The Research On Phenolic Resin Modified By Nanoparticles

In the dissertation, the trends of research and development of macromolecule material modified by nanoparticles were reviewed. The application of nano-materials in polymers and the research present situation of the phenolic resin were discussed. Based on the literature and the requirement of enterprise, we proposed the research methods using nanoparticles to modify the phenolic resin binder for magnesite-carbon brick use. The major aim is to develope a high performance and novel modified phenolic resin using nanoparticles as reinforce. The modified phenolic resins with higher solid content and residual carbon, higher decomposition and oxidation resistance temperature, and room temperature viscocity below 100 P were synthesized. Two process routes for the synthesis of modified phenolic resins are as follows:The first process route: the modified phenolic resin was synthesized by a sol-gel process using in-situ formed nanosized silica. The effect of react conditions on phenolic resin was investigated.The normal detection indexes of the phenolic resin prepared by the orthogonal test optimization were better than that of the phenolic resin without modified. Comparison to the unmodified phenolic resin, the residual carbon of the modified phenolic resin reaches to 50.75% and increases about 10wt%. The improved phenolic resins were characterized by IR, TG-DTA and FESEM analyses. The results show that the interaction between SiO2 nanoparticles and phenolic resin lead to the decrease of concentration of phenolic hydroxyl groups, and introduce the impurity atom Si to the phenolic resin molecule chain, which promote the thermal resistance and stability of phenolic resin. FESEM images show that fiber-like carbon were formed from the modified phenolic resin after carbonization under 800℃, which may result in the reinforcement of phenolic resin.The second process route: the nanosized carbon blacks were chemically oxidized by the mixed acids of sulfuric acid and nitric acid, which promoted the formation of surface functional groups on carbon black. This carbon black then was used to the in-situ synthesis the modified phenolic resin by mixing nano-carbon blacks dispersed in the oligomers solution with starting materials. The normal detection indexes of modified phenolic resin achieved the reqirement when the quantity addition of modified nano-carbon blacks was 3wt%. The maxium value of residual carbon is 47.21% and increases about 7wt% comparison with unmodified phenolic resin. The modified phenolic resin was characterized by IR and TG-DTA analyses .The results show that the main impact force was the strong physical adsorption directly and only a little of chemical bonds between nano-carbon blacks and phenolic resin.The first thermal decomposition temperature and the carbonization temperature was raised about 170℃and 178...