New insights into the AKD sizing mechanism
Kyle J. Bottorff and Mark J. Sullivan, Hercules Incorporated, Wilmington, Delaware, USA
Keywords: Alkylketene dimers, AKD, Reaction mechanisms,
Solid State "C NMR, Sizing, P-Ketoacid, P-Keto calcium salt,
P-Keto ester, AKD oligomers.
SUMMARY: Paper samples sized with 13C labeled alkylketene
dimer (AKD) dispersions were characterized by solid state
carbon NMR resulting in direct evidence supporting the forma-
tion of AKD-cellulose P-keto esters on AKD sized paper.
A series of AKD reaction products that may
Pure &Appl. Chem., Vol. 69, No. 3, pp. 601-604, 1997.
Printed in Great Britain.
Q 1997 IUPAC
Generation of radical species by one electron
oxidation with metallic compounds for the
construction of carbon skeletons
Department of Chemistry, School of Science, The University of Tokyo,
Hongo, Bunkyo-ku, Tokyo 113, Japan
Abstract: By oxidation of P-ketoacids, cyclopropanols, and acyl chromate complexes
with tris(2-pyridinecarboxylato)manganese(III) (Mn(pic)g), a-keto, p-keto, and alkyl
radicals are generated respectively, which react with
bond. Alkylketene dimers can also react with water,
forming an unstable P-ketoacid, which decarboxyl-
ates to the corresponding ketone.
SOME AKD - REACTIONS
R,-CH,-cX-CH,-R, + ~ ' b ~ ( ~ )
x = C labell ing position
Fig. 1. Some possible AKD-reactions.
26 Nordic Pulp and Paper Research Journal no. 111 986
The hydrolysis was critical in earlier AKD-disper-
sion formulas, whereas the rate of hydrolysis is
apparently very slow in new AKD-formulas (4). The