On the mechanism of sizing with alkylketene dimers
On the mechanism of sizing with alkylketene dimers
复制标题
烷基烯酮二聚体施胶机理的研究
DOI：
--
复制
发表时间：
1986
期刊：
影响因子：
--
通讯作者：
G. Soderberg
中科院分区：
文献类型：
--
作者：
T. Lindstrom;G. Soderberg
研究了不同添加剂对i4c -烷基烯二聚体（AKD）与脱孔漂白硫酸盐浆反应速率的影响，特别是NaHCO和阳离子聚胺-环氧氯丙烷树脂（PAMAM）的影响。HCO、离子和PAMAM对AKD与纤维素的反应速率都有较强的催化作用，在板材成形过程中，两种添加剂同时存在时，存在较强的协同作用。反应速率常数（K, min-l）由去离子水制片时的0.051增加到1。O1在3 × 10-3 mol/l NaHCO， + 0.1% PAMAM存在下。从反应的顺序分析可以看出，HCO离子的催化作用涉及到一个三分子反应。提出了一种涉及循环过渡态的分子反应机理，其中强调了HCO离子的双重功能。这包括纤维素羟基上的氢原子的亲核附着以及向AKD提供质子。
The effects of various additives on the rate of reaction between I4C-alkylketene dimer (AKD) and a decrilled bleached kraft pulp have been investigated, particularly the effects of adding NaHCO, and a cationic polyamideamine-epichlorohydrin-resin (PAMAM). Both HCO, ions and PAMAM have a strong catalytic effect on the rate of reaction between AKD and cellulose, and there is a strong synergistic effect if both additives are present during sheetforming. The reaction rate constant (K, min-l) increased from 0.051 when sheets were made in deionized water to 1 .O1 in the presence of 3 X 10-3 mol/l NaHCO, + 0.1 % PAMAM. From an analysis of the order of reaction, it is suggested that the catalytic effect of HCO, ions involves a trimolecular reaction. A molecular reaction mechanism is proposed involving a cyclic transition state, where a dual function of the HCO, ion is emphasized. This involves nucleophilic attachment to the hydrogen atom of cellulose hydroxyl groups as well as proton donation to the AKD.