M.Sc. Tezi Görüntüleme

      In this study, the effects of acetylation on some properties of medium density fiberboards (MDF) were investigated. Firstly, aspen fibers were acetylated with simplified acetylation procedure to a 12.5 weigh percent gain. Acetylated fiber was then formed into fiberboard using 4% and 7% PF, and whereas non-acetylated fibers bonded with 4%, 7%, 10%, 13% PF and 7%, 10%,13% UF. A part of control fiberboards were acetylated during 12 and 24 hour with the simplified acetylation procedure. 16 acetylated fiberboards and 7 fiberboards made with non acetylated fiber using PF and UF were produced to compare their bending strength, tensile strength, water absorption and thickness swelling.

      The properties of PF bonded boards were better than those of boards bonded with UF. Bending strength, tensile strength, water absorption and thickness swelling of fiberboards which made with 10% PF were 21.80 N/mm2, 0.85 N/mm2, 70.65% and 13.66%, respectively. Fiberboards with bonded UF at the same adhesive level these properties were observed 8.53 N/mm2, 0.23 N/mm2, 129.12 % and 40.89 %, respectively.

      Key Words: Acetylation, Acetic Anhydride, Aspen, Fiberboard, Water-Repellent, Dimensional Stability, Chemical Modification.