M. Mishra, A. Narayan, R. Singh, R. S. Yadav, N. Nidhi, A. C. Pandey
ZnO codoped with Ca and Mg in various proportions was prepared by a chemical method and annealed at 600 C. The structural and optical properties of these oxide samples were systematically studied by XRD, SEM, EDS, and PL spectrometer. XRD pattern shows a hexagonal wurtzite structure. The size of particle as shown by XRD machine and calculated by Scherer’s formula is found in the nano range. The formation of particles showed that they were polycrystalline. Due to larger ionic and covalent radii of Ca than those of Zinc, a lattice deformation occurs with the development of strain field. New phases were observed in XRD pattern of few samples ZnO-2.2 and ZnO-2.4. SEM micrograph shows the formation of nanoparticles. EDS study confirms the codoping of ZnO with Ca and Mg. Optical properties like photoluminescence emission showed a blue shift in peak wavelength. General conductivity and photoconductivity were found high in samples containing certain proportion of Ca and Mg in comparison with pure ZnO.
{"title":"Study of Structural and Optoelectronic Properties of ZnO Codoped with Ca and Mg","authors":"M. Mishra, A. Narayan, R. Singh, R. S. Yadav, N. Nidhi, A. C. Pandey","doi":"10.1155/2013/405147","DOIUrl":"https://doi.org/10.1155/2013/405147","url":null,"abstract":"ZnO codoped with Ca and Mg in various proportions was prepared by a chemical method and annealed at 600 C. The structural and optical properties of these oxide samples were systematically studied by XRD, SEM, EDS, and PL spectrometer. XRD pattern shows a hexagonal wurtzite structure. The size of particle as shown by XRD machine and calculated by Scherer’s formula is found in the nano range. The formation of particles showed that they were polycrystalline. Due to larger ionic and covalent radii of Ca than those of Zinc, a lattice deformation occurs with the development of strain field. New phases were observed in XRD pattern of few samples ZnO-2.2 and ZnO-2.4. SEM micrograph shows the formation of nanoparticles. EDS study confirms the codoping of ZnO with Ca and Mg. Optical properties like photoluminescence emission showed a blue shift in peak wavelength. General conductivity and photoconductivity were found high in samples containing certain proportion of Ca and Mg in comparison with pure ZnO.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"38 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2013-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83228826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Nagaraj, Vikram Singh, H. S. Jayanna, K. M. Balakrishna, R. Damle
Total Dose Effect (TDE) on solid state devices is of serious concern as it changes the electrical properties leading to degradation of the devices and failure of the systems associated with them. Ionization caused due to TDE in commercial P-channel Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) has been studied, where the failure mechanism is found to be mainly a result of the changes in the oxide properties and the surface effects at the channel beneath the gate oxide. The threshold voltage of the MOSFETs was found to shift from −0.69 V to −2.41 V for a total gamma dose of 1 Mrad. The net negative threshold shifts in the irradiated devices reveal the major contribution of oxide trapped charges to device degradation. The radiation induced oxide and interface charge densities were estimated through subthreshold measurements, and the trap densities were found to increase by one order in magnitude after a total gamma dose of 1 Mrad. Other parameters like transconductance, subthreshold swing, and drain saturation current are also investigated as a function of gamma dose.
{"title":"60Co-Gamma Ray Induced Total Dose Effects on P-Channel MOSFETs","authors":"S. Nagaraj, Vikram Singh, H. S. Jayanna, K. M. Balakrishna, R. Damle","doi":"10.1155/2013/465905","DOIUrl":"https://doi.org/10.1155/2013/465905","url":null,"abstract":"Total Dose Effect (TDE) on solid state devices is of serious concern as it changes the electrical properties leading to degradation of the devices and failure of the systems associated with them. Ionization caused due to TDE in commercial P-channel Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) has been studied, where the failure mechanism is found to be mainly a result of the changes in the oxide properties and the surface effects at the channel beneath the gate oxide. The threshold voltage of the MOSFETs was found to shift from −0.69 V to −2.41 V for a total gamma dose of 1 Mrad. The net negative threshold shifts in the irradiated devices reveal the major contribution of oxide trapped charges to device degradation. The radiation induced oxide and interface charge densities were estimated through subthreshold measurements, and the trap densities were found to increase by one order in magnitude after a total gamma dose of 1 Mrad. Other parameters like transconductance, subthreshold swing, and drain saturation current are also investigated as a function of gamma dose.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"133 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2013-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89436168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Choudary, P. Prameela, M. C. Varma, A. M. Kumar, K. Rao
In this communication, Co/Cu substituted Ni-Zn ferrites processed through sol-gel synthesis using polyethylene glycol (PEG) as a chelating agent are studied, intending to aid in understanding and choosing the optimum ferrite material for high frequency applications. Lattice constant and average crystallite size have been estimated from FWHM of the X-ray diffraction peaks, and these parameters are understood by considering the ionic radii of the substituted as well as the replacing ions. Observed variations in saturation magnetization and initial permeability for these ferrites have been explained on the basis of anisotropy contribution for cobalt and segregation of copper at grain boundaries evident from scanning electron micrographs.
{"title":"Contribution to Analysis of Co/Cu Substituted Ni-Zn Ferrites","authors":"G. Choudary, P. Prameela, M. C. Varma, A. M. Kumar, K. Rao","doi":"10.1155/2013/350707","DOIUrl":"https://doi.org/10.1155/2013/350707","url":null,"abstract":"In this communication, Co/Cu substituted Ni-Zn ferrites processed through sol-gel synthesis using polyethylene glycol (PEG) as a chelating agent are studied, intending to aid in understanding and choosing the optimum ferrite material for high frequency applications. Lattice constant and average crystallite size have been estimated from FWHM of the X-ray diffraction peaks, and these parameters are understood by considering the ionic radii of the substituted as well as the replacing ions. Observed variations in saturation magnetization and initial permeability for these ferrites have been explained on the basis of anisotropy contribution for cobalt and segregation of copper at grain boundaries evident from scanning electron micrographs.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"1 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2013-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83162168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Srinivasarao, G. Srinivasarao, K. Madhuri, K. Murthy, P. Mukhopadhyay
The ZnO and Mo:ZnO thin films were deposited by radio frequency magnetron sputtering on quartz and intrinsic silicon (100) substrates at a fixed combined partial pressure mbar of Ar
采用射频磁控溅射法在石英和本征硅(100)衬底上制备了ZnO和Mo:ZnO薄膜
{"title":"Preparation and Characterization of R.F. Magnetron Sputtered Mo:ZnO Thin Films","authors":"K. Srinivasarao, G. Srinivasarao, K. Madhuri, K. Murthy, P. Mukhopadhyay","doi":"10.1155/2013/684730","DOIUrl":"https://doi.org/10.1155/2013/684730","url":null,"abstract":"The ZnO and Mo:ZnO thin films were deposited by radio frequency magnetron sputtering on quartz and intrinsic silicon (100) substrates at a fixed combined partial pressure mbar of Ar","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"32 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2013-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85027826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The sorption of Ni(II) onto grape shell ash (GSA) was studied by performing batch kinetic sorption experiments. The influences of major parameters in Nickel(II) ions sorption on GS such as initial of pH, initial concentration of Ni(II) ions, the initial temperatures of solution, and contact time were investigated. The maximum increase in the rate of sorption of Ni(II) ions on GS was observed at an initial pH = 5, initial concentration of nickel 50 mgL−1, temperature of solution (328 K), and min. The rate constants and the equilibrium sorption capacities were calculated. The results indicate that the sorption process follows the second-order kinetics and the values of rate constants were found to be 0.224, 0.402, 0.193 and 0.123 min−1 at 298, 308, 318, and 328 K, respectively. The values of correlation coefficients for the adsorption of Ni(II) on GSA from all the systems were found to be 0.999, and the values of predicted equilibrium sorption capacities showed good agreement with the experimental equilibrium uptake values. The thermodynamic parameters (, , and ) of the adsorption process were calculated, and these parameters showed that the adsorption process is spontaneous.
{"title":"The Sorption of Ni(II) by Grape Shell Ash from Aqueous Solution: Kinetic and Thermodynamic Studies","authors":"N. Ghasemi, M. Ghasemi, Y. Khosravi-fard","doi":"10.1155/2013/248138","DOIUrl":"https://doi.org/10.1155/2013/248138","url":null,"abstract":"The sorption of Ni(II) onto grape shell ash (GSA) was studied by performing batch kinetic sorption experiments. The influences of major parameters in Nickel(II) ions sorption on GS such as initial of pH, initial concentration of Ni(II) ions, the initial temperatures of solution, and contact time were investigated. The maximum increase in the rate of sorption of Ni(II) ions on GS was observed at an initial pH = 5, initial concentration of nickel 50 mgL−1, temperature of solution (328 K), and min. The rate constants and the equilibrium sorption capacities were calculated. The results indicate that the sorption process follows the second-order kinetics and the values of rate constants were found to be 0.224, 0.402, 0.193 and 0.123 min−1 at 298, 308, 318, and 328 K, respectively. The values of correlation coefficients for the adsorption of Ni(II) on GSA from all the systems were found to be 0.999, and the values of predicted equilibrium sorption capacities showed good agreement with the experimental equilibrium uptake values. The thermodynamic parameters (, , and ) of the adsorption process were calculated, and these parameters showed that the adsorption process is spontaneous.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"40 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2013-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83009897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Perfect single crystals of cadmium oxalate have been grown using the slow and controlled reaction between cadmium acetate and oxalic acid in agar gel media at ambient temperature, resulting in the formation of insoluble product Cd(COO)2. Different methods for growing crystals were adopted. The optimum conditions were employed in each method by varying the concentration of gel and reactants, gel setting time, and so forth. Prismatic, transparent single crystal about 20 times larger than the crystals obtained in various other methods at the interstitial by adding impurities in the gel was obtained. The grown crystals was characterized with the help of FT-IR studies and triclinic system of crystals were supported with lattice parameters a = 8.803 A0, b = 22.352 A0, c = 5.706 A0, α = 95.74 A0, β = 90.92 A0, γ = 117.01 A0, and V = 994.69 , calculated from X-ray diffractogram.
在琼脂凝胶介质中，采用醋酸镉与草酸在室温下缓慢而可控的反应，制备出完美的草酸镉单晶，形成不溶性产物Cd(COO)2。采用了不同的晶体生长方法。通过改变凝胶和反应物的浓度、凝胶凝结时间等因素，确定了每种方法的最佳条件。通过在凝胶中添加杂质，在间隙处获得的晶体比其他各种方法获得的晶体大20倍左右的棱柱状透明单晶。利用红外光谱(FT-IR)对生长的晶体进行了表征，得到了三斜晶系，晶格参数为a = 8.803 A0, b = 22.352 A0, c = 5.706 A0， α = 95.74 A0， β = 90.92 A0， γ = 117.01 A0, V = 994.69。
{"title":"Nucleation Controlled Growth of Cadmium Oxalate Crystals in Agar Gel and Their Characterization","authors":"P. Dalal","doi":"10.1155/2013/682950","DOIUrl":"https://doi.org/10.1155/2013/682950","url":null,"abstract":"Perfect single crystals of cadmium oxalate have been grown using the slow and controlled reaction between cadmium acetate and oxalic acid in agar gel media at ambient temperature, resulting in the formation of insoluble product Cd(COO)2. Different methods for growing crystals were adopted. The optimum conditions were employed in each method by varying the concentration of gel and reactants, gel setting time, and so forth. Prismatic, transparent single crystal about 20 times larger than the crystals obtained in various other methods at the interstitial by adding impurities in the gel was obtained. The grown crystals was characterized with the help of FT-IR studies and triclinic system of crystals were supported with lattice parameters a = 8.803 A0, b = 22.352 A0, c = 5.706 A0, α = 95.74 A0, β = 90.92 A0, γ = 117.01 A0, and V = 994.69 , calculated from X-ray diffractogram.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"135 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2013-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86361385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Semiconducting thin films of ternary () have been deposited on glass substrate by the simple and economical chemical bath deposition method. We report the deposition and optimization of the solution growth parameters such as temperature, complexing agent, thiourea, and deposition time that maximizes the thickness of the deposited thin film. The X-ray diffraction deposited thin films having cubic structure. The thin films were uniform and adherent to substrate. The composition was found homogeneous and stoichiometric by EDAX analysis.
{"title":"Optimization of Chemical Bath Deposited Mercury Chromium Sulphide Thin Films on Glass Substrate","authors":"H. Patil, S. Borse","doi":"10.1155/2013/694357","DOIUrl":"https://doi.org/10.1155/2013/694357","url":null,"abstract":"Semiconducting thin films of ternary () have been deposited on glass substrate by the simple and economical chemical bath deposition method. We report the deposition and optimization of the solution growth parameters such as temperature, complexing agent, thiourea, and deposition time that maximizes the thickness of the deposited thin film. The X-ray diffraction deposited thin films having cubic structure. The thin films were uniform and adherent to substrate. The composition was found homogeneous and stoichiometric by EDAX analysis.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"103 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2013-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75747438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Controlling the cooling rate during calcination and sintering, phase pure perovskite Ba(Zn1/3Nb2/3)O3 has been prepared by simple solid state reaction route with density >93% at relatively low sintering of 1175°C making it compatible for microwave dielectric applications. The samples are characterized by X-ray diffraction analysis and scanning electron microscopy. The X-ray diffraction shows pure perovskite phase with cubic structure. The lattice constants were obtained a = 4.1032 A. Detailed studies of e′ and e′′ show that the compound exhibits dielectric anomaly at 430°C. Material shows distributed relaxation at higher temperature. Impedance analysis revealed that the impedance is mainly due to the grains. AC conduction activation energies are estimated from Arrhenius plots, and conduction mechanism is discussed.
{"title":"Effect of Process Parameter Optimization in Reducing Sintering Temperature in the Synthesis and Characterization of Ba(Zn1/3Nb2/3)O3","authors":"P. K. Bajpai, K. N. Singh","doi":"10.1155/2013/927908","DOIUrl":"https://doi.org/10.1155/2013/927908","url":null,"abstract":"Controlling the cooling rate during calcination and sintering, phase pure perovskite Ba(Zn1/3Nb2/3)O3 has been prepared by simple solid state reaction route with density >93% at relatively low sintering of 1175°C making it compatible for microwave dielectric applications. The samples are characterized by X-ray diffraction analysis and scanning electron microscopy. The X-ray diffraction shows pure perovskite phase with cubic structure. The lattice constants were obtained a = 4.1032 A. Detailed studies of e′ and e′′ show that the compound exhibits dielectric anomaly at 430°C. Material shows distributed relaxation at higher temperature. Impedance analysis revealed that the impedance is mainly due to the grains. AC conduction activation energies are estimated from Arrhenius plots, and conduction mechanism is discussed.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"76 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2013-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88849981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Singhal, Rimi Sharma, Charanjit Singh, S. Bansal
Multiwalled carbon nanotubes (MWCNTs) were synthesized using arc discharge method at a magnetic field of 430 G and purified using HNO3/H2O2. Transmission electron micrographs revealed that MWCNTs had inner and outer diameter of ~2 nm and ~4 nm, respectively. Raman spectroscopy confirmed formation of MWCNTs showing G-band at 1577 cm−1. ZnFe2O4 and ZnFe2O4/MWCNT were produced using one step hydrothermal method. Powder X-ray diffraction (XRD) confirmed the formation of cubic spinel ZnFe2O4 as well as incorporation of MWCNT into ZnFe2O4. Visible light photocatalytic degradation of methylene blue (MB) was studied using pure ZnFe2O4 and ZnFe2O4/MWCNT. The results showed that ZnFe2O4/MWCNT composite had higher photocatalytic activity as compared to pure ZnFe2O4. After irradiation for 5 hours in the visible light, MB was almost 84% degraded in the presence of ZnFe2O4 photocatalyst, while 99% degradation was observed in case of ZnFe2O4/MWCNT composite. This enhancement in the photocatalytic activity of composite may be attributed to the inhibition of recombination of photogenerated charge carriers.
{"title":"Enhanced Photocatalytic Degradation of Methylene Blue Using /MWCNT Composite Synthesized by Hydrothermal Method","authors":"S. Singhal, Rimi Sharma, Charanjit Singh, S. Bansal","doi":"10.1155/2013/356025","DOIUrl":"https://doi.org/10.1155/2013/356025","url":null,"abstract":"Multiwalled carbon nanotubes (MWCNTs) were synthesized using arc discharge method at a magnetic field of 430 G and purified using HNO3/H2O2. Transmission electron micrographs revealed that MWCNTs had inner and outer diameter of ~2 nm and ~4 nm, respectively. Raman spectroscopy confirmed formation of MWCNTs showing G-band at 1577 cm−1. ZnFe2O4 and ZnFe2O4/MWCNT were produced using one step hydrothermal method. Powder X-ray diffraction (XRD) confirmed the formation of cubic spinel ZnFe2O4 as well as incorporation of MWCNT into ZnFe2O4. Visible light photocatalytic degradation of methylene blue (MB) was studied using pure ZnFe2O4 and ZnFe2O4/MWCNT. The results showed that ZnFe2O4/MWCNT composite had higher photocatalytic activity as compared to pure ZnFe2O4. After irradiation for 5 hours in the visible light, MB was almost 84% degraded in the presence of ZnFe2O4 photocatalyst, while 99% degradation was observed in case of ZnFe2O4/MWCNT composite. This enhancement in the photocatalytic activity of composite may be attributed to the inhibition of recombination of photogenerated charge carriers.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"22 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2013-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72671473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tetrafunctional cardo epoxy resin (EBCF) was cured by using 10 wt% maleic anhydride (MA), pyromellitic dianhydride (PMDA), phthalic anhydride (PA), tetrahydrophthalic anhydride (THPA), tetrabromophthalic anhydride (TBPA), and tetrachlorophthalic anhydride (TCPA) as hardeners at 120°C for 40–105 min (gel time) and then postcured 1 h at 130°C. Gel time is found to depend on the structure of the anhydrides used. Cured samples were found insoluble in common solvents. Cured and uncured EBCF were characterized by FTIR, DSC, and TGA techniques. Cured and uncured resins followed multistep degradation reactions. Kinetic parameters, namely, order of degradation, energy of activation, frequency factor, and entropy change, were determined according to the Anderson-Freeman method and interpreted in light of the nature of hardeners used for curing purpose. The resins followed integral or fractional order degradation kinetics. Complex degradation reactions are due to different types of linkages in cured resins. Both nature and structure of resin and hardeners affected the curing behavior and the resultant thermal properties of the cured resins.
{"title":"Thermal Study of Anhydrides Cured Tetrafunctional Cardo Epoxy Resin","authors":"J. Patel, P. H. Parsania","doi":"10.1155/2013/892371","DOIUrl":"https://doi.org/10.1155/2013/892371","url":null,"abstract":"Tetrafunctional cardo epoxy resin (EBCF) was cured by using 10 wt% maleic anhydride (MA), pyromellitic dianhydride (PMDA), phthalic anhydride (PA), tetrahydrophthalic anhydride (THPA), tetrabromophthalic anhydride (TBPA), and tetrachlorophthalic anhydride (TCPA) as hardeners at 120°C for 40–105 min (gel time) and then postcured 1 h at 130°C. Gel time is found to depend on the structure of the anhydrides used. Cured samples were found insoluble in common solvents. Cured and uncured EBCF were characterized by FTIR, DSC, and TGA techniques. Cured and uncured resins followed multistep degradation reactions. Kinetic parameters, namely, order of degradation, energy of activation, frequency factor, and entropy change, were determined according to the Anderson-Freeman method and interpreted in light of the nature of hardeners used for curing purpose. The resins followed integral or fractional order degradation kinetics. Complex degradation reactions are due to different types of linkages in cured resins. Both nature and structure of resin and hardeners affected the curing behavior and the resultant thermal properties of the cured resins.","PeriodicalId":13278,"journal":{"name":"Indian Journal of Materials Science","volume":"3 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2013-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90752674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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