Addition of Ascorbic Acid or Purified Kraft Lignin in Pulp Refining: Effects on Chemical Characteristics, Handsheet Properties, and Thermal Stability

Emilia Vänskä, Tuomas Vihelä, Leena-Sisko Johansson, Tapani Vuorinen


The effects of two pulp pretreatments, impregnation with ascorbic acid (AA) or purified kraft lignin (KL), on bleached pulp refining were investigated by examining and testing handsheets made from these pulps. The AA pretreatment of the pulp amplified the depolymerization of the cellulose and notably impaired the strength properties of the pulp handsheets. The effects were enhanced upon the combination of the AA pretreatment and intensive refining. Furthermore, heat treatments (at 225 °C, 30 min, in water vapor atmospheres of 1 and 75% (v/v)) promoted the depolymerization of cellulose and the total color difference in the AA impregnated handsheets more than for the KL impregnated and reference handsheets. In contrast to AA, the KL pretreatment of the pulp improved the burst index stability of the refined pulp handsheets after the humid thermal treatment (75% (v/v)). In addition, the total color difference of the KL impregnated handsheets was lower than the AA impregnated and reference handsheets.


Ascorbic acid; DP; Lignin; Pulp; Radical scavenger; Refining; Thermal degradation; UVRR; XPS

Full Text:


Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022,; Lucian A. Lucia, (919) 515-7707, URLs:; ISSN: 1930-2126