Abstract: The surface organic modification of ultrafine RE2O3 (RE2O33, RE = La, Ce, Pr, Nd, etc.) was studied. Hyperbranched poly(amide-ester)（HBPAE）were obtained from solution polycondensation of an AB2-type monomers（prepared in a reaction between diethanolamine and succinic anhydride at room temperature）, which was compounded with RE2O3 and was uniformly coated on the surface of RE2O3 particles through mechanical stirring. The HBPAE/RE2O3 composites were characterized using FTIR, elemental analysis, XPS, SEM, XRD, and TGA and compared with raw RE2O3. It was found that 4.71 % of HBPAE were attached with RE2O3 particles via coordination bonding, thus the modification was limited on the surface of RE2O3 and no effect on the crystal structure of bulk RE2O3 particles. The thermal stability of HBPAE/RE2O3 could be tailored by the ratio of HBPAE to RE2O3. The dispersion stability of RE2O3 in organic solvents was also improved by the surface coating.

Key words: hyperbranched poly(amide-ester), mix rare earth oxides, thermal stability