Previous studies investigating manufacture of phosphate-based glass fibres from glasses fixed wit... more Previous studies investigating manufacture of phosphate-based glass fibres from glasses fixed with P 2 O 5 content less than 50 mol% showed that continuous manufacture without breakage was very difficult. In this study, nine phosphate-based glass formulations from the system P 2 O 5 -CaO-Na 2 O-MgO-B 2 O 3 were prepared with P 2 O 5 contents fixed at 40, 45 and 50 mol%, where Na 2 O was replaced by 5 and 10 mol% B 2 O 3 and MgO and CaO were fixed to 24 and 16 mol%, respectively. The effect of B 2 O 3 addition on the fibre drawing, fibre mechanical properties and dissolution behaviour was investigated. It was found that addition of 5 and 10 mol% B 2 O 3 enabled successful drawing of continuous fibres from glasses with phosphate (P 2 O 5 ) contents fixed at 40, 45 and 50 mol%. The mechanical properties of the fibres were found to significantly increase with increasing B 2 O 3 content. The highest tensile strength (1200 AE 130 MPa) was recorded for 45P 2 O 5 -16CaO-5Na 2 O-24MgO-10B 2 O 3 glass fibres. The fibres were annealed, and a comparison of the mechanical properties and mode of degradation of annealed and non-annealed fibres were investigated. A decrease in tensile strength and an increase in tensile modulus were observed for the annealed fibres. An assessment of the change in mechanical properties of both the annealed and non-annealed fibres was performed in phosphate-buffered saline (PBS) at 37 C for 28 and 60 days, respectively. Initial loss of mechanical properties due to annealing was found to be recovered with degradation. The B 2 O 3 -containing glass fibres were found to degrade at a much slower rate as compared to the non-B 2 O 3 -containing fibres. Both annealed and non-annealed fibres exhibited a peeling effect of the fibre's outer layer during degradation.
In this study eight different phosphate-based glass compositions were prepared by melt-quenching:... more In this study eight different phosphate-based glass compositions were prepared by melt-quenching: four in the (P 2 O 5 ) 45 -(CaO) 16 -(Na 2 O) 15− -(MgO) 24 -(B 2 O 3 ) system and four in the system (P 2 O 5 ) 50 -(CaO) 16 -(Na 2 O) 10− -(MgO) 24 -(B 2 O 3 ) , where = 0, 1, 5 and 10 mol%. The effect of B 2 O 3 addition on the thermal properties, density, molar volume, dissolution rates, and cytocompatibility were studied for both glass systems. Addition of B 2 O 3 increased the glass transition ( g ), crystallisation ( c ), melting ( m ), Liquidus ( L ) and dilatometric softening ( d ) temperature and molar volume ( m ). The thermal expansion coefficient ( ) and density ( ) were seen to decrease. An assessment of the thermal stability of the glasses was made in terms of their processing window (crystallisation onset, c,ons minus glass transition temperature, g ), and an increase in the processing window was observed with increasing B 2 O 3 content. Degradation studies of the glasses revealed that the rates decreased with increasing B 2 O 3 content and a decrease in degradation rates was also observed as the P 2 O 5 content reduced from 50 to 45 mol%. MG63 osteoblast-like cells cultured in direct contact with the glass samples for 14 days revealed comparative data to the positive control for the cell metabolic activity, proliferation, ALP activity, and morphology for glasses containing up to 5 mol% of B 2 O 3 .
Chitosan (1wt%, in 2% aqueous acetic acid solution) and starch (1wt%, in deionised water) were di... more Chitosan (1wt%, in 2% aqueous acetic acid solution) and starch (1wt%, in deionised water) were dissolved and mixed in different proportions (20–80wt% chitosan) then films were prepared by casting. Tensile strength and elongation at break of the 50% chitosan containing starch-based films were found to be 47MPa and 16%, respectively. It was revealed that with the increase of chitosan in
Methylcellulose (MC)-based films were prepared by solution casting from its 1% aqueous suspension... more Methylcellulose (MC)-based films were prepared by solution casting from its 1% aqueous suspension containing 0.25% glycerol. Trimethylolpropane trimethacrylate (TMPTMA) monomer (0.1-2% by wt) along with the glycerol was added to the MC suspension. The films were cast and irradiated from a radiation dose varied from 0.1 to 10 kGy. Then the mechanical properties such as tensile strength (TS), tensile modulus (TM), and elongation at break (Eb) and barrier properties of the films were evaluated. The highest TS (47.88 PMa) and TM (1791.50 MPa) of the films were found by using 0.1% monomer at 5 kGy dose. The lowest water vapor permeability (WVP) of the films was found to be 5.57 g·mm/m(2)·day·kPa (at 0.1% monomer and 5 kGy dose), which is 12.14% lower than control MC-based films. Molecular interactions due to incorporation of TMPTMA were supported by FTIR spectroscopy. A band at 1720 cm(-1) was observed due to the addition of TMPTMA in MC-based films, which indicated the typical (C═O) carbonyl stretching. For the further improvement of the mechanical and barrier properties of the film, 0.025-1% nanocrystalline cellulose (NCC) was added to the MC-based suspension containing 1% TMPTMA. Addition of NCC led to a significant improvement in the mechanical and barrier properties. The novelty of this investigation was to graft insoluble monomer using γ radiation with MC-based films and use of biodegradable NCC as the reinforcing agent.
International Journal of Polymeric Materials, 2011
Gelatin-based polyvinyl alcohol (PVA) films were prepared (using a casting process) by mixing aqu... more Gelatin-based polyvinyl alcohol (PVA) films were prepared (using a casting process) by mixing aqueous solutions of gelatin and PVA in different ratios. Monomer 1, 4-butanediol diacrylate (BDDA) was dissolved in methanol. Films containing 95% gelatin þ 5% PVA were soaked in 3% BDDA monomer (w=w). These films were then 20 irradiated under gamma radiation ( 60 Co) at different doses (50-500 krad) at a dose rate of 350 krad=h. The physico-mechanical and thermal properties of these films were evaluated. It was evident that 5% PVA-containing gelatin blend film exhibited the highest tensile strength (TS) value at 50 krad (51 MPa), which was 46% higher than that of non-irradiated blend films. It was also found that incorporation of PVA 25 significantly reduced the TS value of the blend films compared to the raw film, whereas elongation at break (Eb) value was increased. A significant improvement of the blend films was also confirmed by thermo gravimetric analysis (TGA) and
Journal of Reinforced Plastics and Composites, 2010
Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabrica... more Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, and impact strength of the composites were found to be 48 MPa, 2.5 GPa, 56 MPa, 4.5 GPa, and 18 kJ/m 2 , respectively. Then E-glass fiber (woven)-reinforced polypropylenebased composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the jute-based composites. It was revealed that E-glass fiber-based composites had almost double the mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 2.13 and 4.66 MPa, respectively, measured using the single-fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were studied by scanning electron microscope and the results revealed poor fiber matrix adhesion for jute-based composites when compared to that of the E-glass fiber composites.
Journal of Reinforced Plastics and Composites, 2010
Polypropylene (PP) matrix synthetic phosphate based degradable fiber reinforced unidirectional co... more Polypropylene (PP) matrix synthetic phosphate based degradable fiber reinforced unidirectional composites (10% fiber by weight) were fabricated by compression molding. Tensile strength (TS), tensile modulus (TM), elongation at break (%), bending strength (BS), bending modulus (BM), and impact strength (IS) were found to be 38 MPa, 1.5 GPa, 12%, 44 MPa, 4.9 GPa, and 7.58 kJ/m 2 respectively. Degradation tests of the fibers and composites were performed for six months in aqueous medium at room temperature (258C). After six months, the mechanical properties of the composites retained almost 80% of their original properties. The interfacial shear strength (IFSS) of the composites were also measured by single fiber fragmentation test (SFFT). The IFSS of the composite system was found 5.9 MPa that indicated good fiber matrix adhesion.
A systematic study has been carried out to investigate matrix properties by introducing micro- an... more A systematic study has been carried out to investigate matrix properties by introducing micro- and nanosized SiC fillers into an epoxy matrix. The study has revealed that with equal amount of loading; nanoparticle infusion brings about superior thermal and mechanical properties to the matrix than what is usually given by the microfillers infusion. The nanophased matrix is then utilized in
ABSTRACT Coir fibers (Cocos nucifera) were treated with 1-ethyl-2-pyrrolidone (1-E-2-P) mixed wit... more ABSTRACT Coir fibers (Cocos nucifera) were treated with 1-ethyl-2-pyrrolidone (1-E-2-P) mixed with methanol (MeOH) under UV radiation. A series of solutions of different concentrations of 1-E-2-P in methanol along with a photoinitiator, Darocur-1173, were prepared. Monomer concentration, soaking time, and radiation dose were optimized in terms of grafting and mechanical properties. Ten percent 1-E-2-P, 6 min soaking time, and a 15th pass of radiation produced higher tensile strength (53 %) and elongation at break (230 %) than those of virgin fiber, as well as the highest grafting value (4.9 %). The effect of additives (1 %), such as urea and silane (3-trimethoxysilyl propyl methacrylate) on the properties of coir fiber was studied. Among the additives used, silane showed the best performance. For further improvement of the properties, the fibers were treated with alkali (potassium hydroxide) solution of different temperatures (0–60 °C). A 10 % alkali-treated fiber showed the best properties such as grafting (6.2 %), tensile strength (72 %) and elongation at break (330 %) over virgin fiber. The silane-treated fiber produced the minimum loss of the properties, as well as a lower water uptake than those of the untreated one. The effect of simulating weathering on the degradation properties of samples was also performed.
Previous studies investigating manufacture of phosphate-based glass fibres from glasses fixed wit... more Previous studies investigating manufacture of phosphate-based glass fibres from glasses fixed with P 2 O 5 content less than 50 mol% showed that continuous manufacture without breakage was very difficult. In this study, nine phosphate-based glass formulations from the system P 2 O 5 -CaO-Na 2 O-MgO-B 2 O 3 were prepared with P 2 O 5 contents fixed at 40, 45 and 50 mol%, where Na 2 O was replaced by 5 and 10 mol% B 2 O 3 and MgO and CaO were fixed to 24 and 16 mol%, respectively. The effect of B 2 O 3 addition on the fibre drawing, fibre mechanical properties and dissolution behaviour was investigated. It was found that addition of 5 and 10 mol% B 2 O 3 enabled successful drawing of continuous fibres from glasses with phosphate (P 2 O 5 ) contents fixed at 40, 45 and 50 mol%. The mechanical properties of the fibres were found to significantly increase with increasing B 2 O 3 content. The highest tensile strength (1200 AE 130 MPa) was recorded for 45P 2 O 5 -16CaO-5Na 2 O-24MgO-10B 2 O 3 glass fibres. The fibres were annealed, and a comparison of the mechanical properties and mode of degradation of annealed and non-annealed fibres were investigated. A decrease in tensile strength and an increase in tensile modulus were observed for the annealed fibres. An assessment of the change in mechanical properties of both the annealed and non-annealed fibres was performed in phosphate-buffered saline (PBS) at 37 C for 28 and 60 days, respectively. Initial loss of mechanical properties due to annealing was found to be recovered with degradation. The B 2 O 3 -containing glass fibres were found to degrade at a much slower rate as compared to the non-B 2 O 3 -containing fibres. Both annealed and non-annealed fibres exhibited a peeling effect of the fibre's outer layer during degradation.
In this study eight different phosphate-based glass compositions were prepared by melt-quenching:... more In this study eight different phosphate-based glass compositions were prepared by melt-quenching: four in the (P 2 O 5 ) 45 -(CaO) 16 -(Na 2 O) 15− -(MgO) 24 -(B 2 O 3 ) system and four in the system (P 2 O 5 ) 50 -(CaO) 16 -(Na 2 O) 10− -(MgO) 24 -(B 2 O 3 ) , where = 0, 1, 5 and 10 mol%. The effect of B 2 O 3 addition on the thermal properties, density, molar volume, dissolution rates, and cytocompatibility were studied for both glass systems. Addition of B 2 O 3 increased the glass transition ( g ), crystallisation ( c ), melting ( m ), Liquidus ( L ) and dilatometric softening ( d ) temperature and molar volume ( m ). The thermal expansion coefficient ( ) and density ( ) were seen to decrease. An assessment of the thermal stability of the glasses was made in terms of their processing window (crystallisation onset, c,ons minus glass transition temperature, g ), and an increase in the processing window was observed with increasing B 2 O 3 content. Degradation studies of the glasses revealed that the rates decreased with increasing B 2 O 3 content and a decrease in degradation rates was also observed as the P 2 O 5 content reduced from 50 to 45 mol%. MG63 osteoblast-like cells cultured in direct contact with the glass samples for 14 days revealed comparative data to the positive control for the cell metabolic activity, proliferation, ALP activity, and morphology for glasses containing up to 5 mol% of B 2 O 3 .
Chitosan (1wt%, in 2% aqueous acetic acid solution) and starch (1wt%, in deionised water) were di... more Chitosan (1wt%, in 2% aqueous acetic acid solution) and starch (1wt%, in deionised water) were dissolved and mixed in different proportions (20–80wt% chitosan) then films were prepared by casting. Tensile strength and elongation at break of the 50% chitosan containing starch-based films were found to be 47MPa and 16%, respectively. It was revealed that with the increase of chitosan in
Methylcellulose (MC)-based films were prepared by solution casting from its 1% aqueous suspension... more Methylcellulose (MC)-based films were prepared by solution casting from its 1% aqueous suspension containing 0.25% glycerol. Trimethylolpropane trimethacrylate (TMPTMA) monomer (0.1-2% by wt) along with the glycerol was added to the MC suspension. The films were cast and irradiated from a radiation dose varied from 0.1 to 10 kGy. Then the mechanical properties such as tensile strength (TS), tensile modulus (TM), and elongation at break (Eb) and barrier properties of the films were evaluated. The highest TS (47.88 PMa) and TM (1791.50 MPa) of the films were found by using 0.1% monomer at 5 kGy dose. The lowest water vapor permeability (WVP) of the films was found to be 5.57 g·mm/m(2)·day·kPa (at 0.1% monomer and 5 kGy dose), which is 12.14% lower than control MC-based films. Molecular interactions due to incorporation of TMPTMA were supported by FTIR spectroscopy. A band at 1720 cm(-1) was observed due to the addition of TMPTMA in MC-based films, which indicated the typical (C═O) carbonyl stretching. For the further improvement of the mechanical and barrier properties of the film, 0.025-1% nanocrystalline cellulose (NCC) was added to the MC-based suspension containing 1% TMPTMA. Addition of NCC led to a significant improvement in the mechanical and barrier properties. The novelty of this investigation was to graft insoluble monomer using γ radiation with MC-based films and use of biodegradable NCC as the reinforcing agent.
International Journal of Polymeric Materials, 2011
Gelatin-based polyvinyl alcohol (PVA) films were prepared (using a casting process) by mixing aqu... more Gelatin-based polyvinyl alcohol (PVA) films were prepared (using a casting process) by mixing aqueous solutions of gelatin and PVA in different ratios. Monomer 1, 4-butanediol diacrylate (BDDA) was dissolved in methanol. Films containing 95% gelatin þ 5% PVA were soaked in 3% BDDA monomer (w=w). These films were then 20 irradiated under gamma radiation ( 60 Co) at different doses (50-500 krad) at a dose rate of 350 krad=h. The physico-mechanical and thermal properties of these films were evaluated. It was evident that 5% PVA-containing gelatin blend film exhibited the highest tensile strength (TS) value at 50 krad (51 MPa), which was 46% higher than that of non-irradiated blend films. It was also found that incorporation of PVA 25 significantly reduced the TS value of the blend films compared to the raw film, whereas elongation at break (Eb) value was increased. A significant improvement of the blend films was also confirmed by thermo gravimetric analysis (TGA) and
Journal of Reinforced Plastics and Composites, 2010
Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabrica... more Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, and impact strength of the composites were found to be 48 MPa, 2.5 GPa, 56 MPa, 4.5 GPa, and 18 kJ/m 2 , respectively. Then E-glass fiber (woven)-reinforced polypropylenebased composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the jute-based composites. It was revealed that E-glass fiber-based composites had almost double the mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 2.13 and 4.66 MPa, respectively, measured using the single-fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were studied by scanning electron microscope and the results revealed poor fiber matrix adhesion for jute-based composites when compared to that of the E-glass fiber composites.
Journal of Reinforced Plastics and Composites, 2010
Polypropylene (PP) matrix synthetic phosphate based degradable fiber reinforced unidirectional co... more Polypropylene (PP) matrix synthetic phosphate based degradable fiber reinforced unidirectional composites (10% fiber by weight) were fabricated by compression molding. Tensile strength (TS), tensile modulus (TM), elongation at break (%), bending strength (BS), bending modulus (BM), and impact strength (IS) were found to be 38 MPa, 1.5 GPa, 12%, 44 MPa, 4.9 GPa, and 7.58 kJ/m 2 respectively. Degradation tests of the fibers and composites were performed for six months in aqueous medium at room temperature (258C). After six months, the mechanical properties of the composites retained almost 80% of their original properties. The interfacial shear strength (IFSS) of the composites were also measured by single fiber fragmentation test (SFFT). The IFSS of the composite system was found 5.9 MPa that indicated good fiber matrix adhesion.
A systematic study has been carried out to investigate matrix properties by introducing micro- an... more A systematic study has been carried out to investigate matrix properties by introducing micro- and nanosized SiC fillers into an epoxy matrix. The study has revealed that with equal amount of loading; nanoparticle infusion brings about superior thermal and mechanical properties to the matrix than what is usually given by the microfillers infusion. The nanophased matrix is then utilized in
ABSTRACT Coir fibers (Cocos nucifera) were treated with 1-ethyl-2-pyrrolidone (1-E-2-P) mixed wit... more ABSTRACT Coir fibers (Cocos nucifera) were treated with 1-ethyl-2-pyrrolidone (1-E-2-P) mixed with methanol (MeOH) under UV radiation. A series of solutions of different concentrations of 1-E-2-P in methanol along with a photoinitiator, Darocur-1173, were prepared. Monomer concentration, soaking time, and radiation dose were optimized in terms of grafting and mechanical properties. Ten percent 1-E-2-P, 6 min soaking time, and a 15th pass of radiation produced higher tensile strength (53 %) and elongation at break (230 %) than those of virgin fiber, as well as the highest grafting value (4.9 %). The effect of additives (1 %), such as urea and silane (3-trimethoxysilyl propyl methacrylate) on the properties of coir fiber was studied. Among the additives used, silane showed the best performance. For further improvement of the properties, the fibers were treated with alkali (potassium hydroxide) solution of different temperatures (0–60 °C). A 10 % alkali-treated fiber showed the best properties such as grafting (6.2 %), tensile strength (72 %) and elongation at break (330 %) over virgin fiber. The silane-treated fiber produced the minimum loss of the properties, as well as a lower water uptake than those of the untreated one. The effect of simulating weathering on the degradation properties of samples was also performed.
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