Lignins as macromonomers for polyurethane synthesis: A comparative study on hydroxyl group determination

• Tipo: Artigo em Revista Científica Internacional
• Data: 2008

Autores

Cateto, CA (Autor) Outra; Barreiro, MF (Autor) Outra; Alírio Rodrigues (Autor) FEUP; Brochier Solan, MC (Autor) Outra; Thielemans, W (Autor) Outra; Belgacem, MN (Autor) Outra

Revista

Título: Journal of Applied Polymer Science

Vol. 109 Nº 5

Páginas: 3008-3017

ISSN: 0021-8995

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 47 Citações

Scopus - 43 Citações

Outras Informações

ID Authenticus: P-003-W8F

DOI: 10.1002/app.28393

Abstract (EN): The hydroxyl group contents of four technical lignins [Indulin AT (Meadwestvaco), Alcell (Repap), Curan 27-11P (Borregaard LignoTech), and Sarkanda (Granit SA)] were investigated in view of their valorization as polyols in polyurethane synthesis. The different hydroxyl group contents were determined by the following methods: titration and H-1-NMR, C-13-NMR, and P-31- NMR spectroscopy. The titration method chosen was on the basis of a standard method commonly used to characterize commercial polyols for polyurethanes synthesis. The values of the total and phenolic hydroxyl contents determined by the different techniques were found to be in good agreement. For the total hydroxyl contents, coefficients of variation of 5.6% (Alcell), 3.2% (Indulin AT), 2.3% (Sarkanda), and 6.2% (Curan 27-11P) were established. For the phenolic hydroxyl contents, a good correlation was observed between data obtained from P-31-NMR and C-13- NMR for all lignin samples, except for the Sarkanda lignin, for which a relatively high coefficient of variation (12.6%) was found. For softwood lignins (Indulin AT and Curan 27-11P), the phenolic hydroxyl content determined by H-1-NMR was always lower than that deduced from P-31-NMR and C-13-NMR spectroscopy. (c) 2008 Wiley Periodicals, Inc.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10