The Properties of Wood Tar and Its Application for Manufacturing of Water Soluble Resol-type Phenol Formaldehyde Resins

Autor: Lang-Yue Wu, 吳朗岳
Rok vydání: 2010
Druh dokumentu: 學位論文 ; thesis
Popis: 98
In this study, the distilled wood vinegar and wood tar (Acacia confusa and Cryptomeria japonica) were made from crude wood vinegar under a reduced pressure of 76 mmHg at 50℃. The properties of wood tars stored at different times including viscosity, specific gravity, water content, acid value, FTIR analysis and heating value under different storage conditions such as closed-room temperature, opened-room temperature and closed at 50℃, exposure to different times were examined. Meanwhile, the feasibility of water soluble resol-type formaldehyde-phenol resin (PF), made from phenol and wood tar by a weight ratios of 100/0, 80/20, 60/40 and 40/60 at formaldehyde/phenol mole ratio of 1.5, 1.8 and 2.0, respectively were also investigated. The properties of adhesive such as pH value, viscosity, solid content, gel time, molecular weight, properties of thermal hardening, thermal weight loss and shear strength of plywood bonding of resins were evaluated. The results of GC-MS analysis indicated that the organic components of wood tar can be divided into three components including acidic, phenolic and neutral components, and the acetic acid was the main one of acidic components; the 2,6-dimethoxy-phenol (9.10%) and phenol (5.21%) of A. confusa and C. japonica tar was the main compounds of phenolic components, respectively, as well as the 1,2,4-trimethoxybenzene (5.45%) was the main compound of neutral components for A. confusa tar, and 1,2,3,5,6,8a-hexahydro-4,7-dimethyl-1-(1-methylethyl)-naphthalene (6.17%) for C. japonica tar. Although the viscosity, specific gravity, moisture content and acid value of wood tar were slightly changed with storage time, the FTIR spectra showed that both wood tars had not new peaks appeared or intensity changed with time at different storage conditions. It could be concluded that the storage stability of wood tar was superior, and the best storage condition was room temperature and close one.The results also showed that the PF resins containing wood tar had higher viscosity than pure PF resin, but the gel time were shortened. The GPC analysis indicated that the molecular weight and the dispersion index of PF resins increased with increasing wood tar content. The highest molecular weight of PF resins was 2,043 of phenol/A. confusa tar=60/40 and F/P=2.0. The DSC analysis showed that onset temperature of PF resins had no difference with different F/P mole ratios and wood tar contents, but the peak temperature and reaction heat of the resins containing wood tar were lower than those of pure PF resin. The onset, peak temperature and carbon residue of PF resins containing A. confusa tar were higher than those of C. japonica tar ones by TGA analysis, and the resin containing phenol/A. confusa tar 80/20 and F/P=1.5 had the highest carbon residue of 68.5%. The shear strength of plywood bonding with the PF resins containing A. confusa tar were higher than that of C. japonica tar containing one. And the shear strength of most the resins were superior to the standard of CNS 1349 in normal condition test. The pure PF resin and F/P mole ratio of 1.5 and 1.8 had the best shear strength of 1.01 MPa. Furthermore, the shear strength could be enhanced by adding the A. confusa bark powder to the PF resins and the dosage of 3% by the weight of resin adding was the best one.
Databáze: Networked Digital Library of Theses & Dissertations
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