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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Colagem de pain?is OSB com adesivos ? base de taninos da casca de Pinus oocarpa Schiede ex Schltdl. / Bonding of OSB with tannins adhesives from the bark of Pinus oocarpa Schiede ex Schltdl.

Vieira, Michel Cardoso 12 March 2010 (has links)
Made available in DSpace on 2016-04-28T14:56:20Z (GMT). No. of bitstreams: 1 Michel Cardoso.pdf: 285596 bytes, checksum: e021aeca652bc3b1ad648b8db8f92e3c (MD5) Previous issue date: 2010-03-12 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This work aimed to study the feasibility of using tannins from the bark of Pinus oocarpa as tannin-formaldehyde adhesive to produce OSB. For the pine-bark oocarpa were tested eight forms of extraction of tannins. After evaluation of the chemical properties of tannic extracts was decided to employ the extraction with distilled water / 5% sodium sulfite to prepare for the tannin-formaldehyde adhesive. Adhesive phenol formaldehyde and urea-formaldehyde were modified with 10% tannin Pinus oocarpa and the effect of this addition on the quality of the adhesive was evaluated. OSB panels were manufactured with tannin adhesives from Pinus oocarpa (TF), Urea-Formaldehyde (UF), Phenol-Formaldehyde (PF) of UF modified with tannin and pine tannin FF modified with pine, using two times pressing . The analysis were based on the tests of static bending, tensile strength perpendicular to surface, thickness swelling and water absorption. The average density of the panels was 0.47 g/cm3. The addition of tannic extract from the bark of Pinus oocarpa proved adequate for the manufacture of OSB having in view the results for the physical and mechanical properties. The results also showed that it is possible to manufacture panels with adhesive based on pure tannin of Pinus oocarpa, however, the panels showed low strength and low dimensional stability. / Esse trabalho teve por objetivo estudar a viabilidade de utiliza??o dos taninos da casca de Pinus oocarpa como adesivo para produ??o de pain?is OSB. Para a casca de Pinus oocarpa foram testadas oito formas de extra??o dos taninos. Ap?s a avalia??o das propriedades qu?micas dos extratos t?nicos optou-se por empregar a extra??o com ?gua destilada sob adi??o de 5 % de sulfito de s?dio para confec??o do adesivo tanino-formalde?do. Adesivo Fenol- Formalde?do e Ur?ia-Formalde?do foram modificados com 10% de tanino de Pinus oocarpa e o efeito desta adi??o sobre a qualidade do adesivo foi avaliado. Foram fabricados pain?is OSB com adesivos de tanino de Pinus oocarpa (TF), de Ur?ia-Formalde?do (UF), Fenol-Formalde?do (FF), de UF modificado com tanino de pinus e FF modificado com tanino de pinus, utilizando dois tempos de prensagem. Os pain?is foram avaliados quanto ? resist?ncia a flex?o est?tica (MOR e MOE), resist?ncia ? tra??o perpendicular, (liga??o interna-LI), densidade e estabilidade dimensional (inchamento em espessura IE e absor??o em ?gua AA). O valor m?dio da densidade dos pain?is foi de 0,47 g/cm3. A adi??o de extrato t?nico da casca de Pinus oocarpa mostrou-se adequada para a fabrica??o de pain?is OSB tendo-se em vista os resultados obtidos para as propriedades f?sico-mec?nicas. Os resultados mostraram tamb?m que ? poss?vel fabricar pain?is com adesivo puro ? base de tanino de Pinus oocarpa; entretanto, os pain?is apresentaram baixa resist?ncia mec?nica e baixa estabilidade dimensional.

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