Study On Preparation And Fluorescent Properties Of Rubber/Rare Earth Composites

Lanthanide complexes exhibit good luminescent properties based on 4f electronic transitions of lanthanide ions which have sharp and intense emission bands and a wide range of luminescent lifetimes. Compared with the lanthanide complex, lanthanide complexes/polymer composites exhibit improved processability, chemical stability and mechanical strength due to the polymer nature.Rare earth oxide (Re2O3, Re=La, Sm, Dy, Eu)/carboxylated styrene butadiene rubber (XSBR) composites were prepared by mechanical blending and crosslinking. The curing characteristics of these complexes showed the four kinds of rare earth oxides could accelerate the cure rate. The results of the mechanical tests revealed that the hardness, tensile strength, tear strength and modulus of the composites were improved after filling rare earth oxides, while the elongation was decreased. Among the four kinds of rare earth oxides, La2O3 showed the best effect. The fluorescent results indicated the obtained composites (except for La2O3/ XSBR composite) had certain fluorescent properties. Sm(Pht)3phen was synthesized and filled to acrylonitrile-butadiene rubber (NBR). Compared with (SmCl3+KHPht+phen)/NBR, Sm(Pht)3phen/NBR composite has better mechanical properties and fluorescent property.A novel series of rare-earth complex Re(sal)3phen(Re=Eu,Dy,Sm)have been synthesized and filled to NBR through solution mixing to prepare Re(sal)3phen /NBR composites. The structure of the complex was confirmed by Fourier transformation infrared spectrometer. The fluorescent experiment suggested effective energy transfer occurred.More studies were carried on the Eu(sal)3phen /NBR composite. The average particle size of the complex in the composites was much smaller that that of pure complex and the complex particles were well dispersed in NBR matrix. The results of X-rays diffraction revealed Eu(Sal)3Phen was a crystalline complex and its structure changed in the composites. The fluorescent intensities of the composites increased with increasing Eu(Sal)3Phen content, and fluorescent quenching was not observed even when Eu(Sal)3Phen content was up to 25 phr. Increasing Eu(Sal)3Phen content could improve the monochromatic of the composite and the asymmetry of the coordination environment of Eu ions.Moreover, Fluorescent intensities of the composites at a given complex content increased with increasing the heating temperature to remove the tetrahydrofuran solvent from the solution,which is attributed to the fast evaporation of the solvent that influences the morphology of Eu(Sal)3Phen.