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Doctoral Thesis
DOI
10.11606/T.46.2001.tde-12092006-143935
Document
Author
Full name
Reinaldo Camino Bazito
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2001
Supervisor
Committee
Seoud, Omar Abdel Moneim Abou El (President)
Baptista, Mauricio da Silva
Quina, Frank Herbert
Volpe, Pedro Luiz Onofrio
Zaniquelli, Maria Elisabete Darbella
Title in Portuguese
Novos tensoativos derivados da 2-D-glucosamina
Keywords in Portuguese
Carboidratos
Glucosamina
Química verde
Tensoativos
Abstract in Portuguese
Foram sintetizadas duas novas séries de tensoativos de açúcar derivados da 2-D-glucosamina: os metil 2-acilamido-2-deóxi-6-O-sulfonato-D-glucopiranosídeos de sódio (aniônicos) e os cloretos de metil 2-acilamido-2,6-dideóxi-6-trimetilamônio-D-glucopiranosídeos (catiônicos). Os tensoativos aniônicos foram obtidos pela acilação da 2-D-glucosamina com cloretos de acila (com 8, 12 e 16 carbonos), seguida pela metilação desses derivados com metanol em meio ácido, e posterior sulfatação dos metil glucosídeos com complexo trióxido de enxofre-piridina. Os tensoativos catiônicos foram obtidos pela tosilação dos metil glucosídeos, seguida pela quaternização com trimetilamina e troca do contra-íon tosilato por cloreto com resina de troca-iônica. Esses tensoativos apresentaram c.m.c. similares a de outros tensoativos iônicos de cadeia hidrofóbica de igual comprimento, mas energias livres de transferência do grupo polar para a micela muito mais favoráveis. Esse fato foi atribuído à formação de ligações de hidrogênio entre os grupos polares do tensoativo na micela, e à hidrofobicidade do açúcar. As micelas formadas apresentaram números de agregação maiores que os obtidos para outros tensoativos, provavelmente devido às interações atrativas entre os grupos polares.
Title in English
New surfactants based on 2-D-glucosamine
Keywords in English
Carbohydrate
Glucosamine
Green chemistry
Surfactants
Abstract in English
Two new sugar-based surfactant series were synthesized from 2-D-glucosamine: sodium methyl 2-acylamido-2-deoxi-6-O-sulfonate-D-glucopyranosides (anionic) and methyl 2-acylamido-2,6-dideoxi-6-trimethylamonium-D-glucopyranoside chlorides (cationic). The anionic surfactants were obtained by the acylation of 2-D-glucosamine with acyl chlorides (with 8, 12 and 16 carbons), followed by the methylation of these derivatives with methanol in acidic media, and the sulfation of the methyl glucosides with sulfur trioxide-pyridine complex. The cationic surfactants were obtained by the tosylation of methyl glucosides followed by the quaternization with trimethylamine and exchange of the tosylate contra-ion with chloride ions on an ion exchange resin. These surfactants showed c.m.c. similar to other ionic surfactants with equal hydrophobic chain lengths, but more favorable free energies of transfer of the polar head to the micelle. This fact is attributed to hydrogen bonding between the head groups of the surfactant in the micelle, and the hydrophobicity of the sugar moiety. The micelles of these surfactants showed aggregation numbers larger than those obtained for other surfactants, problably because of head-group attractive interactions.
 
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Publishing Date
2007-01-03
 
WARNING: The material described below relates to works resulting from this thesis or dissertation. The contents of these works are the author's responsibility.
  • BAZITO, Reinaldo C., and EL SEOUD, Omar A.. Sugar-Based Surfactants:  Adsorption and Micelle Formation of Sodium Methyl 2-Acylamido-2-deoxy-6-O- : sulfo-d-glucopyranosides [doi:10.1021/la0117552]. Langmuir [online], 2002, vol. 18, n. 11, p. 4362-4366.
All rights of the thesis/dissertation are from the authors
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