Study On Synthesis Of Zinc Borate And Surface Modification

As an important kind of inorganic flame-retardants, zinc borate has attracted much attention for its excellent thermal stability, fume suppression and no toxicity etc. However, as an inorganic salt, its poor dispersability in polymer would decrease the mechanical properties of the filled polymer.In this paper, it has been done to investigate the factors of surface modification of zinc borate, including the surfactants sorts, adding times and different dosages. The zinc borate was characterized by IR, SEM and XRD.Conclusions:1. A series of aliphatic anionic surfaceactive agents which consisted of 8,12,16,18 of carbon atoms were studied as the modifying agent. It was found that, with the increasing of the carbon atoms, the contact angle with water increased and the oil absorption decreased, which means the effect of modification was better.2. Amount the surfactants used in the research, the contact angle with water which modificated by the mixture of sodium stearate and OP was the biggest, and sodium stearate was bigger. Water dripping was absorbed immediately by the zinc borate modificated by OP.3. Increasing of surfactant dosage to some extent, the contact angle of zinc borate with water tended to become bigger. Based on the experimental results, the optimum dosage of the mixture rate was 1.5 % sodium stearate and 2 % OP. The optimum dosage was 2 % when using sodium stearate along.4. With the delay of the adding of surfactants, the diameter of the modified zinc borate tended to become bigger, especially the zinc borate modified by OP for emulsification.Mirowave irradiation has been used as a new heating method in the synthesis process of zinc borate. The reaction was much faster than conventional heating method. It took only 3 hours to synthesize ZB-2335 under microwave power being 600 W. The study on zinc borate modified by surfactants on microwave showed its contact angle with water was smaller than conventional one.The study on modified zinc borate using as a flame retardant showed it had a better lipophilic. When the additive amount was less than 15 %, the mechanical properties of PVC including the modified zinc borate was much better than the unmodified one. It means that the modified zinc borate has a better dispersability in PVC.