| With the rapid development of construction and transportation in china, it has the big demand for outdoor using wood composite materials such as wood based cement template,container flooring,and higher performance of materials is required.as an adhesive possesses good waterproof performance, excellent durability and high adhesive strength, using phenolic resin impregnated paper as surface material can effectively improve the performance of wood composite materials and useful life.But long curing time and high curing temperature is the main defects which Influence phenolic resin widely used.Therefore, it is necessary to develop a lower hot pressing temperature and high curing speed phenolic resin.This paper first introduced the general situation of phenolic resin and its application in wood industry. Analysis phenolic resin research direction in domestic and international wood industry. It is point out that using divalent metal ions catalyst and advanced synthesis process can make resin cure fast in low viscosity. Then the divalent metal ions catalyst of phenolic resin was screened out, the results show that the production of phenolic resin easily control and performance is good using CaO as a catalyst. And the synthetic raw material molar ratio, reaction temperature and time, formaldehyde release scheme was researched to find out the best formula and synthetic process of phenolic resin。The synthesis and cure properties of phenolic resin was studied by high performance liquid chromatography, fourier infrared spectrum and differential scanning calorimetry. Monosubstituted polymer and disubstituted polymeric of phenolic resin was qualitative and quantitative analysed by high performance liquid chromatography. The synthesis reaction mechanism and the structure characteristics of phenolic resin was studied by fourier infrared spectral analysis. Through the analysis of different curing samples by fourier infrared spectrum and differential scanning calorimetry, with curing reaction, the changes of different groups content and the exothermic absorption of cure reaction was studied. The results showed that using CaO as catalyst is favorable for ortho substituted polymer, rest more high reactivity para substituted polymer, Make the cure reaction of phenolic resin completed easily. The influence of pH and catalyst type on the curing reaction of phenolic resin was researched. The results show that the when the pH of phenolic resin catalyzed with CaO change from alkaline to weak acidity, the curing reaction of resin can completed more quickly, and catalyst type cannot only affect the structure of the phenolic resin, but also plays an important role in the curing reaction of the phenolic resin.Finally, impregnation and drying process of formaldehyde resin impregnating paper was studied in the best formula and synthesis process condition. The results show that the second impregnation drying process was the best drying process and140℃～150℃was the best drying temperature, drying process is easy to control, the first and second drying time with diffient glue content was found out. In order to confirm the performance of phenolic resin catalyzed with CaO, phenol formaldehyde resin impregnating paper was used for making veneered man-made board. Simultaneously hot-press veneered process was study. The result indicated that the best hot-press temperature is140℃, the best hot-press time is4min. The wearability, alkali resistance and surface bond strength have reached the national standard. The drawbacks of PF impregnating resin such as slow cure time, high cure temperature was solved.In summary, this article research, and in fact all has the reference value to the PF resin development and the applied research in the theory. |
PDF Full Text Request