Biblioteca Digital do Instituto Politécnico de Bragança   Instituto Politécnico de Bragança

Biblioteca Digital do IPB >
Escola Superior de Tecnologia e Gestão >
Tecnologia Química e Biológica >
DTQB - Artigos em Revistas Indexados ao ISI/Scopus >

Please use this identifier to cite or link to this item:

Título: Experimental determination of sequence length distribution of hard segments in polyester-polyurethanes
Autor: Barreiro, M.F.
Dias, Rolando
Costa, Mário Rui
Palavras-chave: Sequence
Issue Date: 1994
Editora: American Chemical Society
Citação: Barreiro, M.F.; Dias, Rolando; Costa, Mário (1994) - Experimental determination of sequence length distribution of hard segments in polyester-polyurethanes. Macromolecules. ISSN 0024-9297. 27:26, p.7650-7653
Resumo: A new analytical procedure based on selective acid hydrolysis was developed to measure the chain length distribution of hard segments (HSCLD) of polyester-polyurethanes. It was tested with polymers made from 4,4'-methylenebis(pheny1 isocyanate), 1,6-hexanediol, and a,w-dihydroxypoly- (hexamethylene adipate) with number-average molecular weight 2200. Heating samples with 0.25 M HC1 solution in dimethyl sulfoxide with 8.2% water for 36 h leads to nearly complete hydrolysis of the ester groups, leaving the urethanes largely unaffected. The resulting mixture of oligomers can be analyzed by size exclusion chromatography, using dimethylformamide at room temperature as the solvent. Experimentally measured HSCLDs were most often very different from those theoretically predicted for homogeneous reaction.
Arbitragem científica: yes
ISSN: 0024-9297
Versão do Editor: The original publication is available at:
Appears in Collections:DTQB - Artigos em Revistas Indexados ao ISI/Scopus

Files in This Item:

File Description SizeFormat
MACROMOLECULES94.pdf403,57 kBAdobe PDFView/Open
Restrict Access. You can request a copy!
MACROMOLECULES94-resumo.pdf133,63 kBAdobe PDFView/Open

Please give feedback about this item
FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex MendeleyEndnote Logotipo do DeGóis 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


© Instituto Politécnico de Bragança - Biblioteca Digital - Feedback - Statistics
Promotores do RCAAP   Financiadores do RCAAP

Fundação para a Ciência e a Tecnologia Universidade do Minho   Governo Português Ministério da Educação e Ciência PO Sociedade do Conhecimento (POSC) Portal oficial da União Europeia