Title: Influence of kraft pulping on carboxylate content of softwood kraft pulps
Author: Dang, Zheng; Elder, Thomas; Ragauskas, Arthur J.
Source: Ind. Eng. Chem. Res., Vol. 45: 4509-4516
Description: This study characterizes changes in fiber charge, which is the carboxylate content of fibers, for two sets of kraft pulps: (1) conventional laboratory cooked loblolly pine kraft pulps and (2) conventional pulping (CK) versus low solids pulping (LS) pulps. Laboratory kraft pulping of loblolly pine was carried out to study the influence of pulping conditions, including effective alkali (EA), sulfidity, and pulping temperature, on fiber charge. The results indicated that, when pulping to the same H-factor, low EA charge and low pulping temperature are favorable for increasing bulk carboxylic acid group content of fibers. Sulfidity did not have an obvious effect on bulk or surface carboxylic acid group content of fibers. Surface charge was not significantly affected by pulping temperature. Bulk fiber charge has a hear relationship with water retention value. Roughnesses of holocellulose fiber handsheets were determined by atomic force microscopy (AFM). No apparent relationship between roughness and surface charge of holocellulose fibers was found, but unrefined holocellulose fibers exhibited t least 26% lower root-mean square (RMS) roughness values compared to refined holocellulose fibers. Another set of kraft pulps distinguished by conventional pulping and low solids pulping were investigated to determine the effect of H-Wor and pulping protocol on fiber charge. When bulk fiber charge was plotted against kappa number, pulps from low s o w pulping had a higher slope value than the conventional pulping pulps. The charge on holocellulose fibers approaches a constant value as pulping advances for both types of pulping processes.
View and Print this Publication (1.03 MB)
Pristine Version: An uncaptured or "pristine" version of this publication is available. It has not been subjected to OCR (Optical Character Recognition) and therefore does not have any errors in the text. However it is a larger file size and some people may experience long download times. The "pristine" version of this publication is available here: View and Print the PRISTINE copy of this Publication
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility
Dang, Zheng; Elder, Thomas; Ragauskas, Arthur J. 2006. Influence of kraft pulping on carboxylate content of softwood kraft pulps. Ind. Eng. Chem. Res., Vol. 45: 4509-4516.