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Previous issue date: 2014-08-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O aproveitamento sustent?vel de res?duos decorrente da agroind?stria ? atualmente
foco de pesquisas, com destaque para o baga?o de cana de a??car (BCA), por ser o
res?duo lignocelul?sico produzido em maior volume na agroind?stria brasileira, onde
a biomassa residual tem sido aplicada na produ??o de energia el?trica e
bioprodutos. Neste trabalho, foi produzida celulose com elevada pureza, a partir do
(BCA), por polpa??o soda/antraquinona e, posterior convers?o em acetato de
celulose. A celulose comercial Avicel foi utilizada para compara??o. A obten??o do
acetato de celulose ocorreu por rea??o de acetila??o homog?nea, modificando-se as
vari?veis, tempo reacional, em horas, (8, 12, 16, 20 e 24) e temperatura, em ?C, (25
e 50). Os espectros de FTIR indicaram bandas caracter?sticas id?nticas para os
materiais celul?sicos, o que demonstra a efici?ncia da separa??o por polpa??o. A
caracteriza??o da celulose e do acetato obtidos ocorreu por espectroscopia de
infravermelho (FTIR), difra??o de raios X (DRX), an?lises termogravim?tricas
(TG/DTG/DSC), microscopia eletr?nica de varredura (MEV) e determina??o do grau
de substitui??o (GS) para o acetato de celulose, para confirma??o da acetila??o. Os
tempos reacionais ?timos para a obten??o de diacetatos e triacetatos, em ambas as
temperaturas foram 20 h e 24 h. O acetato de celulose, produzido do BCA,
apresentou GS entre 2,57 e 2,7 na temperatura de 25?C e, a 50 ?C, os GS obtidos
foram 2,66 e 2,84, indicando real convers?o da celulose do BCA em di e triacetatos.
De modo comparativo, a celulose comercial Avicel apresentou GS de 2,78 e 2,76 a
25 ?C e 2,77 e 2,75 a 50 ?C. Os dados foram obtidos no tempo de 20 h e 24 h,
respectivamente. O melhor resultado ocorreu para a s?ntese do acetato de celulose
obtida do BCA, com GS de 2,84 a 50?C e 24 h, sendo classificado como triacetato
de celulose, que apresentou resultado superior ao acetato produzido com a celulose
comercial Avicel, demonstrando a potencialidade de convers?o da celulose obtida a
partir de um res?duo lignocelul?sicos (BCA), de baixo custo, com perspectivas de
utiliza??o comercial do acetato de celulose / The sustainable use of waste resulting from the agribusiness is currently the focus of
research, especially the sugar cane bagasse (BCA), being the lignocellulosic waste
produced in greater volume in the Brazilian agribusiness, where the residual biomass
has been applied in production energy and bioproducts. In this paper, pulp was
produced in high purity from the (BCA) by pulping soda / anthraquinone and
subsequent conversion to cellulose acetate. Commercial cellulose Avicel was used
for comparison. The obtained cellulose acetate was homogeneous acetylation
reaction by modifying the variables, the reaction time in hours (8, 12, 16, 20 and 24)
and temperature in ? C (25 and 50). FTIR spectra showed characteristic bands
identical to cellulosic materials, demonstrating the efficiency of separation by pulping.
The characterization of cellulose acetate was obtained and by infrared spectroscopy
(FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG / DTG / DSC),
scanning electron microscopy (SEM) and determining the degree of substitution (DS
) for the cellulose acetate to confirm the acetylation. The optimal reaction time for
obtaining diacetates and triacetates, at both temperatures were 20 and 24 h.
Cellulose acetate produced BCA presented GS between 2.57 and 2.7 at 25 ? C and
50 ? C GS obtained were 2.66 and 2.84, indicating the actual conversion of cellulose
BCA of di- and triacetates. Comparative mode, commercial cellulose Avicel GS
showed 2.78 and 2.76 at 25 ? C and 2.77 to 2.75 at 50 ? C. Data were collected in
time of 20 h and 24 h, respectively. The best result was for the synthesis of cellulose
acetate obtained from the BCA GS 2.84 to 50 ? C and 24 hours, being classified as
cellulose triacetate, which showed superior result to that produced with the
commercial ethyl cellulose Avicel, demonstrating converting potential of cellulose
derived from a lignocellulosic residue (BCA), low cost, prospects of commercial use
of cellulose acetate
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/19598 |
| Date | 15 August 2014 |
| Creators | Silva, Valdic Luiz da |
| Contributors | 27832155515, Silva, Ademir Oliveira da, 16225422404, http://lattes.cnpq.br/3511004608337461, Pontes, Luiz Ant?nio Magalh?es, 65440587772, http://lattes.cnpq.br/2865282329757428, Silva, Ademir Oliveira da, Santos, Luciene da Silva |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM QU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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