Made available in DSpace on 2014-12-17T14:57:53Z (GMT). No. of bitstreams: 1
SaniaMBA_TESE.pdf: 2511848 bytes, checksum: 97413b8278096d3ff64cc7f5138841e7 (MD5)
Previous issue date: 2012-04-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Chitin and chitosan are nontoxic, biodegradable and biocompatible polymers produced by
renewable natural sources with applications in diverse areas such as: agriculture, textile,
pharmaceutical, cosmetics and biomaterials, such as gels, films and other polymeric
membranes. Both have attracted greater interest of scientists and researchers as functional
polymeric materials. In this context, the objective of this study was to take advantage of the
waste of shrimp (Litopenaeus vannamei and Aristeus antennatus) and crabs (Ucides cordatus)
from fairs, beach huts and restaurant in Natal/RN for the extraction of chitin and chitosan for
the production of membranes by electrospinning process. The extraction was made through
demineralization, deproteinization, deodorization and deacetylation. Morphological analyzes
(SEM and XRD), Thermal analysis (TG and DTG), Spectroscopy in the Region of the
Infrared with Transformed of Fourier (FTIR) analysis Calorimetry Differential Scanning
(DSC) and mechanical tests for traction were performed. In (XRD) the semicrystalline
structure of chitosan can be verified while the chitin had higher crystallinity. In the thermal
analysis showed a dehydration process followed by decomposition, with similar behavior of
carbonized material. Chitosan showed temperature of maximum degradation lower than chitin.
In the analysis by Differential Scanning Calorimetry (DSC) the curves were coherent to the
thermal events of the chitosan membranes. The results obtained with (DD) for chitosan
extracted from Litopenaeus vannamei and Aristeus antennatus shrimp were (80.36 and
71.00%) and Ucides cordatus crabs was 74.65%. It can be observed that, with 70:30 solutions
(v/v) (TFA/DCM), 60 and 90% CH3COOH, occurred better facilitate the formation of
membranes, while 100:00 (v/v) (TFA/DCM) had formation of agglomerates. In relation to the
monofilaments diameters of the chitosan membranes, it was noted that the capillary-collector
distance of 10 cm and tensions of 25 and 30 kV contributed to the reduction of the diameters
of membranes. It was found that the Young s modulus decreases with increasing
concentration of chitosan in the membranes. 90% CH3COOH contributed to the increase in
the deformation resulting in more flexible material. The membranes with 5% chitosan 70:30
(v/v) (TFA/DCM) had higher tensile strength / Quitina e quitosana s?o pol?meros at?xicos, biodegrad?veis e biocompat?veis produzidos por
fontes naturais renov?veis com aplica??es em diversas ?reas como: agricultura, t?xtil,
farmac?utica, cosm?ticos e biomateriais, tais como g?is, filmes, membranas polim?ricas entre
outros. Ambas t?m despertando grande interesse de cientistas e pesquisadores como materiais
polim?ricos funcionais. Nesse contexto, o objetivo do presente trabalho foi aproveitar os
res?duos de camar?es (Litopenaeus vannamei e Aristeus antennatus) e de caranguejos (Ucides
cordatus) proveniente de feiras, barracas de praia e restaurantes em Natal/RN para extra??o
de quitina, quitosana e produ??o de membranas pelo processo de eletrofia??o. A extra??o foi
realizada a partir das etapas de desmineraliza??o, desproteiniza??o, desodoriza??o e
desacetila??o. An?lises morfol?gicas (MEV e DRX), an?lises das propriedades t?rmicas (TG
e DTG), an?lise por Espectroscopia na Regi?o do Infravermelho com Transformada de
Fourier (FTIR), an?lise de Calorimetria Explorat?ria Diferencial (DSC) e ensaios mec?nicos
por tra??o foram realizados. Na an?lise de DRX pode-se verificar a estrutura semicristalina da
quitosana enquanto a quitina teve alta cristalinidade. As an?lises t?rmicas demonstraram um
processo de desidrata??o seguido da decomposi??o com comportamento similar de material
carbonizado. A quitosana apresentou temperaturas de m?xima degrada??o mais baixas do que
a quitina. Na an?lise por Calorimetria Explorat?ria Diferencial (DSC) as curvas foram
coerentes aos eventos t?rmicos das membranas de quitosana. Os resultados obtidos com (GD)
para quitosana extra?da de camar?es Litopenaeus vannamei e Aristeus antennatus foram
(80,36 e 71,00%) e caranguejos Ucides cordatus foi 74,65%. Pode-se perceber que, com
solu??es 70:30 (v/v) (TFA/DCM), 60 e 90% CH3COOH, ocorreu melhor facilita??o na
forma??o das membranas, enquanto em 100:00 (v/v) (TFA/DCM) houve forma??o de
aglomerados. Em rela??o aos di?metros dos nanofilamentos das membranas de quitosana,
percebeu-se que a dist?ncia capilar-coletor de 10 cm e tens?es de 25 e 30 kV contribu?ram
para a redu??o dos di?metros das membranas. Quanto ao m?dulo de Young diminui com o
aumento da concentra??o da quitosana nas membranas. 90% CH3COOH contribuiu para o
aumento da deforma??o, sendo um material mais flex?vel. As membranas com 5% quitosana
70:30 (v/v) (TFA/DCM) apresentaram maior valor de resist?ncia ? tra??o
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/15590 |
| Date | 13 April 2012 |
| Creators | Andrade, S?nia Maria Bel?sio de |
| Contributors | CPF:18222161415, http://lattes.cnpq.br/8553209522282182, Mendes, Jos? Ubiragi de Lima, CPF:13291085400, http://lattes.cnpq.br/7103009428184656, Felipe, Maria Gorete, CPF:19989490449, http://lattes.cnpq.br/3151683042790067, Lima, Jos? de Anchieta, CPF:36973637434, http://lattes.cnpq.br/0742445504420593, Souza, Roberto Silva de, CPF:44466927472, http://lattes.cnpq.br/4012782800846844, Ladchumananandasivam, Rasiah |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Engenharia Mec?nica, UFRN, BR, Tecnologia de Materiais; Projetos Mec?nicos; Termoci?ncias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0024 seconds