Materials Research

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13556

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2015 - 201912020 - 20211

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Tem arquivos: SimAssunto: search.filters.subject.Biopolymer

Resultados da Pesquisa

Agora exibindo 1 - 2 de 2
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    Kinetic study of a bacterial cellulose production by Komagataeibacter rhaeticus using coffee grounds and sugarcane molasses
    (ABM, ABC, ABPol, 2021) Souza, Karina Carvalho de; Trindade, Nicolas Mattos; Amorim, Júlia Didier Pedrosa de; Nascimento, Helenise Almeida do; Costa, Andréa Fernanda Santana; Henrique, Mariana Alves; Caetano, Viviane Fonseca; Sarubbo, Leonie Asfora; Vinhas, Glória Maria
    Biotechnology can be used to convert waste into valuable products. In this context, there is bacterial cellulose (BC), a natural biopolymer that can be transformed into several useful materials, but its production is limited due to the high cost of the culture media used for its industrialization. In this work, BC was produced from the bacteria Komagataeibacter rhaeticus, using coffee grounds, sugarcane molasses and ethanol. The experiments were carried out under static conditions. The products were collected every 48 h, with a total period of 240 h. The maximum BC production (11.08 g.L-1) was obtained in a culture medium supplemented with coffee powder, hydrolyzed cane molasses and the addition of 1% (v/v) ethanol. The results show that the use of different carbon sources of the evaluated by-products are viable alternatives in reducing costs in BC production.
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    Particles of coffee wastes as reinforcement in polyhydroxybutyrate (PHB) based composites
    (ABM, ABC, ABPol, 2015) Reis, Kelen Cristina; Pereira, Lucinéia; Melo, Isabel Cristina Nogueira Alves; Marconcini, José Manoel; Trugilho, Paulo Fernando; Tonoli, Gustavo Henrique Denzin
    The objective of the present study was to evaluate lignocellulosic particles from sub-products of the coffee industry (coffee parchment - CP and husk - CH) into polyhydroxybutyrate (PHB) as a promising reinforcing filler in the biocomposites. The effects of type (CP or CH) and content (neat, 10% and 20%) of coffee wastes on the thermal, mechanical, microstructural and physical properties of the ensuing composites were evaluated. Thermal stability of the composites was improved by the coffee residues at different contents, while degree of crystallinity was decreased with the inclusion of CP. The addition of 10% of CP has not influenced significantly the tensile strength (TS) and Izod strength (IS), in relation to the neat PHB. Tensile strength (TS), MOE and Izod strength (IS) of the composites have increased significantly with the inclusion of 20% of CP. The increase in the content of coffee waste particles increased the water absorption of the composites.