Propylene-ethylene Copolymer Filled Nanocomposites:Influence of Zn-ion Coating upon Nano-SiO_2 on Structural,Thermal,and Dynamic Mechanical Properties

摘要

Propylene-ethylene copolymer (EP) nanocomposites based on nano-SiO_2 with and without Zn-ion coating were developed by conventional melt blending technique in a sigma internal mixer.Two composites each with 2.5 wt filler were developed.The first composite was made by melt blending EP with nano-SiO_2 in a co-rotating sigma internal mixer.The second one was obtained by melt blending the same EP,but with Zn-ion coated nano-SiO_2.In case of Zn-ion coated nano-SiO_2 filled EP,wide-angle X-ray diffraction study (WAXD) showed a decrease in interplanar distance and lamellar polymer crystal size when compared to nano-SiO_2 filled EP.Differential scanning calorimetric (DSC) results showed Zn-ion coated nano-SiO_2 acting more as an effective nucleating agent than that of the nano-SiO_2.Thermogravimetric analysis (TGA) results showed improved thermal stability for EP in the presence of both the nanofillers.However,the thermal stability of Zn-ion coated nano-SiO_2 filled EP is higher than that of the nano-SiO_2 filled EP.Scanning electron microscope (SEM) study reveals that the Zn-ion coated nano-SiO_2 homogeneously distributed in the matrix,whereas nano-SiO_2 forms chainlike aggregates in the matrix phase.Dynamic mechanical analysis (DMA) study indicates that both the fillers increase storage modulus,E';this increment is more prominent in nano-SiO_2 filled EP due to the formation of chain-type aggregates of nano-SiO_2.