Publicação
Comprehensive insights into lignin oxypropylation reaction
| Resumo: | Polyols resulting from oxypropylation are a mixture of oxypropylated lignin and some low molecular weight products (polypropylene oxide oligomers). Normally these oligomers are left in the final mixture since they constitute useful co-monomers, lowering the Tg and the viscosity of the resulting liquefied lignin. In this work a series of polyols based on Alcell lignin have been produced using L/PO ratios (Lignin/propylene oxide, w/v) of 10/90, 20/80, 30/70 and 40/60 and catalyst contents (KOH) between 2-5% (C/(C+L), w/w). The produced polyols and the corresponding extracted fractions (homopolymer and oxypropylated lignin) have been analyzed by size exclusion chromatography (SEC). The obtained results, together with the determined homopolymer content were analyzed with respect to the used formulations (L/PO ratio and catalyst content) and the polyol properties (IOH, viscosity and Tg). |
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| Autores principais: | Cateto, Carolina |
| Outros Autores: | Barreiro, M.F.; Rodrigues, Alírio; Belgacem, Mohamed Naceur |
| Assunto: | Lignin Oxypropylation SEC analysis Properties |
| Ano: | 2013 |
| País: | Portugal |
| Tipo de documento: | documento de conferência |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Polyols resulting from oxypropylation are a mixture of oxypropylated lignin and some low molecular weight products (polypropylene oxide oligomers). Normally these oligomers are left in the final mixture since they constitute useful co-monomers, lowering the Tg and the viscosity of the resulting liquefied lignin. In this work a series of polyols based on Alcell lignin have been produced using L/PO ratios (Lignin/propylene oxide, w/v) of 10/90, 20/80, 30/70 and 40/60 and catalyst contents (KOH) between 2-5% (C/(C+L), w/w). The produced polyols and the corresponding extracted fractions (homopolymer and oxypropylated lignin) have been analyzed by size exclusion chromatography (SEC). The obtained results, together with the determined homopolymer content were analyzed with respect to the used formulations (L/PO ratio and catalyst content) and the polyol properties (IOH, viscosity and Tg). |
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