Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-26T17:55:25Z No. of bitstreams: 1 2015 - Tha?s Gl?ucia Bueno Moreira.pdf: 292298 bytes, checksum: 71bdc650d433efc1801de110172240e0 (MD5) / Made available in DSpace on 2016-10-26T17:55:25Z (GMT). No. of bitstreams: 1 2015 - Tha?s Gl?ucia Bueno Moreira.pdf: 292298 bytes, checksum: 71bdc650d433efc1801de110172240e0 (MD5) Previous issue date: 2015-08-13 / CAPES / This study aimed evaluating changes in the Tifton 85 (Cynodon spp) hay chemical composition under different urea doses and treatment periods. The study was carried out at the Forage and Pastures Sector, Animal Nutrition and Pastures Department, Animal Science Institute in Universidade Federal Rural do Rio de Janeiro, Serop?dica-RJ, Brazil between August and September 2013. Completely randomized design with a factorial arrangement of five (45% N) (0, 1, 2, 3 and 4% based on dry matter) commercial urea doses distributed in a split-plot at two periods (30 and 45 days) for the bags opening, with five replications each was employed. The ammoniated material was stored in (1 kg hay / bag) plastic bags, sealed and after opening, samples were collected for bromathological analysis. No dose effect, time and dose x time interaction for dry matter, ether extract, neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose, lignin, acid detergent insoluble nitrogen, mineral matter, total carbohydrates, B2 fractions and carbohydrates fraction (P> 0.05) were reported. The variables crude protein, neutral detergent insoluble nitrogen and non-fibrous carbohydrates were influenced by urea doses. The ammoniation of Tifton 85 hay with urea at 1; 2; 3: 4% doses on dry matter might promote increases in crude protein and non-fibrous carbohydrates. However, cell wall constituents of the forage might not be altered, as well. / Objetivou-se neste trabalho avaliar as altera??es na composi??o bromatol?gica do feno de Tifton 85 (Cynodon spp) submetido a diferentes doses de ureia e per?odos de tratamento. O trabalho foi conduzido no setor de Forragicultura e Pastagens do Departamento de Nutri??o Animal e Pastagens do Instituto de Zootecnia, da Universidade Federal Rural do Rio de Janeiro, no munic?pio de Serop?dica-RJ, entre os meses de agosto e setembro de 2013. O experimento foi conduzido segundo um delineamento experimental inteiramente casualizado, sendo os tratamentos constitu?dos por cinco doses de ureia pecu?ria (45% de N) (0; 1; 2; 3 e 4% com base da MS) distribu?dos em esquema de parcelas subdivididas, contendo dois per?odos (30 e 45 dias) para a abertura dos sacos, com cinco repeti??es cada. O material amonizado foi armazenado em sacos pl?sticos (1 kg feno/saco), lacrados e, ap?s a abertura, foram coletadas amostras para an?lises bromatol?gicas. N?o houve efeito de dose, tempo e intera??o dose x tempo para as vari?veis de mat?ria seca, extrato et?reo, fibra em detergente neutro, fibra em detergente ?cido, hemicelulose, celulose, lignina, nitrog?nio insol?vel em detergente ?cido, mat?ria mineral, carboidrato total, fra??es B2 e fra??o C de carboidratos (P>0,05). J? as vari?veis prote?na bruta, nitrog?nio insol?vel em detergente neutro e carboidrato n?o fibroso foram influenciados pelas doses de ureia. A amoniza??o de feno de tifton 85 com ureia nas doses 1; 2; 3 e 4% em base da MS promove incrementos nos teores de prote?na bruta e carboidrato n?o fibroso. Entretanto, n?o altera os constituintes da parede celular da forrageira.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-09T18:53:53Z No. of bitstreams: 1 2016 - Leonardo Fiusa de Morais.pdf: 1229717 bytes, checksum: 4c0be638ee0ef0a26e196c1343e1858b (MD5) / Made available in DSpace on 2017-02-09T18:53:53Z (GMT). No. of bitstreams: 1 2016 - Leonardo Fiusa de Morais.pdf: 1229717 bytes, checksum: 4c0be638ee0ef0a26e196c1343e1858b (MD5) Previous issue date: 2016-07-29 / CAPES / The aim of this study was to evaluate the effect of ammoniated with different doses of urea in two treatment periods, and 3 different sources of urease on the nutritional value of elephant grass harvested after flowering in two chapters. The first chapter assessed the nutrition value of hay application of 2, 4, 6 and 8% of urea in two treatment periods (30 and 45 days) and control (not hay ammoniated). The second chapter evaluated the legume soybean, pigeon peas and jack beans sedds as urease sources, with the addition of 1, 2, 3 and 4% in ammoniated hay with urea and the control treatment (ammoniated hay with 4% urea without urease sources). The Experimental design was completely randomized in organized in double factorial arrangement with additional treatment. Dry matter (DM), ash, ether extract (EE), neutral detergent fiber (NDF), neutral detergent fiber corrected for the ash and the protein (NDFap), acid detergent fiber (ADF), cellulose, lignin, total nitrogen (TN), acid detergent insoluble nitrogen (ADIN), neutral detergent insoluble nitrogen (NDIN), Non protein N (NPN), in vitro gas production(Parameters: Vf1, k1, Vf2, K2 e L) and Carbohydrates fractioning were analysed. In the first study, was applied urea different doses at treatment periods, there was a difference (p<0,05) between the control and combination of factorial treatments for DM, EE, NDF, ADF, lignina, cellulose, NDFap, A + B1 fraction, B2 fraction, C fraction, TN, NPN, ADIN, NDIN, k1, L, Vf2, k2. Linear effect from dose was observed to NDFap, ADIN and NDIN and increasing dose to A+B1 fraction, TN, NNP. A quadratic effect for to Vf2, with point absolute maximum of 5,2% urea, and effect treatment period to Vf2 e K2, with higher and lower Vf2 K2 for hay treated 45 days. There was interaction (p<0,01) between sources of urease and level for NDF, ADF and lignin. The addition of 3% soybean or jack bean as a source of urease, resulted in lower NDF, and were not statistically different (p> 0.05), while pork beans had the highest NDF. There was a difference (P<0,05) between the control and combination of factorial treatments for NDF, A + B1 fraction. There was no interaction (p> 0.05) between source application level of urease, but was no effect (p <0.01) of urease source for NPN and ADIN. There was interaction (p <0.05) between source application level of urease to Vf1, but there was no interaction (p> 0.05) for k1, L, Vf2 and k2. Ammoniation urea and adding urease sources is an efficient method for chemical treatment of the elephant grass hay harvested after flowering, mainly by increasing the solubility fiber, in addition to the increased supply of non-protein nitrogen to rumen microorganisms, which resulted in improvement in vitro gas production of the kinetic parameters. / Objetivou-se avaliar o efeito da amoniza??o com aplica??o de diferentes doses de ur?ia em dois per?odos tratamento, e 3 diferentes fontes de urease, sobre o valor nutritivo do feno de capim-elefante colhido ap?s o florescimento, em dois cap?tulos. O primeiro cap?tulo avaliou o valor nutritivo do feno com aplica??o de 2, 4, 6 e 8% de ureia com base na mat?ria seca, em dois per?odos de tratamento (30 e 45 dias) e o controle (feno n?o amonizado),e o segundo que avaliou o efeito da adi??o de gr?os mo?dos das leguminosas soja, feij?o guandu e feij?o de porco como fontes de urease, em niveis de 1, 2, 3 e 4% com base na mat?ria seca do feno amonizado com 4% de ureia, e o tratamento controle (feno amonizado com 4% de ureia sem adi??o de fonte de ur?ase). O Delineamento experimental foi inteiramente casualizado em esquema fatorial duplo com tratamento adicional com 4 repeti??es por tratamento para os dois estudos. Foram realizadas as an?lises de mat?ria seca (MS), cinzas, extrato et?reo (EE), fibra em detergente neutro (FDN), fibra em detergente neutro corrigido para cinzas e prote?nas (FDNcp), fibra em detergente acido (FDA), celulose, lignina, prote?na bruta (PB), nitrog?nio insol?vel no detergente ?cido (NIDA) e produ??o cumulativa de g?s in vitro (Par?metros: Vf1, k1, Vf2, K2 e L) e o fracionamento de carboidratos. No primeiro estudo, houve diferen?a entre controle e a combina??o de tratamentos fatoriais para MS, EE, FDN, FDA, Lignina, celulose, FDNcp, fra??o A + B1, fra??o B2, fra??o C, NT, NNP, NIDA, NIDN, K1, L, Vf2, K2, e efeito (p <0,05) linear decrescente de dose de ureia para FDNcp, NIDA e NIDN e crescente de dose para fra??o A+B1, NT, NNP, efeito quadr?tico crescente de dose de ureia para Vf2 com ponto m?ximo absoluto de 5,2% de ureia.houve efeito de per?odo de tratamento para Vf2 e K2, com maior Vf2 e menor K2 para o feno tratado durante 45 dias. Houve intera??o (p<0,01) entre fonte de ur?ase e n?vel de fonte de ur?ase para FDN, FDA e lignina, sendo que a adi??o de 3,0% de soja ou feij?o guandu como fonte de ur?ase, resultaram em menores valores de FDN. Houve diferen?a (P<0,05) entre o controle e a combina??o de tratamentos fatoriais para FDN e fra??o A + B1 , mas n?o houve diferen?a (p > 0,05) entre o controle e a combina??o de tratamentos fatoriais para mat?ria seca, cinzas e extrato et?reo, mas foi observado efeito (p < 0,01) de fonte de ur?ase para extrato et?reo. N?o houve intera??o (p>0,05) entre fonte de ur?ase de n?vel de aplica??o, mas houve efeito (p<0,01) de fonte de urease para NNP e NIDA. Houve intera??o (p<0,05) entre fonte de ur?ase de n?vel de aplica??o para Vf1, mas n?o houve intera??o (p>0,05) para k1, L, Vf2 e k2. A dose m?nima de 5,2% de ureia durante um per?odo de 45 dias, proporcionou melhoria valor nutricional do feno de capim elefante. A amoniza??o com ureia e adi??o de fontes de ur?ase ? um m?todo eficiente para tratamento qu?mico do feno de capim elefante colhido ap?s o florescimento, principalmente pelo aumento da solubilidade fibra, al?m da maior oferta de nitrog?nio n?o proteico aos microrganismos ruminais, que resultou em melhoria dos par?metros cin?ticos de produ??o de g?s in vitro.

Made available in DSpace on 2014-12-17T14:06:51Z (GMT). No. of bitstreams: 1 TharsiaCCC.pdf: 1127571 bytes, checksum: caf0ffeeb86abc73d08cddd51d5f1c0b (MD5) Previous issue date: 2009-03-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Natural nanoclays are of great interest particularly for the production of polymer-based nanocomposites. In this work, kaolinite clays from two natural deposits in the State of the Rio Grande do Norte and Paraiba were purified with thermal treatment and chemical treatments, and characterized. Front to the gotten data, had been proposals methodologies for elimination or reduction of coarse particle texts, oxide of iron and organic substance. These methodologies had consisted of the combination of operations with thermal treatments, carried through in electric oven, and acid chemical attacks with and hydrogen peroxide. The Analyzers Thermogravimetric was used to examine the thermal stability of the nanoclays. The analysis indicated weight losses at temperatures under 110 ?C and over the temperature range of 350 to 550 ?C. Based on the thermal analysis data, the samples were submitted to a thermal treatment at 500 ?C, for 8 h, to remove organic components. The X-ray diffraction patterns indicated that thermal treatment under 500 ?C affect the basic structure of kaolinite. The BET surface area measurements ranged from 32 to 38 m2/g for clay samples with thermal treatment and from 36 to 53 m2/g for chemically treated samples. Thus, although the thermal treatment increased the surface area, through the removal of organic components, the effect was not significant and chemical treatment is more efficient, not affect the basic structure of kaolinite, to improve particle dispersion. SEM analysis confirms that the clay is agglomerated forming micron-size particles / As nanoargilas naturais s?o de grande interesse tecnol?gico, particularmente para a obten??o de nanocomp?sitos com matriz polim?rica. Neste trabalho, foram estudadas duas argilas caulin?ticas provenientes de dep?sitos naturais localizados nos estados do Rio Grande do Norte e da Para?ba. Estas argilas foram caracterizadas f?sica e quimicamente. Frente aos dados obtidos, foram propostos metodologias para elimina??o ou redu??o dos teores de part?culas grosseiras, de ?xido de ferro e de mat?ria org?nica. Estas metodologias consistiram na combina??o de tratamentos t?rmicos, realizadas em forno el?trico, e ataques qu?micos com ?cidos e per?xido de hidrog?nio. Com a an?lise termogravim?trica verificou-se a estabilidade t?rmica das amostras, que indicou perdas de massa na temperatura de 110 ?C e numa faixa de temperatura de 350?C a 550?C. Baseado nesses dados, as amostras foram submetidas a um tratamento t?rmico de 500?C por 8 horas para a remo??o dos componentes org?nicos. Os difratogramas de raios-X indicaram que o tratamento t?rmico alterou a sua estrutura b?sica. As medidas da ?rea da superficial (BET) variaram de 32 a 38 m2/g para amostras da argila com tratamento t?rmico e 36 a 53 m2/g para amostras tratadas quimicamente. Verificouse que o tratamento t?rmico promove um aumento significativo na ?rea de superf?cie. No entanto, seu efeito ? superado pelos tratamentos qu?micos que, adicionalmente, preservam a estrutura b?sica da caulinita e melhoram a dispers?o de part?culas, conforme evidenciado por microscopia eletr?nica de varredura

Made available in DSpace on 2014-12-17T15:41:55Z (GMT). No. of bitstreams: 1 JessicaEAF_DISSERT.pdf: 2802549 bytes, checksum: f4835fb277277d60879f0b91ee07c465 (MD5) Previous issue date: 2011-02-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In this work, the plant species Copernicia prunifera (Miller) H. E. Moore (carnauba), naturally occurring which prevails in the northeast region of Brazil was the subject of studies aiming its use as external coating of pipelines used in petroleum industry. The part of the plant worked were the leaves, also called straw, which were coated with resinous material. For this purpose, it was necessary to evaluate the effectiveness of the use of acrylic resins in the straw carnauba coating. The properties of the untreated carnauba straw and chemically treated with sodium hydroxide, hexane and carbon tetrachloride were investigated by ATRFTIR, SEM and thermal analysis. The first two techniques showed that treatment with solvents has caused major changes in the straw surface, while the thermal analysis indicated that the sodium hydroxide caused variations in thermal stability of straw constituents. Water absorption measurements showed that treatments have accelerated the absorption process and the reduction of contact angle values for treated samples with solvents indicated higher hidrophilicity of straw. The tensile tests showed lower values of elastic modulus and tensile strength for treated samples. Furthermore, coatings using pure commercial resins A and B as well as the formulations with clay were applied in straw and they were examined once again through thermal analysis, water absorption measurements, contact angle and mechanical tests. To analyze the effect of heat ageing, samples were subjected to tensile tests again in order to assess its resistance. The results showed that the resins/clay formulations increased thermal stability of straw, they promoted a good impermeabilization and caused significant decrease in the values of elastic modulus and tensile strength. Evaluating the ageing effect on the mechanical properties, it has been showed good recovery to the coated straw with the formulations A 60 and A 80% in modulus and tensile strength values and elongation at break values have remained very close. It is thus concluded that the carnauba straw can be used as a coating of pipelines with significant cost savings, since there is no need for pretreatment for its use and shows itself as a viable biotechnology alternative, contributing to the quality of coatings material and environment preservation. / Neste trabalho, a esp?cie vegetal Copernicia prunifera (Miller) H. E. Moore (carna?ba), de ocorr?ncia natural predominante da regi?o Nordeste do Brasil, foi alvo de estudos objetivando sua utiliza??o como revestimento externo de dutos da ind?stria do petr?leo. A parte da planta trabalhada foram as folhas, tamb?m chamadas de palhas, que receberam um revestimento resinoso. Para tanto, foi necess?rio avaliar a efic?cia do uso de resinas acr?licas no revestimento da palha de carna?ba. As propriedades da palha n?o-tratada e tratada quimicamente com hidr?xido de s?dio, hexano e tetracloreto de carbono foram investigadas por FTIR-ATR, MEV e TG. As duas primeiras t?cnicas mostraram que os tratamentos com os solventes provocaram maiores modifica??es na superf?cie da palha, enquanto o estudo termogravim?trico indicou que o hidr?xido de s?dio causou varia??es na estabilidade t?rmica dos constituintes da palha. Medidas de absor??o de ?gua mostraram que os tratamentos aceleraram o processo de absor??o e a redu??o dos valores de ?ngulo de contato para as amostras tratadas com os solventes indicou aumento da hidrofilicidade das palhas. Os ensaios mec?nicos apresentaram menores valores de m?dulo el?stico e tens?o de ruptura para as amostras tratadas. Al?m disso, revestimentos com resinas comerciais puras A e B assim como composi??es com argila foram aplicados nas palhas e estas foram analisadas novamente atrav?s da termogravimetria, medidas de absor??o de ?gua, ?ngulo de contato e resist?ncia mec?nica. Para analisar o efeito do envelhecimento t?rmico realizado, as amostras foram submetidas mais uma vez aos ensaios mec?nicos, a fim de avaliar sua resist?ncia. Os resultados mostraram que as formula??es resinas/argila aumentaram a estabilidade t?rmica da palha, promoveram uma boa impermeabiliza??o e causaram significativa redu??o nos valores de m?dulo el?stico e tens?o de ruptura. Ao avaliar o efeito do envelhecimento nas propriedades mec?nicas, percebeu-se boa recupera??o nos valores de m?dulo e tens?o para a palha revestida com as formula??es A 60 e A 80%. J? os resultados de deforma??o mostraram que os valores permaneceram bem pr?ximos. Dessa forma, conclui-se que a palha de carna?ba pode vir a ser utilizada como revestimento de dutos com significante redu??o de custos, j? que n?o h? a necessidade de tratamento pr?vio para seu uso e mostra-se como uma alternativa biotecnol?gica vi?vel, contribuindo com a qualidade de material de revestimentos e a preserva??o do meio ambiente.

Made available in DSpace on 2014-12-17T15:41:56Z (GMT). No. of bitstreams: 1 JessicaSM_DISSERT.pdf: 2134980 bytes, checksum: d9d14af471d3325a59885975b6f26a37 (MD5) Previous issue date: 2012-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work a biodegradable composite using the carnauba straw s powder as reinforcement on chitosan matrix polymeric were manufactured. Firstly, were carried out the chemistry characterization of the carnauba straw s powder before and after treatments with NaOH and hexane. Goering and Van Soest method (1970), flotation test, moisture absorption, FTIR, TG/DTG, DSC and SEM have also being carried out. Composites were developed with variations in granulometry and in powder concentrations. They were characterized by TG/DTG, SEM and mechanicals properties. The results of chemical composition showed that the carnauba straw s powder is composed of 41% of cellulose; 28,9% of hemicellulose and 14% of lignin.The flotation test have indicated that the chemical treatment with NaOH decreased the powder s hidrophilicity.The thermal analysis showed increased of thermal stability of material after treatments. The results of FTIR and SEM revealed the removal of soluble materials from the powder (hemicelluloses and lignin), the material became rougher and clean. The composites obtained showed that the mechanicals properties of the composites were decreased in respect at chitosan films, and the composites with the powder at 150 Mesh showed less variation in the modulus values. The speed test of 10 mm/min showed the better reproducibility of the results and is in agreement to the standard ASTM D638. The SEM analysis of fracture showed the low adhesion between the fiber/matrix. The increase of volume of powder in the composite caused a decrease in values of stress and strain for the samples with untreated powder and treated with hexane. The composite with 50% of the powder s treated in NaOH didn t have significant variation in the values of stress and strain as compared with the composites with 10% of the powder, showing that the increase in the volume of fiber didn t affect the stress and strain of the composite. Thereby, it is concluded that the manufacture of polymeric composites of chitosan using carnauba straw s powder can be done, without need for pre-treatment of reinforcement, become the couple of carnauba straw s powder-chitosan a good alternative for biodegradable composites / Neste trabalho foi produzido um comp?sito biodegrad?vel utilizando o p? da palha de carna?ba como refor?o e quitosana como a matriz polim?rica. Inicialmente, foi realizada a caracteriza??o qu?mica do p? da palha de carna?ba antes e ap?s os tratamentos com NaOH e hexano. Os m?todos de an?lise utilizados foram a determina??o da composi??o qu?mica descrita por Goering e Van Soest (1970), ensaio de flota??o e absor??o de umidade, FTIR, TG/DTG, DSC e MEV. Os comp?sitos foram desenvolvidos com varia??es na granulometria e nas concentra??es do p? da palha de carna?ba. Estes foram caracterizados por TG/DTG, MEV e por suas propriedades mec?nicas. Os resultados da composi??o qu?mica mostraram que o p? da palha de carna?ba ? constitu?do de 41% de celulose; 28,9% de hemicelulose e 14% de lignina. Os ensaios de flota??o indicaram que o tratamento com NaOH diminuiu o comportamento hidrof?lico do p?. As an?lises t?rmicas indicaram aumento na estabilidade t?rmica do material ap?s os tratamentos. Os resultados do FTIR e MEV evidenciaram a remo??o de materiais sol?veis do p? (hemiceluloses e lignina), deixando o material mais rugoso e limpo. An?lise t?rmica dos comp?sitos mostrou que ambos, refor?o e matriz sofrem degrada??o t?rmica na mesma temperatura. A adi??o do p? da palha de carna?ba diminui as propriedades mec?nicas do comp?sito em rela??o ao filme de quitosana puro e, o comp?sito obtido com os p?s a 150 Mesh foi o que apresentou menor varia??o nos valores de m?dulo. A velocidade de ensaio de 10 mm/min apresentou melhor reprodutibilidade nos resultados e se encontra de acordo com a norma ASTM D638. As an?lises de fratura do MEV mostraram baixa ades?o entre a fibra e a matriz. O aumento do volume de p? no comp?sito polim?rico provocou a diminui??o dos valores de tens?o e deforma??o para as amostras com p? n?o-tratado e tratado com hexano. Os comp?sitos com os p?s a 50% tratado com NaOH n?o apresentaram varia??o significativa nos valores de tens?o e deforma??o em rela??o aos comp?sitos com o p? a 10 %, indicando que o aumento no volume de fibra n?o comprometeu os valores de tens?o e deforma??o do comp?sito. Desse modo, pode-se concluir que a fabrica??o de comp?sitos polim?ricos de quitosana utilizando o p? da palha de carna?ba pode ser feito, sem a necessidade de tratamento pr?vio do refor?o, tornando o par p? de palha de carna?ba-quitosana uma boa alternativa para materiais comp?sitos biodegrad?veis

Made available in DSpace on 2014-12-17T14:06:55Z (GMT). No. of bitstreams: 1 FranciscoJPF.pdf: 1681554 bytes, checksum: 4238148885bafd3e26a8d8ca7de20466 (MD5) Previous issue date: 2010-08-07 / Nowadays the environmental issues are increasingly highlighted since the future of humanity is dependent on the actions taken by man. Major efforts are being expended in pursuit of knowledge and alternatives to promote sustainable development without compromising the environment. In recent years there has been a marked growth in the development of reinforced composite fiber plants, as an alternative for economic and ecological effects, especially in the substitution of synthetic materials such as reinforcement material in composites. In this current study the chemical- physical or (thermophysics )characteristics of the babassu coconut fiber, derived from the epicarp of the fruit (Orbignyda Phalerata), which the main constituents of the fiber: Klason lignin, insoluble, cellulose, holocellulose, hemicellulose and the content of ash and moisture will be determined. A study was conducted about the superficial modification of the fibers of the epicarp babassu coconut under the influence of chemical treatment by alkalinization, in an aqueous solution of NaOH to 2.5% (m/v) and to 5.0% to improve the compatibility matrix / reinforcement composite with epoxy matrix. The results of the changes occurred in staple fibers through the use of the techniques of thermogravimetric analyses (TG) and differential scanning calorimetry (DSC). The results found on thermal analysis on samples of fiber without chemical treatment (alkalinities), and on fiber samples treated by alkalinization show that the proposed chemical treatment increases the thermal stability of the fibers and provides a growth of the surface of area fibers, parameters that enhance adhesion fiber / composite. The findings were evaluated and compared with published results from other vegetable fibers, showing that the use of babassu coconut fibers has technical and economic potential for its use as reinforcement in composites / Atualmente as quest?es ambientais ganham destaque cada vez mais acentuado, j? que o futuro da humanidade est? dependente das a??es tomadas hoje pelo homem. Grandes esfor?os est?o sendo despendidos na busca de conhecimentos e solu??es alternativas sustent?veis que promova o desenvolvimento sem comprometimento do meio ambiente. Nos ?ltimos anos tem havido um crescimento acentuado no desenvolvimento de comp?sitos refor?ados por fibras vegetais, como uma alternativa econ?mica e ecol?gica, principalmente, na substitui??o de materiais sint?ticos, como material de refor?o em comp?sitos. No presente trabalho foram analisadas as caracter?sticas qu?mico-f?sicas de fibra oriundas do epicarpo do coco baba?u (Orbignyda Phalerata), sendo determinados os principais teores dos constituintes da fibra: lignina Klason insol?vel, celulose, holocelulose, hemicelulose e os teores de cinzas e de umidade. Foi realizado um estudo da modifica??o superficial das fibras do epicarpo do coco baba?u sob efeito de tratamento qu?mico por alcaliniza??o, em solu??o aquosa de NaOH a 2,5% (m/v) e a 5,0% (m/v), visando melhorar a compatibiliza??o matriz/refor?o em comp?sito com a matriz de ep?xi. Os resultados das modifica??es ocorridas nas fibras foram estudados atrav?s de t?cnicas de termogravimetria (TG) e de calorimetria explorat?ria diferencial (DSC). Os resultados encontrados nas an?lises t?rmicas em amostras de fibras sem tratamento qu?mico e em amostras de fibras tratadas por alcaliniza??o mostram que o tratamento qu?mico proposto aumentou a estabilidade t?rmica das fibras e proporcionou um crescimento na ?rea superficial das fibras, par?metros que melhoram a ades?o fibra/comp?sito. Os resultados obtidos foram avaliados e comparados com resultados publicados de outras fibras vegetais, mostrando que a utiliza??o das fibras de coco baba?u tem potencialidades t?cnicas e econ?micas para o seu uso como refor?o de comp?sitos