Phenolic resins are important components of the composite industry because of their excellent flame retardance and cost effectiveness. However, the common procedure for curing phenolic novolac resins uses hexamethylenetetramine (HMTA) and releases volatiles during the cure, which produce networks with numerous voids. This results in materials that lack the toughness necessary for structural applications. An alternative to curing with HMTA is to crosslink the pendant phenolic groups in the novolac resin with epoxy reagents. This reaction proceeds by nucleophilic addition without the release of any volatiles, thereby creating a void-free network. Flame retardance can be achieved by using an excess of the phenolic component. Network densities can also be controlled to maximize both toughness and stiffness by tailoring the stoichiometry of the reagents. Structure-property relationships of phenolic/epoxy networks have been investigated. Glass transitions decreased, and toughness increased, as the phenolic content in the network was increased. Both results could be correlated to the decrease in network densities along this series, which was investigated by measuring the rubbery moduli well above T_g. Fracture toughness of phenolic/epoxy networks measured by K_1c reached 1.03 MPa-m^1/2, compared with an epoxy control with K^1c = 0.62 MPa-m^1/2 and phenolic control with K_1c = 0.16 MPa-m^1/2. In addition, an increase in novolac content improves flame retardance rather dramatically. The peak heat release rate (PHRR) dropped from 1230 kW/m²⁺ for the epoxy control to 260 kW/m²⁺ for the phenolic/epoxy networks, which approached that of a phenolic resol (PHRR = 116 kW/m²⁺). Phenolic/epoxy composite flame retardance also showed significant improvement when compared to epoxy composites. Melt processability of phenolic/epoxy composites has been achieved through the use of latent nucleophilic initiators. Kinetics of the phenolic/epoxy cure reactions with latent initiators demonstrated that monomeric phosphine initiators yielded faster cure reactions as compared to polymeric initiators. These latent initiators allow composite melt processing, such as prepregging or pultrusion, without premature curing. In addition, cure cycles can be reduced from 4 hours to less than 30 minutes. Composites prepared using these latent initiators had toughness exceeding that of epoxy composites and fatigue limits significantly higher than those of vinyl ester composites. <i>Vita removed, June 10, 2013, per author's request. GMc</i> / Ph. D.

The intent of this research was to enhance our knowledge of aqueous phenolformaldehyde resin cure as it is affected by the elevated water vapor pressures that occur during hot-pressing of a wood-based composite. Microdielectric spectroscopy (DEA) was used to monitor the cure reaction, and thermomechanical analysis (TMA), swelling tests and scanning electron microscopy (SEM) techniques were used to characterize the final resin-network. Microdielectric results showed that as the water vapor pressure of the sy stem increases the time to gelation increases. It was also found that the injection of saturated water vapor sharply decreased the gelation time when compared to the other water vapor environmental conditions. In addition, it was found that the higher the water vapor pressure the lower the residual ion viscosity. Thermomechanical analysis and swelling test experiments showed that as the water vapor pressure increases the glass transition temperature and the cross-link density of the cured resin-network decreases. Considerable differences in the morphology of the network were found using SEM. Thus, it can be established that during the curing process under elevated water vapor pressures of a liquid phenol-formaldehyde adhesive some water is trapped into the resin network and it is acting as a plasticizer. A theoretical approach to model the cure kinetics of phenol-formaldehyde has been developed. The model is based on the occurrence of two simultaneous processes (condensation polymerization and evaporation of water) and on the concentration dependency of the activation energy of polymerization. / Ph. D.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2009. / Härtill 5 uppsatser.

No description available.

Master of Science / Food Science Institute-Animal Science & Industry / Daniel Y.C. Fung / Three experiments were conducted to study the antimicrobial effectiveness of persimmon puree and phenolic compounds commonly found in the persimmon and plum. The objectives in experiment 1 were to evaluate the antimicrobial effects of persimmon puree on BioballTM Listeria monocytogenes and Escherichia coli O157 in a liquid medium. Persimmon puree was added at 1, 3, 5, and 10% wt./vol concentrations to brain heart infusion broth and inoculated with BioballTM Listeria monoctogenes and BioballTM Escherichia coli 0157. Microbial growth was evaluated at 0, 24, 36 and 72 h. Results indicated that at 24 h, persimmon puree at all concentrations suppressed (P<0.05) growth of L. monocytogenes compared to the control. Suppressed (P<0.05) growth of L. monocytogenes continued through 36 and 72 h for all concentrations of persimmon puree tested. However, due to non-pathogenic background Gram-negative micoflora, inhibition of E. coli O157 could not be ascertained. The objectives of experiment 2 were to evaluate the antimicrobial effectiveness of selected phenolic compounds (benzoic acid, gallic acid, vanillic acid, chlorogenic acid, and quercetin on E. coli O157:H7, Salmonella Typhimurium, Bacillus cereus, Yersinia enterocolitica, L. monocytogenes, and Staphylococcus aureus. Quercetin, vanillic, and chlorogenic acids were effective against selected pathogens at varying levels, but not as potent as Benzoic or Gallic acid. Results indicated that benzoic acid had the most effect against E. coli O157:H7, S. Typhimurium and B. cereus at concentrations of 452.98, 239.63 and 518.79 µg/ml, respectively. Gallic acid was the most effective against Y. enterocolitica, L. monocytogenes, and S. aureus at concentrations of 11.01, 29.06 and 22.45 µg/ml, respectively. The objective of experiment 3 were to evaluate the antimicrobial effectiveness of persimmon puree at concentrations of 0, 3, 5 and 10% wt./wt on a five strain cocktail of L. monocytogenes in ground beef. There was no suppression of growth at any concentration at 0, 1, 3 or 5 d. However, there was an increase (P<0.05) on 5 d for concentrations 5 and 10% persimmon puree when compared to the control. These series of experiments suggest that benzoic and gallic acids may have potential to suppress microbial growth. Persimmon puree appears to be an effective antimicrobial agent against Gram-positive bacteria in a liquid medium. However, incorporation of persimmon puree into ground beef did not yield an antimicrobial effect. Therefore, more research needs to be conducted to validate the effectiveness of phenolic compounds and persimmon puree as antimicrobial agents in food substances.

Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The separation of apple, cocoa and green tea phenolic compounds by comprehensive 2-dimensional liquid chromatography (2-D-LC) has been studied. In the first dimension, phenolic compounds were separated according to polarity by hydrophilic interaction chromatography (HILIC) on a diol stationary phase with a mobile phase containing acetonitrile, methanol, acetic acid and water. Gradient reversed-phase (RP) LC using a C18 column with fluorescence detection was employed in the second dimension to separate compounds according to hydrophobicity. Compounds were identified using negative electrospray ionisation mass spectrometry (ESI-MS) coupled to both HILIC and RP separations. The coupling of HILIC and RP separations proved to be especially beneficial since this provided simultaneous information on both the polarity and hydrophobicity of phenolics. The low degree of correlation (r2 < 0.21) between the two LC modes afforded peak capacities in excess of 3000 for the off-line method. An on-line method was also developed utilizing a short, small particle-packed column to provide fast separation in the second dimension. A 1 mm i.d. column was used in the first dimension for the on-line system to reduce injection volumes onto the second dimension column. A significantly lower practical peak capacity was measured for the on-line system, due largely to the reduction in second dimension peak capacity. On the other hand, analysis could be performed in an automated fashion using the online system reducing the risk of sample alteration and guaranteeing better operation reliability and reproducibility. Especially the off-line comprehensive HILIC × RP-LC method developed demonstrated its utility in the analysis of various groups of phenolic compounds including proanthocyanidins, phenolic acids, flavonols and flavonol conjugates in a variety of natural products. / AFRIKAANSE OPSOMMING: Die skeiding van fenoliese komponente in appel, kakao en groen tee is deur middel van ‘comprehensive’ 2-dimensionele vloeistof chromatografie (2-D-LC) bestudeer. Hidrofiliese interaksie chromatografie (HILIC) is gebruik om die fenoliese komponente in die eerste dimensie te skei op grond van polariteit, deur gebruik te maak van ‘n diol stationêre fase en mobiele fase bestaande uit asetonitriel, metanol, asynsuur en water. ‘n Gradiënt omgekeerde fase (RP) LC analisie op ‘n C18 kolom met fluorosensie deteksie is in die tweede dimensie gebruik om fenole volgens hidrofobisiteit te skei. Negatiewe elektrosproei-ionisasie massa spektometrie (ESIMS) gekoppel aan HILIC en RP skeidings is gebruik vir identifikasie van fenole. Die koppeling van HILIC en RP skeidings veral voordelig deurdat dit gelyktydige informasie verskaf het oor die polariteit sowel as die hidrofobisiteit van die fenoliese komponente. Die lae graad van korrelasie (r2 < 0.21) tussen die twee LC metodes was verantwoordelik vir piek kapasiteite bo 3000 vir die af-lyn metode. ‘n Aanlyn metode was ontwikkel deur gebruik te maak van ‘n kort, klein partikel gepakte kolom om vinnige skeiding in die tweede dimensie te verseker. 1 mm i.d. kolom was gebruik in die eerste dimensie vir die aanlyn sisteem om die inspuit volume op die tweede dimensie kolom te verminder. Aansienlike laer praktiese piek kapasiteit was gemeet vir die aanlyn sisteem, grootliks toegeskryf aan die reduksie in die tweede dimensie piek kapasitiet. Aan die ander kant, analise kan geoutomatiseerd uitgevoer word deur gebruik te maak van die aanlyn sisteem, wat monster alterasie, beter betroubaarheid en reproduseerbaarhied verseker. Veral die ontwikkelde af-lyn ‘comprehensive’ HILIC × RP-LC metode toon demonstreerbare voordele vir die analiese van verskeie groepe fenoliese komponente, insluitende proantosianiede, fenoliese sure, flavonole en gekonjugeerde flavonole in ‘n verskeidenheid natuurlike produkte.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Phenolic chemistry is quite complex; natural phenolic compounds vary widely in terms of size and chemical properties. The high structural diversity within this family presents severe analytical challenges. High performance liquid chromatography (HPLC) is the preferred method for phenolic analysis; however, conventional HPLC methods offer limited separation power and often provide incomplete separation of the large number of components present in natural phenolic extracts. Multi-dimensional chromatographic techniques have proven much more effective in the analysis of complex samples. The current study explored the potential of comprehensive two-dimensional liquid chromatography (LC×LC) for the characterisation of phenolic compounds in complex natural products, with the emphasis on proanthocyanidins (PACs). Initial work focused on the evaluation of the state of the art in phenolic analysis, to allow information which was used in the development of optimal 1-D separations for use in LC×LC. The combination of hydrophilic interaction chromatography (HILIC) in the first dimension with reversedphase liquid chromatography (RP-LC) in the second dimension afforded an orthogonal and powerful separation system for phenolics, providing separation on the basis of hydrophilicity and hydrophobicity, respectively. A detailed and systematic procedure was therefore developed to allow the optimisation and evaluation of on-line, off-line and stop-flow HILIC×RP-LC methods. Results showed that all three approaches provide much better separation performance than conventional one-dimensional LC (1-D LC) techniques. On-line HILIC×RP-LC offers automation, shorter analysis times, better reproducibility and minimal sample exposure. The off-line and stopflow methods are characterised by much higher peak capacities, but relatively long analysis times. It was also demonstrated that stop-flow operation results in negligible additional band broadening for procyanidins (PCs), implying that this method is an attractive alternative to the off-line method as it offers automation and minimal sample handling. Experimental verification of the predictions based on fundamental principles confirmed the validity of the optimisation procedure for cocoa PCs. The hyphenation of on-line HILIC×RP-LC separation with fluorescence (FL) and mass spectrometry (MS) detection methods provided enhanced resolution in a practical analysis time with the added benefit of selective detection and greater certainty in compound identification. This strategy proved much more powerful, as demonstrated by the identification of the highly complex PACs in grape seeds based on chromatographic retention data in two dimensions and accurate mass information. It was further shown that on-line coupling of HILIC×RP-LC separation with an optimised radical scavenging assay provides an improved approach for screening of individual radical scavengers in complex phenolic fractions, as demonstrated for cocoa, grape seed and green tea extracts. / AFRIKAANSE OPSOMMING: Fenoliese chemie is baie kompleks; natuurlike fenoliese verbindings varieer in terme van beide grootte en chemiese eienskappe. Hierdie hoë strukturele diversiteit binne die familie bied daadwerklike analitiese uitdagings. Hoëverrigtingvloeistofchromatografie (HPLC) is die voorkeurmetode vir fenoliese analises, maar konvensionele HPLC metodes bied egter 'n beperkte skeidingsvermoë en verskaf dikwels onvolledige skeiding van die groot aantal komponente teenwoordig in natuurlike fenoliese ekstrakte. Multi-dimensionele chromatografiese tegnieke is bewys om baie meer effektief te wees met betrekking tot die ontleding van komplekse monsters. Hierdie studie ondersoek die potensiaal van omvattende twee-dimensionele vloeistof chromatografie (LC×LC) vir die karakterisering van fenoliese verbindings in komplekse natuurlike produkte, met die fokus op pro-antosianidiëne (PAC’s). Aanvanklike werk het gefokus op die evaluering van moderne tegnieke vir fenoliese analise – inligting wat in die ontwikkeling van optimale 1-D skeidings vir die toepasing in LC×LC gebruik is. Die kombinasie van hidrofiliese interaksie chromatografie (HILIC) in die eerste dimensie met omgekeerde-fase vloeistof chromatografie (RP-LC) in die tweede dimensie verleen 'n ortogonale en kragtige skeidingsisteem vir fenoliese komponente en verskaf skeiding op grond van onderskiedelik hidrofiliteit en hidrofobiteit. ‘n Gedetailleerde en sistematiese prosedure is dus ontwikkel om die optimisering en evaluering van aan-lyn, af-lyn en stop-vloei HILIC×RP-LC metodes uit te voer. Resultate het getoon dat al drie benaderings baie beter skeidingsvermoë bied as konvensionele een-dimensionele LC (1-D LC) tegnieke. Aan-lyn HILIC×RP-LC bied outomatisering, korter ontledingstyd, beter herhaalbaarheid en minimale monster blootstelling. Die af-lyn en stop-vloei metodes word gekenmerk deur 'n veel hoër piekkapasiteit, maar relatief lang ontledingstye. Daar is ook getoon dat die stop-vloei prosedure geringe bykomende bandverbreding vir prosianodiniëne (PC’s) tot gevolg het, wat beteken dat hierdie metode 'n aantreklike alternatief is vir die af-lyn metode aangesien dit outomatisering bied en minimale monster hantering behels. Eksperimentele verifiëring van die voorspellings gebaseer op fundamentele beginsels bevestig die geldigheid van die optimalisering proses vir kakao PCs. Die koppeling van aan-lyn HILIC×RP-LC skeiding met fluoressensie (FL) en massaspektrometrie (MS) deteksie verskaf verbeterde resolusie binne 'n praktiese ontledingstyd saam met die bykomende voordeel van selektiewe opsporing en groter sekerheid betreffende die verbindings se identifikasie. Hierdie strategie was baie meer kragtig, soos gedemonstreer deur die identifisering van die hoogs komplekse PAC’s in druiwepitte gebaseer op chromatografiese behoud van die integriteit van die data in twee dimensies tesame met akkurate massa inligting. Daar is verder getoon dat aanlyn koppeling van HILIC×RP-LC skeiding met 'n geoptimiseerde radikale vangers deteksie-metode 'n beter benadering bied om die gedrag van individuele radikale vangers in komplekse fenoliese fraksies te bestudeer, soos bewys is vir kakao, druiwepitte en groen-tee ekstrakte.

A areia de fundição aglomerada com a resina fenólica se transforma num resíduo perigoso após o seu uso na indústria metalúrgica. O fenol, o meta-cresol e orto-cresol foram os principais compostos encontrados na areia de fundição. O presente trabalho tem por objetivo estudar a capacidade de degradação bacteriana do fenol, do meta-cresol e do orto-cresol. Para tanto foi isolada uma cepa proveniente de um resíduo de extração de petróleo tendo sido identificada pelo MALDI-Biotyper como sendo do gênero Burkholderia . Foi realizado o processo de ativação e crescimento bacteriano em pH 6,5, 180 rpm, 28°C e meio de cultura com mínimo de nutrientes, tendo como fonte de carbono areia de fundição contaminada com a resina fenólica. Durante os ensaios foram estudados o crescimento da bactéria bem como a degradação dos compostos fenólicos citados neste texto. A quantificação do fenol, meta-cresol e orto-cresol livres foram determinadas pelo método de cromatografia líquida de alta performance (HPLC - High Performance Liquid Chromatography ). A taxa de degradação para as três substâncias foi de 100%. / The casting sand agglomerated with the phenolic resin becomes a hazardous waste after its use in the metallurgical industry. The main compounds found in sand are phenol and its derivatives ortho-cresol and meta-cresol. The present work aims to study the bacterial degradability of the phenolic compounds present in the foundry sand. A strain from na oil extraction residue was isolated and identified by MALDI-Biotyper as Burkholderia diffusa. It was carried out the process of bacterial activation and growth at pH 6.5, 180rpm of agitation, temperature of 28°C and culture médium with minimum nutrients, using phenolic sand as the only source of carbon. During the tests the growth of the bacterium as well as the degradation of the phenolic compounds were studied. Quantification of free phenol, meta-cresol and ortho-cresol was determined by the high performance liquid chromatography (HPLC) method. The degradation rate for the three substances was 100%.

O pequi caracteriza-se por possuir expressiva quantidade de compostos fenólicos, que por apresentarem propriedades antioxidantes estão associados com a prevenção da formação de radicais livres. Além de ser consumido in natura, é também comumente consumido na forma processada. No entanto, sabe-se que os antioxidantes presentes nos vegetais podem ser afetados pela forma de processamento e provocam alterações dos teores de fenólicos totais (FT) bem como da sua atividade antioxidante. Este trabalho objetivou avaliar o teor de FT e as propriedades antioxidantes da polpa do pequi processado e in natura. Foram obtidos os extratos alcoólicos (EALC) e aquosos (EAQ), a partir de amostras liofilizadas de diversas polpas de pequi processado (em conserva) e também do in natura, bem como as frações de ácidos fenólicos livres (AFL), ésteres solúveis de ácidos fenólicos (AFS) e ésteres insolúveis de ácidos fenólicos (AFI) de pequi processado (CB1). Os EALC e EAQ, além dos líquidos provenientes das conservas (LC), foram avaliados quanto aos teores de FT, onde se verificou que os EAQ do pequi in natura, principalmente, e do processado tiveram um maior conteúdo de FT quando comparados aos EALC. Os LC, por sua vez, apresentaram valores médios ainda maiores que os EAQ. Com relação ao teor de FT das frações, a AFL se destacou diante da AFS e AFI. Os extratos, LC e frações foram avaliados quanto à atividade antioxidante in vitro pelo sistema &#946;-caroteno/ácido linoléico e também pelo ensaio do radical DPPH&#8226; (2,2 difenil-1-picril-hidrazila). No primeiro, verificou-se que os EAQ e LC do pequi apresentaram maior atividade que os EALC. Foi observada ainda atividade elevada em todas as frações analisadas. No segundo ensaio pelo método do radical DPPH&#8226;, pode-se observar que os extratos aquosos do pequi in natura apresentaram maior atividade, enquanto que, no pequi processado, os extratos alcoólicos e os líquidos das conservas tiveram melhores resultados. Verificou-se também que a AFL possui atividade superior às outras frações. De uma maneira geral, os resultados do pequi processado foram inferiores aos do pequi in natura tanto em relação aos teores de FT como na atividade antioxidante. Verificando-se ainda, que isto se deve principalmente à perda dos FT da polpa, indicando que houve lixiviação destes compostos para os LC. / Pequi characterized by having a significant amount of phenolic compounds, that are related with its antioxidant properties that are associated with the prevention of free radicals. Besides being eaten fresh, it is also widely consumed in processed form. However, it is known that the antioxidants present in plants can be affected by processing form and cause changes in the levels of total phenolic content (FT) and the antioxidant activity. The objective of this study was to evaluate the content of phenolic compounds and the antioxidant properties of the pequi pulp processed and fresh. Were obtained the alcoholic (EALC) and aqueous (EAQ) extracts from lyophilized samples of various pulps pequi processed (canned) and also in nature, as well as the fractions of free phenolic acids (AFL), soluble esters of phenolic acids (AFS) and insoluble esters of phenolic acids (AFI) of processed pequi (CB1). The EALC and EAq, besides the liquid from the canned (LC) were evaluated for the levels of FT, where it was found that the EAQ of the pequi in nature, mainly, and of the processed had, in general, a higher content of FT compared to EALC. The LC, in turn have showed that even greater EAQ. Regarding the content of FT of the fractions, the AFL stood in front of the AFS and AFI. The extracts, LC and fractions were also evaluated for their antioxidant activity in vitro by the system &#946;-caroteno/ linoleic acid and by test DPPH&#8226; (2,2-diphenyl-1-picryl hydrazyl). At first, it was found that the LC and EAQ of the pequi showed greater activity than the EALC. Still high activity was observed in all fractions analyzed. In the second test, we can observe that the EAQ of the pequi in nature showed greater activity, whereas in pequi processed, the EALC and LC had better results. It was also noted that the AFL has superior activity to other fractions. In general, the results of pequi processed were lower than in fresh pequi both in relation to content of FT as antioxidant activity. Verifying also, that this is mainly due to the loss of FT of the pulp, indicating that there was leaching of these compounds to the LC.

Ao contrário de muitos polímeros, as resinas fenólicas se caracterizam por possuir um grande número de aplicações por conta de sua superior resistência ao fogo e baixa emissão de fumos e ao seu excelente nível de resistência térmica e química, além de seu baixo custo. No entanto, devido à sua estrutura tridimensional, caracterizada pelo alto grau de reticulação, este tipo de resina apresenta baixas tenacidade e resistência à fratura. Com isso, para garantir seu bom desempenho, faz-se necessário promover modificações em sua formulação ou acrescentar agentes de reforço de modo a compensar essas deficiências resultantes de sua estrutura. São inúmeros os materiais que, usualmente, são incorporados à matriz fenólica. Além da preparação de blendas poliméricas em que uma das fases consiste em um elastômero ou um termoplástico, a introdução de agentes de reforço como materiais fibrosos também são utilizados. São exemplos de agentes de reforço: fibras vegetais, fibras de vidro e de carbono, negro de fumo, argilas entre outros. A mistura de polímeros e argilas pode levar à formação de nanocompósitos de modo a obter excelentes combinações de resistência à fratura, tenacidade, condutividade, resistência ao calor e redução da permeabilidade a gases e líquidos quando comparados com o polímero puro. Neste trabalho, argilas do tipo montmorilonita modificadas foram utilizadas como agente de reforço na preparação de filmes de nanocompósitos de matriz fenólica com o objetivo de melhorar as propriedades mecânicas deste material polimérico quando comparado com o material puro. A resina fenólica utilizada neste trabalho é a do tipo resol, utilizada comercialmente para a formulação de vernizes para revestimento de embalagens metálicas. No estudo foram utilizadas três argilas comerciais: Cloisite® sódica (Na) e argilas Cloisite® modificadas com sais quaternários de alquilamônio, de códigos 15A e 30B, objetivando verificar qual apresentaria melhor compatibilidade com a matriz fenólica. Para a preparação de filmes poliméricos uniformes, isentos de defeitos como bolhas, foi feita, de forma preliminar, a seleção de um ciclo de cura apropriado. Como a formação de bolhas é intrínseco à cura da resina fenólica resol, a definição de um esquema de tratamento térmico de cura apropriado constituiu-se em etapa crítica no processo de preparação dos compósitos de resina fenólica/argila montmorilonita modificada. Os filmes curados isentos de defeitos foram caracterizados por difração de raios X, análise termomecânica dinâmica (DMA) e calorimetria exploratória diferencial (DSC). Os resultados das análises de DRX mostraram para os compósitos preparados com as argilas modificadas 15A e 30B manutenção e até mesmo redução do espaçamento basal da estrutura cristalina das argilas, indicando não ter ocorrido intercalação do polímero nessas argilas; enquanto que para a argila Cloisite® Na ocorreu aumento do espaçamento basal. Os resultados de DMA mostraram para a maioria das amostras aumento no módulo de armazenamento em baixa e alta temperatura. Por último, a análise de DSC mostrou redução na temperatura de transição vítrea nos compósitos preparados com as argilas modificadas 15A e 30B, e elevação na composição de 5% da argila Cloisite® Na. Os resultados indicam o potencial de reforço mecânico de resinas fenólicas com argilas lamelares do tipo montmorilonita sem a necessidade de modificação química. / Unlike most polymers, phenolic resins are characterized by having a large number of applications because of its superior fire resistance and low emission of smoke and its excellent level of thermal and chemical resistance, and low cost. However, due to its three dimensional structure, characterized by a high degree of crosslinking, this type of resin has low toughness and fracture resistance. Thus, to ensure their good performance, it is necessary to make enhancements in their formulation or adding strengthening agents so as to compensate for these deficiencies due to its structure. There are numerous materials that usually are incorporated into the phenolic matrix. Besides the preparation of polymer blends in which one phase consists of an elastomer or a thermoplastic, the introduction of agents such as fibrous reinforcement is also used. Examples of reinforcing agents: vegetable fibers, glass and carbon fibers, carbon black, clay and others. The mixture of polymer clays may cause the formation of nanocomposites in order to obtain excellent combination of fracture strength, toughness, conductivity, heat resistance and reduced permeability to gases and liquids when compared with the pure polymer. In this work, modified montmorillonite clays were used as a reinforcing agent in the preparation of nanocomposite films of phenolic matrix with the aim of improving the mechanical properties of polymer materials when compared with the pure material. The phenolic resin used in this work is that of the resol type, used commercially for the formulation of varnish for coating metal containers. The study used three types of commercial clay: Cloisite® sodium (Na) and Cloisite® clays modified with quaternary alkylammonium salts, codes 15A and 30B in order to verify which present better compatibility with the phenolic matrix. For the preparation of uniform polymeric films, free of defects such as bubbles, was preliminarily selected a suitable cure cycle. As the bubble formation is intrinsic to the cure of resol phenolic resin, the definition of a heat treatment scheme is a critical step in the process of preparing composites of phenolic resin/montmorillonite clay. The cured films free of defects were characterized by X-ray diffraction (DRX), dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The results of XRD analysis showed the composites prepared with the modified clays 15A and 30B maintained and even reduced the basal spacing within the clay crystal structure, indicating not having occurred polymer intercalation of the clay; for the Cloisite® Na clay DRX has shown increased basal spacing. DMA results showed for most of the samples increase in storage modulus at low and high temperatures. Finally, DSC analysis showed a reduction in glass transition temperature of the composites prepared with the modified clays 15A and 30B, and an increase in the composition of 5% in the Cloisite® Na clay. The results indicate the potential of enhancement of phenolic resins mechanical properties with layered clays of montmorillonite without chemical modification.