Study On Preparation And Application Of New Rare Earth Coupling Agent

Coupling agent is an important component in the composite system of inorganic and organic polymer materials, which can improve the comprehensive properties of composite materials and decrease its cost, so it is widely used in many fields such as plastic, rubber, dope, paint, adhesive etc. With the developing of composite materials, new type of multifunctional coupling agent is needs improve much impendent. Now, the hot topic on coupling agent is composite agent with synergistic effect. To improve the comprehensive properties of composites through exert the synergism function of rare earth and titanate, aluminate, we developed new types of rare earth/titanium coupling agent, rare earth/aluminum/titanium coupling agent, which based on traditional preparation theory of titanate and aluminate coupling agent.Firstly, pyrophosphate type titanate and pyrophosphate type aluminate were synthesized in this paper. Then Re-Ti coupling agent and Re-Al-Ti coupling agent were synthesized by titanate, aluminate and rare earth oxide. The technological condition was established according to the viscosity measurement. Structure and thermal stability of the rare earth coupling agent were determined by FTIR spectroscopy, XPS spectroscopy and thermo gravimetric analyzer FTIR spectrum showed the chemic function between rare earth and titanate, aluminate. XPS showed coordination between rare earth and titanate. TG showed that thermal decomposition temperature of ReOT was 262℃, ReOAT was 225℃, both of their thermal decomposition temperature were higher than titanate and aluminate, their have better thermal stability.Through the activation grade, viscosity and settling volume test of modified CaCO₃ by different coupling agent, the result showed that CaCO₃ modified by rare earth coupling agent had better dispersivity and compatibility than titanate, aluminate and WG-1.The mechanical and rheological properties, microscopic morphology of CaCO₃/LLDPE composite modified by different coupling agents were investigated by universal test machine, torque rheometer and SEM. The results indicated that mechanical and rheological properties of CaCO₃/LLDPE composites were enhanced which modified by ReOT and ReOAT compare to which modified by titanate or aluminate. The result of SEM showed that the dispersion and compatibility of CaCO₃ modified by ReOT and ReOAT got better in LLDPE. The rare earth coupling agent improved the mechanical and rheological properties of composites system between different diameter of CaCO₃,and the optimal properties appeared at the size of 800 mesh . The rare earth coupling agent can be widely used in different types of LLDPE, and the best modification result was gained in 9085 LLDPE.