The effect of recycling process on the chemical properties and wettability of obtained fibers from MDF wastes

In this study properties of fibers recycled from MDF wastes as one of the potential important resources as raw materials for MDF production were investigated.
For this purpose, two different methods including ohmic heating (for 2 and 4 min) and hydrothermal method (at 105˚c for 150 min) were utilized for recycling the wastes of MDF and original fibers were studied as control sample.
The chemical composition of fibers (lignin, cellulose and hemicellulose content), as effective variable on quality of fibers was measured. Also for probing the chemical characteristic of fiber surface, FT-IR test was utilized. In addition, the wettability of fibers also was determined by measuring the contact angels between fibers surface and water drop.
The results showed that the chemical composition of fibers is changed within recycling process. Most changes were occurred in hemicellulose and extractives content. The results of FT-IR test revealed the existence of more carbonyl groups and furfural and lower amount of hydroxyl groups in recycled fibers compared to original fibers which caused by esterification process. The wettability of fibers was decreased after recycling process especially in hydrothermal method.