Study On Acetylating Process And Properties Of Acetylated Kenaf Core

The kenaf core, as the experimental object, was researched in the acetylation process conditions, and then the dimension stability of acetylated kenaf core specimens with different Weight percent gain(WPG), and the compressive property and construction of kenaf core.The effect of the time and temperature of reaction and the concentration of potassium acetate on the WPG of acetylated kenaf core specimens were demonstrated in 20 processes, which were gotten from orthogonal analysis. The three factors had different impacts from different parts of kenaf core, the bottom of kenaf core, the influence degree was: temperature>time>concentration of KAc; the upper of kenaf core, the order was: time>temperature>concentration of KAc.The water absorption and the thickness expansion rate of water absorbing of acetylated kenaf core, were significantly smaller than that of untreated kenaf core, and decreasing with the increase of WPG. And the hygroscopicity and equilibrium moisture content of acetylated kenaf core were as same as the absorption and the thickness expansion rate of water absorption.With SEM analysis, the cellular structure of kenaf core specimens was destroyed to a certain degree, the cell wall was corroded, and the intercellular space of cell was increased, and they were all increasing with the increase of WPG. By analyzing of FT-IR, it was found that hydroxyl groups of acetylated kenaf core largely decreased,and its lipid functional groups increased greatly with the increase of WPG, and in the end, it leads that the surface polarity of acetylated kenaf core was greatly reduced. With XRD observation, the crystallity of cellulose in acetylated kenaf core reduce slightly, the result indicates that the degree of esterification of kenaf core was not high in the process of acetylation.The compressive strength of acetylated kenaf core were smaller than that control groups, and it made a difference of WPG. The different parts had different impacts, for the bottom, the drop-out value had a positive correlation with WPG, and for the top, it had a negative correlation with WPG. Though contact angle analysis, because of the decrease of surface polarity, the contact angle was increased, and increasing with the increase of WPG. Though the modification with decay resistant, we found the acetylation is a efficient way to improve the decay resistant.