The role played by AKD vapours during intenal sizing was investigated using commercial AKD waxes and model surfaces. The model surfaces consist of cellulose and cellulose acetate films deposited on smooth glass slides. These cellulosic films were exposed to AKD vapours at temperatures ranging from 80°C to 175°C for different periods of time. The extent of sizing was followed by measuring the advancing contant angle of water over the treated surfaces. A simple model, considering both physisorption and chemical reaction, was developed and validated with experimental data. The energy of actication of 61.4 kJ/mole was derived from the Arrhenius plot. From a series of indirect techniques, it is concluded that the establishment of a covalent bond between cellulose and AKD is essential in order to introduce permanent hydrophobicity to cellulosic surfaces. The effec of "sizing promoters" on the reaction rate was also examined. Both NaHCO3 and cationic PEI failed to catalyze sizing between cellulose and AKD vapours. The mechanism proposed and the model will shed new light on the phenomena of AKD sizing treatment and sizing migration.
|Number of pages||26|
|Publication status||Published - 1 Dec 1997|
|Event||Transactions of the 11th Fundamental Research Symposium in: teh Fundamentals of Papermaking Materials - Cambridge, United Kingdom|
Duration: 1 Sep 1997 → 1 Sep 1997
|Conference||Transactions of the 11th Fundamental Research Symposium in: teh Fundamentals of Papermaking Materials|
|Period||1/09/97 → 1/09/97|