Preparation Technics And Performance Tests Of Chinese Fir Wood/Ca-Montmorillonite (Ca-MMT) Composite Board

In order to meet the need of solid wood flooring, furniture, innerdecorating material and outer building material, intercalation compounding method was used to prepare Chinese fir wood/Ca-montmorillonite(Ca-MMT) composite board to improve properties of Chinese fir wood such as the surface mechanics properties, fire resistance, dimension stability in this research. By virtue of water-soluble phenol formaldehyde (PF) Chinese fir wood and Ca-MMT were compounded through pressure and vacuum impregnation. In term of National Standards hardness, fire resistance, dimension stability, abrasion resistance and water-leaching resistance of the composite board were determined, and the micro-structure of the composite board was characterized by observing SEM graphs and analyzing XRD charts.The following results are obtained:1. The optimum impregnating technology of Chinese fir wood/Ca-MMT composite board has been obtained by orthogonal analysis of pressure and vacuum impregnation, using weight percent gain (WPG) as basic index. Then, using hardness as basic index, the optimum solidification technology of the composite board has been gained. Finally, the optimum preparation technics have been obtained taking into account of properties, preparation technics, cost and so on.2. Chinese fir wood/Ca-MMT (5% concentration original Ca-MMT) composite board is the best among all the experimental composite boards, considering properties and cost. Compared with untreated Chinese fir wood, its oxygen index increases by 6.6%, its hardness in tangential, radial and cross section is 1. 7, 1. 3 and 1. 5 times of that of the untreated wood respectively, its shrinkage in tangential and radial section are both 1/2, and the swelling 1/2 and 2/5 of that of the untreated wood respectively. At 200 revolutions, its abrasion is 0.34% higher than the untreated wood. And its weight percent loss is less than 1. 5% after 3h in boiling water. Oxygenindex, hardness, dimension stability and water-leaching resistance have been improved greatly, except that abrasion resistance decreases a little. 3. From the SEM graphs, it can be seen that Ca-MMT and PF fill in Chinese fir wood macro spaces as cell lumens of tracheids and ray parenchyma cells and pit chambers, absorb on cell wall surface. But the filling is not uniform and the filling in a single cell and pit also has difference. From XRD charts, it can be concluded that PF resin intercalates into the layers of Ca-MMT and enlarges the layers, which makes Chinese fir wood/Ca-MMT composite board become intercalation composite. Ca-MMT and PF resin broaden the amorphous area of Chinese fir wood to a certain degree.This research substitutes Ca-MMT for Na-MMT, and magnifies the size of Chinese fir wood from very small sample to board. The preparation technics of Chinese fir wood/Ca-MMT composite board is feasible through the properties determination and structure charaterization.