Mechanical,morphological,and luminescent properties of strontium phosphorescent filler-filled NR/PP/PEC blends as affected by processing design

Abstract

Photoluminescent material was successfully prepared by blending europium-doped strontium aluminate phosphorescent filler (SrAl₂O₄:Eu²⁺) with terpolymer of natural rubber/polypropylene/propylene–ethylene copolymer (NR/PP/PEC). The influence of alternative processing design, that is, mixing method (simple blend (SB) or dynamic vulcanization (DV)) and mixing sequence (direct method or precompounding method) on mechanical, morphological, and photoluminescent properties of the SrAl₂O₄:Eu²⁺-filled NR/PP/PEC blends, was systematically studied. The results revealed that mechanical and photoluminescent properties can be improved by the control of rubber vulcanization and phase morphology. The dynamically vulcanized blends (DV1 and DV2), in which the NR phase was vulcanized during melt mixing under high shear and had vulcanized NR particles dispersed in the continuous PP and PEC matrices, showed superior mechanical and photoluminescent properties over the SB with co-continuous phase morphology. Controlled location of rubber additives in the NR phase by precompounding (DV2) gave the highest light emission intensity with the longest decay time.