites in biomedical industries. The novelty of this work is that there is no use of compatiblizer and coupling agent during the processing so that the cost of processing is reduced.展开更多
文摘Poly lactic acid (PLA)—chemically treated fiber of Luffa cylindrica (LC) composites were fabricated by micro-compounding followed by injection molding method. Before reinforcement, LC fibers were exposed to chemical treatment like alkali treatment, bleaching and acid hydrolysis. The chemically treated LC fibers were then modified with Ca salts to explore their uses in bio medical industries. Thermal stability of chemically extracted cellulose fibers of LC and PLA composites reinforced with 2 wt%, 5 wt% and 10 wt% LC fibers were studied by thermo gravimetric analysis (TGA) in the temperature range from 30℃ to 700℃. Better interfacial bonding between fiber and matrix was evidenced by increased thermal stability of composites due to incorporation of fiber. Crystallization and melting behavior of PLA composites were studied in the temperature range from 30℃ to 170℃ at heating rate of 10°/minute. The crystallization temperature and crystallization enthalpy increased up to 2 wt% of LC fiber content and gradually decreased with further increase of fiber content in the composites. Double melting peaks were observed for all composite samples and possible explanations were suggested on the basis of different crystalline structure of PLA and melt crystallization phenomena.
文摘Dynamic mechanical behaviour of resorcinol-formaldehyde matrix and its composites reinforced with natural fibers of Luffa cylindrica (LC) has been studied. The effects of fiber loading, alkali treatment on fiber, temperature and frequency on storage modulus and mechanical-loss factor of the composites were studied. The dynamic mechanical behaviour of the composites and pure matrix has been investigated in the frequency range from 0.1 Hz to 10 Hz and temperature range from 26℃ to 100℃. The experimental results show that the values of storage modulus of the composites increase with increase in fiber loading. The storage modulus of treated LC fiber composites were found to be enhanced when compared with the untreated fiber composites. It was also found that mechanical-loss factor was more when untreated LC fibers were incorporated in the composites and decreased with the incorporation of treated LC fiber. The storage modulus of all the composites increased with frequency but decreased with rise of temperature. The glass transition temperature of the composites was evaluated from the peaks of tan delta variations.
文摘In view of biomedical applications of cellulose fibers in orthopedics, dentistry and reconstructive surgery, Luffa cylindrica (LC), a local forest product of Orissa, India, has been used for preparation of alkali treated LC fiber modified with calcium carbonate and calcium phosphate separately by following standard procedures. FTIR and Raman spectra were obtained for these samples at wavelength range 500 - 4000 cm–1 and 300 - 3000 cm–1 respectively. Lattice structures of cellulose i.e., crystalline cellulose and amorphous cellulose were detected using Raman spectroscopy and discussed. The property of cellulose such as its degree of crystallinity was determined from intensity of FT IR peaks and was found to be 74.12%. The presence of calcite and hydroxy apatite, polymorphs of calcium carbonate and calcium phosphate respectively were confirmed in the treated modified LC fibers which can be used as bioactive materials.
文摘The influence of cellulose nano fibers extracted from the fruit of luffa cylindrica (LC) on the tensile, flexural and impact properties of composite materials using poly lactic acid (PLA) processed by micro compounding and injection molding was studied. Preliminary results suggested promising mechanical properties. The impact strength, tensile strength and flexural strength of the composites increased with incorporation of very low content of LC fiber up to 2 wt%. But when the wt of LC fiber in the composite increased (5 wt% and 10 wt%), mechanical strength of the composites reduced probably due to agglomeration of cellulose fibers. However, modulus of composites was enhanced with increase in wt of fiber content in the composites. Before reinforcement, the LC fibers were modified with calcium phosphate in order to explore the possibilities of using these composites in biomedical industries. The novelty of this work is that there is no use of compatiblizer and coupling agent during the processing so that the cost of processing is reduced.
