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Brazilian Journal of Thermal Analysis最新文献

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Effect of graphene content on thermal degradation of PTFE 石墨烯含量对聚四氟乙烯热降解的影响
Brazilian Journal of Thermal Analysis Pub Date : 2017-05-15 DOI: 10.18362/BJTA.V6.I2.12
A. Pienaar, L. J. V. Rooyen, H. Bissett, J. Karger‐Kocsis
{"title":"Effect of graphene content on thermal degradation of PTFE","authors":"A. Pienaar, L. J. V. Rooyen, H. Bissett, J. Karger‐Kocsis","doi":"10.18362/BJTA.V6.I2.12","DOIUrl":"https://doi.org/10.18362/BJTA.V6.I2.12","url":null,"abstract":"In this work we report on the effect of graphene nanoplatelet inclusion on the thermal degradation of polytetrafuoroethylene (PTFE) in nitrogen. PTFE/graphene nanocomposites, containing up to 4 vol% graphene were produced by solution-assisted blending followed by sintering. Decomposition parameters were determined by direct fitting of the Sestak-Berggren equation to the experimental data. It was found that the activation energy of thermal decomposition increased up to as much as 20% and was practically independent of the graphene content in the studied PTFE/graphene nanocomposites. This was attributed to the tortuosity of the graphene layers hampering the diffusion of the gaseous decomposition products.","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"52 1","pages":"7-12"},"PeriodicalIF":0.0,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86697797","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}
引用次数: 5
TGA-FTIR characterisation of bamboo wood, napier grass, pine wood and peach pips for gasification applications 气化用竹材、樟子草、松木和桃核的热重-红外特性分析
Brazilian Journal of Thermal Analysis Pub Date : 2017-03-01 DOI: 10.18362/BJTA.V6I1.8
N. P. Makaringe, I. V. D. Walt, G. Puts, P. Crouse
{"title":"TGA-FTIR characterisation of bamboo wood, napier grass, pine wood and peach pips for gasification applications","authors":"N. P. Makaringe, I. V. D. Walt, G. Puts, P. Crouse","doi":"10.18362/BJTA.V6I1.8","DOIUrl":"https://doi.org/10.18362/BJTA.V6I1.8","url":null,"abstract":"South African \u0000 Nuclear Corporation; the National Research Foundation; and the \u0000 Department of Science and Technology.","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"Suppl 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91143064","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}
引用次数: 3
Thermal, Morphological and Pasting Properties of Binary Mixtures of Starches 淀粉二元混合物的热、形态和糊化性能
Brazilian Journal of Thermal Analysis Pub Date : 2017-03-01 DOI: 10.18362/BJTA.V6I1.10
Cristina Soltovski de Oliveira, T. Colman, L. H. Waiga, C. D. Bet, Egon Schnitzle
{"title":"Thermal, Morphological and Pasting Properties of Binary Mixtures of Starches","authors":"Cristina Soltovski de Oliveira, T. Colman, L. H. Waiga, C. D. Bet, Egon Schnitzle","doi":"10.18362/BJTA.V6I1.10","DOIUrl":"https://doi.org/10.18362/BJTA.V6I1.10","url":null,"abstract":"Mixtures of different starches can present similar properties of chemically modified starches, lowering the industrial cost, besides to be an alternative to meet the industrial demand and consumption of natural products. Therefore, this study aims to evaluate the thermal, pasting properties and morphological characterisation of the starches from cassava ( Manihot esculenta ), sweet potato ( Ipomoea batatas ) and potato ( Solanum tuberosum ), in their native form and their binary mixture. The starches were isolated from aqueous method. TG/DTG showed the highest thermal stability for potato starch as well as their mixtures with sweet potato and cassava. DSC values showed that the gelatinisation enthalpy of potato starch was higher than cassava and sweet potato starches and the mixtures of the starches were physical with low chemical interaction. The mixture of cassava and potato starches showed the highest viscosity value. Relative crystallinity values were similar for cassava starch and sweet potato and lower for potato starch. The lowest values for roughness were obtained for cassava starch and their blends. The results obtained for the mixtures of starch showed an average of those values found for starches in their native form.","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81663909","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}
引用次数: 0
Estudo Térmico, Caracterização Espectroscópica e Difração de Raio X do Cocristal de Ácido Salicílico com Ácido Nicotínico Obtido por Síntese Mecanoquímica 机械化学合成水杨酸与烟酸共晶的热研究、光谱表征和X射线衍射
Brazilian Journal of Thermal Analysis Pub Date : 2017-03-01 DOI: 10.18362/BJTA.V6I1.7
Laura Teófilo Ferreira, B. Holanda, Rafael Turra Alarcon, Gilbert Bannach
{"title":"Estudo Térmico, Caracterização Espectroscópica e Difração de Raio X do Cocristal de Ácido Salicílico com Ácido Nicotínico Obtido por Síntese Mecanoquímica","authors":"Laura Teófilo Ferreira, B. Holanda, Rafael Turra Alarcon, Gilbert Bannach","doi":"10.18362/BJTA.V6I1.7","DOIUrl":"https://doi.org/10.18362/BJTA.V6I1.7","url":null,"abstract":"","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86658127","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}
引用次数: 1
Synthesis, Thermal Behaviour and Catalytic Study of Ni-Chitosan in Transesterification Reaction Using Soybean Oil 大豆油酯交换反应中ni -壳聚糖的合成、热行为及催化研究
Brazilian Journal of Thermal Analysis Pub Date : 2017-03-01 DOI: 10.18362/BJTA.V6I1.6
C. Gaglieri, F. Caires, D. Silva, R. Bertholdo, R. Mendes
{"title":"Synthesis, Thermal Behaviour and Catalytic Study of Ni-Chitosan in Transesterification Reaction Using Soybean Oil","authors":"C. Gaglieri, F. Caires, D. Silva, R. Bertholdo, R. Mendes","doi":"10.18362/BJTA.V6I1.6","DOIUrl":"https://doi.org/10.18362/BJTA.V6I1.6","url":null,"abstract":"The biodiesel emerged as a substitute of standard diesel and could be considered a renewable and clean energy source. The transesterification reaction is considered the critical step in biodiesel production. The reaction between a short chain alcohol and chain triglycerides occurs in presence of a catalyst, which could be homogeneous or heterogeneous at reaction system. Trying solving the problems presented by homogeneous catalysis and finds viable applications conditions with heterogeneous catalysts, this work aimed to prepare and characterize a heterogeneous catalyst by chitosan with nickel (metallic complex) and then applies it in biodiesel production in laboratory scale. Simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC) and Fourier Transform Infrared Spectroscopy (FTIR) to characterize the catalyst. To characterize the biodiesel were used Fourier Transform Infrared Spectroscopy and measurements of viscosity and density. Keywords","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88490977","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}
引用次数: 1
Determinação da Energia de Ativação e Pureza de Formulações Farmacêuticas Contendo Paracetamol Utilizando Técnicas Termoanalíticas 用热分析技术测定含扑热息痛制剂的活化能和纯度
Brazilian Journal of Thermal Analysis Pub Date : 2017-03-01 DOI: 10.18362/bjta.v6i1.9
S. A. F. Paula, Érica Souza Oliveira, C. A. Júnior, Nedja Suely Fernandes
{"title":"Determinação da Energia de Ativação e Pureza de Formulações Farmacêuticas Contendo Paracetamol Utilizando Técnicas Termoanalíticas","authors":"S. A. F. Paula, Érica Souza Oliveira, C. A. Júnior, Nedja Suely Fernandes","doi":"10.18362/bjta.v6i1.9","DOIUrl":"https://doi.org/10.18362/bjta.v6i1.9","url":null,"abstract":"Paracetamol ( acetaminophen , N -acetyl- p- aminophenol ) is an antipyretic analgesic that has anti -inflammatory effect and is widely used in Brazil . This work was made use of Thermogravimetry ( TG ) and differential scanning calorimetry ( DSC ) to determine the activation energy and purity of pharmaceutical commercial forms of reference, generic and similar containing the active principle paracetamol . The Ozawa method was applied for the activation energy using thermogravimetric curves in three heating rates ( 5 , 10 and 20 ° C min - 1 ) . The results showed an average activation energy for the thermal decomposition evaluated between 87.2 and 103.7 kJ mol -1 . The Van't Hoff equation applied to the paracetamol fusion event observed in the DSC curves showed 99.5 , 99.3 and 99.6 % purity for the reference samples , and like generic , respectively.","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"138 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79851144","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}
引用次数: 0
Preparação, Caracterização e Avaliação do Potencial Antioxidadnte de Compostos L-Triptofano com Mn (II), Ni (II), Cu (II) e Zn (II) 含Mn (II)、Ni (II)、Cu (II)和Zn (II)的L-色氨酸化合物的制备、表征和抗氧化潜力评价
Brazilian Journal of Thermal Analysis Pub Date : 2016-10-01 DOI: 10.18362/BJTA.V5I1.2
Genilza da Silva Mello, A. Carvalho, A. Cardoso, A. B. Siqueira
{"title":"Preparação, Caracterização e Avaliação do Potencial Antioxidadnte de Compostos L-Triptofano com Mn (II), Ni (II), Cu (II) e Zn (II)","authors":"Genilza da Silva Mello, A. Carvalho, A. Cardoso, A. B. Siqueira","doi":"10.18362/BJTA.V5I1.2","DOIUrl":"https://doi.org/10.18362/BJTA.V5I1.2","url":null,"abstract":"L-Tryptophan (trp) is classified as an essential amino acid with an indolic side chain. Trp is an interesting ligand for the coordination chemistry due to different binding sites presented by the biomolecule and also low toxicity and high purity (above 99% w/w). Compounds with trp and metal ion (Mn2+, Ni2+, Cu2+ and Zn+2) were obtained in the solid state. The characterization was evaluated by simultaneous TGDSC, XRD and FTIR techniques. The DPPH’s reduction method was used to evaluate the antioxidant potential of the synthesized compounds. The thermoanalytical techniques could suggest the formation of compounds Mn(trp)2·1,5H2O, Ni(Trp)2·3,5H2O, Cu(Trp)2 and Zn(Trp)2. The IR spectra suggested M-N and M-O interaction to all compounds. The Mn(Trp)2·1,5H2O compound showed better antioxidant activity with the DPPH (24.59% ± 0.26) at the concentration of 250μM. The analysis of antioxidant activity has been used in research centers as the initial parameter for future applications in the pharmaceutical and food industry.","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"11 1","pages":"8-15"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84093030","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}
引用次数: 1
Thermoanalytical evaluation of essential oils of the leaves from Eucalyptus spp susceptible and resistant to Glycaspis brimblecombei. 易感和抗性桉树叶片精油的热分析评价。
Brazilian Journal of Thermal Analysis Pub Date : 2016-10-01 DOI: 10.18362/BJTA.V5.I1.1
G. L. D. A. D. Siqueira, M. Lazzarotto, M. S. Fernandes, A. C. D. Silveira, S. R. D. S. Lazzarotto, M. A. Filho, L. G. Lacerda, D. Queiroz, O. Miguel
{"title":"Thermoanalytical evaluation of essential oils of the leaves from Eucalyptus spp susceptible and resistant to Glycaspis brimblecombei.","authors":"G. L. D. A. D. Siqueira, M. Lazzarotto, M. S. Fernandes, A. C. D. Silveira, S. R. D. S. Lazzarotto, M. A. Filho, L. G. Lacerda, D. Queiroz, O. Miguel","doi":"10.18362/BJTA.V5.I1.1","DOIUrl":"https://doi.org/10.18362/BJTA.V5.I1.1","url":null,"abstract":"Euacalyptus is part of the national economy. This is a natural source that provides pulp for papermaking, coal for the steel industry and bioactive compounds used in various medical and industrial areas. The essential oil extracted from leaves is an important product obtained from Eucalyptus. This work evaluated essential oil extracted from leaves of Eucalyptus resistant and susceptible to Glycaspis brimblecombei using thermal tools. Samples of essential oils were extracted from crushed leaves of E. pellita (resistant) and E. camaldulenses (susceptible) by Clevenger method. The oils were analyzed by physicochemical characterization, thermogravimetry and differential thermal simultaneous analysis (TGA-DTA) and differential scanning calorimetry (DSC). The TGA curves of the essential oil from E. camaldulensis and commercial showed similarity and show that the major constituent can be 1,8-cineole. However, the TGA curves of the E. pellita essential oil has different pattern. In DSC, changing the endothermic peak of the commercial oil indicates the presence of other components or additives. The results indicate that these Eucalyptus essential oils had different chemical composition and the 1,8- cineole can be the reason of resistance and susceptibility to G. brimblecombei attack. Further studies will be performed to characterize these samples.","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"43 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82207558","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}
引用次数: 5
Synthesis and thermal studies of new soybean and grape seed oil-based polymers: Clean and efficient pathway using green Chemistry principles 新型大豆和葡萄籽油基聚合物的合成和热研究:利用绿色化学原理的清洁高效途径
Brazilian Journal of Thermal Analysis Pub Date : 2016-10-01 DOI: 10.18362/BJTA.V5I1.3
M. V. D. Almeida, R. Alarcon, G. Bannach
{"title":"Synthesis and thermal studies of new soybean and grape seed oil-based polymers: Clean and efficient pathway using green Chemistry principles","authors":"M. V. D. Almeida, R. Alarcon, G. Bannach","doi":"10.18362/BJTA.V5I1.3","DOIUrl":"https://doi.org/10.18362/BJTA.V5I1.3","url":null,"abstract":"This paper describes the synthesis of polymers from glycerol and vegetable oils as soybean and grape seed, synthesized following the principles of Green Chemistry. Simultaneous Thermogravimetric Analysis – Differential Thermal Analysis (TG-DTA) and Differential Scanning Calorimetry (DSC) were employed to evaluate the thermal decomposition, thermal stability, oxidation, glass transition and crystallization processes. Hence it was possible to verify that they have glass transition near to room temperature. Therefore these polymers may be used such as chemical slow release agents triggered by temperature and thermal security tags.","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"281 1 1","pages":"16-20"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86173923","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}
引用次数: 3
Membranas de Borracha natural crua utilizados como suporte para partículas de Dióxido de Titânio: Síntese, Caracterização e Avaliação térmica por TG-DTG e DSC 天然橡胶膜作为二氧化钛颗粒的载体:TG-DTG和DSC的合成、表征和热评价
Brazilian Journal of Thermal Analysis Pub Date : 2016-10-01 DOI: 10.18362/BJTA.V5I1.5
Jusinei Meireles Stropa, Aline S. Herrero, S. Santos, A. A. Cavalheiro, Amilcar Machulek
{"title":"Membranas de Borracha natural crua utilizados como suporte para partículas de Dióxido de Titânio: Síntese, Caracterização e Avaliação térmica por TG-DTG e DSC","authors":"Jusinei Meireles Stropa, Aline S. Herrero, S. Santos, A. A. Cavalheiro, Amilcar Machulek","doi":"10.18362/BJTA.V5I1.5","DOIUrl":"https://doi.org/10.18362/BJTA.V5I1.5","url":null,"abstract":"","PeriodicalId":9282,"journal":{"name":"Brazilian Journal of Thermal Analysis","volume":"103 1","pages":"31-38"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74217947","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}
引用次数: 1
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