Study On Preparation Of New Luminescent Plastic With Rare Earth Doped Calcium Carbonate

The CaCO₃:Eu³⁺(CaCO₃:Eu³⁺,Sm³⁺), C aCO₃:Tb³⁺ and CaCO₃:Ce³⁺ phosphor were synthesized via co-precipitation route assisted bymi crowave. Then CaCO₃:Eu³⁺ phosphor was mo dified by st earic acid、KH570and titanate coupling agent （TC-114）, respectively. The cryst allphase, morphology, stru ct ure, si ze and spectrum properties of phosphorwere characterized by X-ray diffraction （XRD）, scanning electronmi croscopy （SEM）, fourier transfor m infrared （FT-IR）, laser particlesize analyzer, photoluminescence and photoluminescence excitation（PL-PLE） spectrum, respectively. The PP/CaCO₃:Eu³⁺ andPET/CaCO₃:Eu³⁺ composites were prepared by melt blending method.The mec hanical properti es, t her ma l properties and lumi nescentproperties of composites were studied, and the results showed that:（1） CaCO₃:Eu³⁺ phosphor was excitated by262and394nm, andthe e mission peak was at614nm, which belonged to red light.CaCO₃:Tb³⁺ phosphor was excitated by230nm and the emission peakwas at614nm, which belonged to green light. CaCO₃:Ce³⁺ phosphorwas excitated by300and340nm, and the e mission peak was at433nm,which belonged to bule light. The exciation and emission of peaks ofCaCO₃:Eu³⁺,Sm³⁺ and CaCO₃:Eu³⁺ phosphor were same, but thelumi nescent intensity of CaCO₃:Eu³⁺,Sm³⁺ phosphor was stronger thanCaCO₃:Eu³⁺ phosphor. The maxi mal e mission peaks of phosphorslocated in the vicinity of614nm, corresponding to electric-dipol etransition⁵D₀�'⁷F₂of Eu³⁺.（2） Then CaCO₃:Eu³⁺ phosphor was modified by stearic acid、KH570and titanate coupling agent （TC-114）, respectively. Thestructures of unmodifi ed and modifi ed phosphor did not change, and theexcition and emission peaks of phosphors did not change. Thelumi nescence intensity of phosphor modified by stearic acid could beenhanced, when the a mount of stearic acid was1mol%, the emissionintensity of phosphor excited by265nm was the strongest. However, the lumi nescence intensity of phosphor mo dified by titanate coupling agentand silane coupling agent could be weakened.（3） The PP/CaCO₃:Eu³⁺ composites were prepared by mel tblending method, and the CaCO₃:Eu³⁺ phosphor particle loadings were0-10wt%. The tensile strength of PP/CaCO₃:Eu³⁺ composites decreased,but the bending strength increased. CaCO₃:Eu³⁺ phosphor could be welldispersed in composites by SEM. But there was obvious aggl omerationin composites, with increa sing the concentration of phosphers. A fast ercrystallization rate, a hi gher melting point, and a lower degree ofcrystallization of c omposites were detected by DSC, compared to thatof pure PP.（4） PP did not show any color under UV light at254nm, whenCaCO₃:Eu³⁺ was added into PP, the whole of PP/CaCO₃:Eu³⁺ composites showed red under UV light at254nm. The excition andemission peaks of composites were the same as phosphers, but thelumi nescence intensity of composites decreased. With increasi ng theconcentration of p ho sph e r, the lumi nescence intensity of compositesbecome i ncreaser.（5） The PP/CaCO₃:Tb³⁺（10wt%） and PP/CaCO₃:Ce³⁺（10wt%）composites were prepar ed by melt blending method, which showedgreen and blue under UV light, respectively. The excition and e missionpeaks of PP/CaCO₃:Tb³⁺ comp osites did not change, but the excition andemissi on peaks of PP/CaCO₃: Ce³⁺ co mposites shift to lift.（6） The P ET/CaCO₃:Eu³⁺ composites were prepar ed by melt blendingmethod, and the CaCO₃:Eu³⁺ phosphor particle loadings were0-5wt%.The tensile strength, i mpact strength and flexural strength ofco mposit es all decreased. CaCO₃:Eu³⁺ phosphor could be welldispersed in compos ites by SEM. A higher crystallization temperatureand a lower degree of crystallization, characteristic vi scosit y and gl asstransition temperature of composites were detected by DSC, comp are dto that of pure PET. PET showed blue under UV light, when CaCO₃:Eu³⁺ was added into PET, the whole of PET/CaCO₃:Eu³⁺ compos ites showedred under UV light at254nm. With increasi ng t he concentrat i on o f phospher, the lumi nescence intensity of composites become increaser.