Study On Synthetic Process And Properties Of Environmental-Friendly PF For Refractory Material

With the developing of the foundry industry technology and environmental awareness, Requirements of the ability of high-temperature furnace and environmental protection have greatly improved. The ordinary PF-based refractory bricks have increased production costs because of short life, being harmful for the environment and worker health problems. Therefore, environmental-friendly PF with high char yield conforms to the development of refractory material adhesive.In this paper, thermoplastic PF of high char yield with low free phenol has been studied, including choosing synthetic routes, the optimization of reaction conditions, the modified process of research and so on, mainly on improving its environmental performance and high char yield.Thermoplastic PF of high char yield with the high-ortho-substituted structures was prepared, free phenol content reduced. In this study, according to content of free phenol (%) monitored by gas chromatograph, the influence of various factors on the free phenol was studied, and theoretical analysis was carried out on its experimental results. Optimum reaction conditions is oxalic acid and zinc acetate being as a catalyst, the ratio of P/F being 1:0.7, the reaction temperature being 95-100℃. The content of phenol reduced to below 1%, far below the target of 4%. Triflate was used to catalyze the reaction for the first time, making the content of phenol reach to about 1% in a short time. Test of IR shows that, PF of the environmentally friendly process contains the high-ortho-substituted structures, which makes its curing speed being more 2 or 3 times than that of common PF. According to test of TG, curing temperature of the thermoplastic PF is between 150℃and 220℃, and the solid content is about 80%.Besides, feasibility study of environmentally modification technology was made based on the new synthesis, which indicated that modified PF with one percent boric acid raised char yield, but raised the content of free phenol as well; modified PF with five percent bisphenol A reduced the content of phenol significantly; modified PF with tar had a bad impact both on the appearance and viscosity, through increased the char yield.