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Estudos de consolidação de azulejos cerâmicos
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A presente tese teve como objetivo o tratamento do corpo cerâmico de azulejos com
produtos protetores poliméricos. Estudaram-se as eventuais alterações introduzidas nas
propriedades pelos diferentes tratamentos de consolidação.O património azulejar português é vasto, visto o azulejo ser utilizado em Portugal desde oséc. 15, como é possível comprovar pelo acervo do Museu Nacional do Azulejo. Muitas
vezes, os painéis existentes nos mais variados edifícios, estão em condições precárias de
conservação, sendo de importância fulcral as intervenções de conservação e/ou restauro.
Os materiais protetores utilizados devem promover um bom revestimento dos azulejos. O
material mais usado nos departamentos de restauro dos museus é o consolidante acrílico
Paraloid B-72 numa concentração de 10% em acetona sendo feita um dupla impregnação
do corpo cerâmico. No entanto, é de todo o interesse encontrar uma alternativa mais “amiga
do ambiente” em que se reduza a quantidade de produtos orgânicos e que seja também
mais económica. Nesse sentido, neste trabalho utilizou-se vários produtos protetores,
nomeadamente outros produtos acrílicos para além do Paraloid B-72, como Elvacite E2046
e Elvacite 4067, alcoxisilanos, concretamente Tegovakon V 100 e Silres BS 290. Foi
também explorada a utilização de um polímero obtido pelo método sol-gel, (3-
-glicidiloxipropil)trimetoxisilano (GPTMS) hidrolisado e um híbrido derivado deste,
GPTMS/DETA.As amostras utilizadas foram agrupadas em três conjuntos. Os grupos B e C referem-
-se a azulejos antigos cedidos pelo Museu Nacional do Azulejo. Os azulejos do grupo A
foram fornecidos pela Fábrica de Sant’Anna, que mantém o processo de manufatura usado
no séc. 18. Como os azulejos antigos são raros, o estudo mais detalhado do efeito da
consolidação com vários produtos foi feito com as amostras do grupo A, disponíveis em
maior quantidade.Estudou-se o efeito da consolidação em diferentes parâmetros determinados pelos testes de
absorção de água por capilaridade, ensaios de flexão em quatro pontos, caracterização
estrutural por Microscopia Electrónica de Varrimento (MEV), medição da velocidade de
ultrassons, ensaios de resistência ao arrancamento por tração e permeabilidade ao vapor de
água. A porosidade é uma propriedade fundamental dos materiais cerâmicos, tendo sido
avaliada por vários métodos: adsorção de azoto, picnometria de hélio, MEV com análise de
imagem e absorção capilar de água.Os tratamentos de consolidação considerados mais adequados foram os obtidos com as
amostras designadas por PB72-1-30, PB72-5-30, TGV-180 TGVPB72-5-180, TGVPB72-10-
-180, GPTMS/DETA-10 e GPTMS/DETA-30. Com este estudo foi possível verificar que se
poderá fazer tratamentos do corpo cerâmico dos azulejos, tanto com Paraloid B-72, em
menor concentração em solução, menor tempo de impregnação, bem como com outros
produtos poliméricos.Deste modo, este estudo dá uma contribuição importante no sentido de a consolidação dos
azulejos poder ser um processo mais económico e com menor utilização de produtos
orgânicos.This thesis focuses on the treatment of the ceramic body of tiles with polymeric protective
products. Possible changes in the proprerties induced by the different consolidation
treatments were evaluated.The Portuguese tile heritage is vast, as tiles have been used in Portugal since the 15th
century, which is recognized in the collections of the Museu Nacional do Azulejo. A large
number of panels that exist in buildings are deteriorated, being the conservation and/or
protection interventions extremely important. The materials used to this purpose must
promote a good coating of the tiles. In the majority of the museum restoration departments,
the most used material is the acrylic consolidant Paraloid B-72 in 10% concentration in
acetone with double impregnation, of the ceramic body. However, it is important to find an
environmentally friendly alternative that reduces the amount of organic products and that can
also be more economic. In this sense, several protective products besides from Paraloid B-
-72, were studied, namely other acrylic products, such as Elvacite 2046 and Elvacite 4067,
alcoxisilanes, specifically Tegovakon V 100 and Silres BS 290. A polymer obtained by sol-gel
method, (3-glycidoxypropyl)methyldiethoxysilane (GPTMS) and a hybrid, synthesized in the
lab, GPTMS/DETA were also experienced.The ceramic tile samples were grouped in three sets. Groups B and C gathers ancient tiles supplied by the Museu Nacional do Azulejo. The group A tiles were provided by the Fábrica
de Sant’Anna, that still manufactures tiles according to a 18th century procedure. As ancient
tiles are rare, the larger study on the effect of the consolidation procedure with the several
products was conducted with the samples of group A which are available in larger quantity.
The effect of the consolidation in different parameters was studied throughout capillary water
absorption tests, four point bending tests, structural characterization by Scanning Electron
Microscopy (SEM), measurements of ultrasonic velocity, tensile adhesion strength tests and
water vapour permeability tests. The porosity is a fundamental propriety of ceramic materials
and was assessed by several methods: nitrogen adsorption, helium pycnometry, SEM with
image analysis and capillary water absorption.The consolidation treatments considered to be more appropriate were the ones attained in the samples PB72-1-30, PB72-5-30, TGV-180 TGVPB72-5-180, TGVPB72-10-180,
GPTMS/DETA-10 and GPTMS/DETA-30. During this work it was found that it is possible to
make treatments with Paraloid B-72 with lower concentration solutions, less impregnation
time, with only one impregnation, as well as, other polymeric products.
In this sense, this study is an important contribution towards a less expensive consolidation
procedure with a decrease of the amount of the organic products.
This thesis focuses on the treatment of the ceramic body of tiles with polymeric protective products. Possible changes in the proprerties induced by the different consolidation treatments were evaluated.The Portuguese tile heritage is vast, as tiles have been used in Portugal since the 15th century, which is recognized in the collections of the Museu Nacional do Azulejo. A large number of panels that exist in buildings are deteriorated, being the conservation and/or protection interventions extremely important. The materials used to this purpose must promote a good coating of the tiles. In the majority of the museum restoration departments, the most used material is the acrylic consolidant Paraloid B-72 in 10% concentration in acetone with double impregnation, of the ceramic body. However, it is important to find an environmentally friendly alternative that reduces the amount of organic products and that can also be more economic. In this sense, several protective products besides from Paraloid B- -72, were studied, namely other acrylic products, such as Elvacite 2046 and Elvacite 4067, alcoxisilanes, specifically Tegovakon V 100 and Silres BS 290. A polymer obtained by sol-gel method, (3-glycidoxypropyl)methyldiethoxysilane (GPTMS) and a hybrid, synthesized in the lab, GPTMS/DETA were also experienced.The ceramic tile samples were grouped in three sets. Groups B and C gathers ancient tiles supplied by the Museu Nacional do Azulejo. The group A tiles were provided by the Fábrica de Sant’Anna, that still manufactures tiles according to a 18th century procedure. As ancient tiles are rare, the larger study on the effect of the consolidation procedure with the several products was conducted with the samples of group A which are available in larger quantity. The effect of the consolidation in different parameters was studied throughout capillary water absorption tests, four point bending tests, structural characterization by Scanning Electron Microscopy (SEM), measurements of ultrasonic velocity, tensile adhesion strength tests and water vapour permeability tests. The porosity is a fundamental propriety of ceramic materials and was assessed by several methods: nitrogen adsorption, helium pycnometry, SEM with image analysis and capillary water absorption.The consolidation treatments considered to be more appropriate were the ones attained in the samples PB72-1-30, PB72-5-30, TGV-180 TGVPB72-5-180, TGVPB72-10-180, GPTMS/DETA-10 and GPTMS/DETA-30. During this work it was found that it is possible to make treatments with Paraloid B-72 with lower concentration solutions, less impregnation time, with only one impregnation, as well as, other polymeric products. In this sense, this study is an important contribution towards a less expensive consolidation procedure with a decrease of the amount of the organic products
This thesis focuses on the treatment of the ceramic body of tiles with polymeric protective products. Possible changes in the proprerties induced by the different consolidation treatments were evaluated.The Portuguese tile heritage is vast, as tiles have been used in Portugal since the 15th century, which is recognized in the collections of the Museu Nacional do Azulejo. A large number of panels that exist in buildings are deteriorated, being the conservation and/or protection interventions extremely important. The materials used to this purpose must promote a good coating of the tiles. In the majority of the museum restoration departments, the most used material is the acrylic consolidant Paraloid B-72 in 10% concentration in acetone with double impregnation, of the ceramic body. However, it is important to find an environmentally friendly alternative that reduces the amount of organic products and that can also be more economic. In this sense, several protective products besides from Paraloid B- -72, were studied, namely other acrylic products, such as Elvacite 2046 and Elvacite 4067, alcoxisilanes, specifically Tegovakon V 100 and Silres BS 290. A polymer obtained by sol-gel method, (3-glycidoxypropyl)methyldiethoxysilane (GPTMS) and a hybrid, synthesized in the lab, GPTMS/DETA were also experienced.The ceramic tile samples were grouped in three sets. Groups B and C gathers ancient tiles supplied by the Museu Nacional do Azulejo. The group A tiles were provided by the Fábrica de Sant’Anna, that still manufactures tiles according to a 18th century procedure. As ancient tiles are rare, the larger study on the effect of the consolidation procedure with the several products was conducted with the samples of group A which are available in larger quantity. The effect of the consolidation in different parameters was studied throughout capillary water absorption tests, four point bending tests, structural characterization by Scanning Electron Microscopy (SEM), measurements of ultrasonic velocity, tensile adhesion strength tests and water vapour permeability tests. The porosity is a fundamental propriety of ceramic materials and was assessed by several methods: nitrogen adsorption, helium pycnometry, SEM with image analysis and capillary water absorption.The consolidation treatments considered to be more appropriate were the ones attained in the samples PB72-1-30, PB72-5-30, TGV-180 TGVPB72-5-180, TGVPB72-10-180, GPTMS/DETA-10 and GPTMS/DETA-30. During this work it was found that it is possible to make treatments with Paraloid B-72 with lower concentration solutions, less impregnation time, with only one impregnation, as well as, other polymeric products. In this sense, this study is an important contribution towards a less expensive consolidation procedure with a decrease of the amount of the organic products
Descrição
Tese de doutoramento, Química (Química-Tecnológica), Universidade de Lisboa, Faculdade de Ciências, 2013
Palavras-chave
Azulejos Química tecnológica Teses de doutoramento - 2013