Resumo

SANTOS, Fernando dos  e  CURVELO, Antônio Aprígio S.. Use of lignins in phenolic resins: 1. Preparation of novolacs from lignosulfonates 49. Polímeros [online]. 1999, vol.9, n.1, pp.49-58. ISSN 0104-1428.  https://doi.org/10.1590/S0104-14281999000100007.

This work describes the production of high value products using lignins obtained from industrial pulping processes. Novolac phenolic resins were prepared employing ammonium lignosulfonates and sodium lignosulfonates (with different residual sugar contents) in a partial replacement of phenol. The resins were prepared using the same conditions employed in the industrial phenolic resins production. The lignin based resins were characterized by chemical analysis, molecular weight distribution and thermal analysis. The resins prepared using lignosulfonates showed higher reactivity with hexamethylenetetramine (crosslink agent). This behavior lead to another economic advantage as consequence of the reduction in the expended time for molding cycles.

Palavras-chave : Lignosulfonates; phenolic resins; novolac.

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