1 resultado para Function evaluation
em Repositório Institucional da Universidade Federal do Rio Grande - FURG
Filtro por publicador
- ABACUS. Repositorio de Producción Científica - Universidad Europea (1)
- Aberystwyth University Repository - Reino Unido (3)
- Academic Research Repository at Institute of Developing Economies (1)
- Acceda, el repositorio institucional de la Universidad de Las Palmas de Gran Canaria. España (1)
- AMS Tesi di Dottorato - Alm@DL - Università di Bologna (4)
- AMS Tesi di Laurea - Alm@DL - Università di Bologna (2)
- Aquatic Commons (3)
- ARCA - Repositório Institucional da FIOCRUZ (1)
- ArchiMeD - Elektronische Publikationen der Universität Mainz - Alemanha (3)
- Archive of European Integration (1)
- Aston University Research Archive (16)
- Biblioteca de Teses e Dissertações da USP (1)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (24)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP) (7)
- Bioline International (4)
- BORIS: Bern Open Repository and Information System - Berna - Suiça (33)
- Boston University Digital Common (1)
- Brock University, Canada (4)
- Bulgarian Digital Mathematics Library at IMI-BAS (1)
- CaltechTHESIS (3)
- Cambridge University Engineering Department Publications Database (4)
- CentAUR: Central Archive University of Reading - UK (19)
- Chinese Academy of Sciences Institutional Repositories Grid Portal (4)
- Cochin University of Science & Technology (CUSAT), India (3)
- CORA - Cork Open Research Archive - University College Cork - Ireland (1)
- Corvinus Research Archive - The institutional repository for the Corvinus University of Budapest (2)
- CUNY Academic Works (1)
- Dalarna University College Electronic Archive (6)
- Deakin Research Online - Australia (27)
- DI-fusion - The institutional repository of Université Libre de Bruxelles (1)
- Digital Commons - Michigan Tech (1)
- Digital Commons at Florida International University (2)
- DigitalCommons@The Texas Medical Center (6)
- Diposit Digital de la UB - Universidade de Barcelona (1)
- Duke University (3)
- Escola Superior de Educação de Paula Frassinetti (1)
- FUNDAJ - Fundação Joaquim Nabuco (1)
- Glasgow Theses Service (1)
- Helda - Digital Repository of University of Helsinki (6)
- Hospitais da Universidade de Coimbra (1)
- Indian Institute of Science - Bangalore - Índia (17)
- Instituto de Engenharia Nuclear, Brazil - Carpe dIEN (1)
- Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States (2)
- National Center for Biotechnology Information - NCBI (2)
- Portal de Revistas Científicas Complutenses - Espanha (1)
- QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast (18)
- Queensland University of Technology - ePrints Archive (527)
- ReCiL - Repositório Científico Lusófona - Grupo Lusófona, Portugal (1)
- Repositório Científico do Instituto Politécnico de Lisboa - Portugal (1)
- Repositório digital da Fundação Getúlio Vargas - FGV (1)
- Repositório Institucional da Universidade de Aveiro - Portugal (2)
- Repositório Institucional da Universidade Federal de São Paulo - UNIFESP (1)
- Repositório Institucional da Universidade Federal do Rio Grande - FURG (1)
- Repositorio Institucional de la Universidad de Málaga (1)
- Repositório Institucional dos Hospitais da Universidade Coimbra (1)
- Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho" (87)
- RUN (Repositório da Universidade Nova de Lisboa) - FCT (Faculdade de Cienecias e Technologia), Universidade Nova de Lisboa (UNL), Portugal (1)
- School of Medicine, Washington University, United States (1)
- Scientific Open-access Literature Archive and Repository (1)
- Universidad de Alicante (7)
- Universidad del Rosario, Colombia (2)
- Universidad Politécnica de Madrid (13)
- Universidade de Lisboa - Repositório Aberto (3)
- Universita di Parma (1)
- Universitätsbibliothek Kassel, Universität Kassel, Germany (2)
- Université de Montréal, Canada (3)
- University of Connecticut - USA (2)
- University of Michigan (1)
- University of Queensland eSpace - Australia (33)
- University of Washington (5)
- WestminsterResearch - UK (2)
- Worcester Research and Publications - Worcester Research and Publications - UK (1)
Resumo:
Chitosan is a polysaccharide derived from chitin, mainly of crustacean shells and shrimp wastes. The utilization of chitosan is related to the molar weight and deacetylation degree of the biopolymer. The aim of this work is to study the chitin deacetylation reaction, by the viscosity average molar weight and deacetylation degree of chitosan as a function of reaction time. Deacetylation was carried out in concentrated alkaline solution, 421 g L−1, at 130◦C and the reaction occurred during 4 h. Chitosan paste obtained after 20, 90 and 240 min was used to produce biofilms, which were characterized according water vapor permeability and mechanical properties (tensile strength and percentage tensile elongation at break). During the reaction time deacetylation degree reached 93%, and a 50% reduction in the viscosity average molar weight value in relation to the value of the first 20 min of reaction was found Both reactions presented a kinetic behavior of the pseudo-first order. Biofilm produced from the paste of chitosan with high deacetylation degree showed higher water vapor permeability (WVP), tensile strength (TS) and elongation (E) when compared to films with a low deacetylation.