Prepaeration And Characterization Of Polymer Filled With Nano Particles

The microscopic image of nanocomposite, the toughening mechanism and the modification of PP by organo-montmorillonite or nano-CaCO3particles, LDPE by nano-CaCO3particles and Acrylonitrile-Butadiene-Styrene (ABS) by nano-CaCO3particles are systematically investigated in this paper. The processing method of the experiment is discussed in this paper. The modification condition of nanocomposites is investigated by testing of impact strength, tensile strength and bending modulus. The viscous-elastic properties of composites are analyzed by DMTA. The microscopic structure of crystal is described and discussed on the basis of PLM; the dispersion of organo-montmorillonite and nano-CaCO3particles in the matrix is described and discussed based on the results of TEM; the crystallinity of the composite is discussed on the basis of the results of DSC. The thermal stability of composites is analyzed by Thermo gravimetric analysis (TGA). The mechanism of toughness and reinforcement is also studied.The results of the experiments are:nano-CaCO3particles and organo-montmorillonite could be dispersed uniformly in the composites at a nanometer scale with adequate processing technology; the toughness and flexural modulus of the composite are improved dramatically at the same time. When Org-MMT added2PHR, the impact strength of nanocomposite gets the maximum,23.3kJ/m2, which is about1.21times than that of the neat PP; the bending modulus reaches116.1MPa, which is1.14times than that of the neat PP. Synchronously, the loss temperature in5%by TGA was395.1℃, which is112.1℃higher than that of the neat PP. The DMTA results shows that the storage modulus (E’) and the loss modulus (E") are improved simultaneously.The characterization and analysis of the microstructure of composite shows that nano-CaCO3particles and organo-montmorillonite has been dispersed uniformly in the composite at a nanometer scale. In the organo-montmorillonite/polypropylene nanocomposites, layered particles have an orientation along with the orient of the shearing force. With addition of nano-CaCO3, the crystal temperature and the onset crystal temperature increase evidently, whereas the heat enthalpy of crystalinity decreases. It is clear that, by acting as hetero-nuclei, the presence of the nano-CaCO3has greatly affected the crystallization of PP. Thus, the birefringence of the spherocrystals became obscure and blurring. The crystal size in the composite is also refined.In nano-CaCO3/ABS composites, the results show that the E-materbatch (EVA as matrix) is more advantaged than the A-masterbatch (ABS as matrix). The SEM and TEM results show that nano-CaCO3particles had been dispersed uniformly in the composite at a nanometer scale.The tensile yield strength of the nano-CaCO3/LDPE composite is improved dramatically while their tensile strength keeps constant in the mean time. When nano-CaCO3added35%, the tensile yield strength of nanocomposite gets9.13MPa, which is about1.24times than that of the neat PP. At the same time, the elongation at break is keeps. The flexural modulus of the nano-CaCO3/LDPE composite is also improved dramatically.The toughness and reinforcement mechanism of crystal composites is that the nanoparticles have effect on the composites through interface reciprocity-initiation, pinning and termination crazing (silver streak)-crystalinity. In different systems, the proportion of mechanism is not the same. The microstructure of composites had changed evidently because of the nanoparticles addition.In tensile process of the organo-montmorillonite/polypropylene nanocomposites, an orientation and slippage of layered silicate and new interface formation between layered silicate and matrix have a primary effect on the properties of the composites.The toughness and reinforcement mechanism of noncrystalline composites is that the nanoparticles effect on the composites through reciprocity-initiation, and termination crazing (silver streak)-shear yield stress-interfacial decohesion (debonding) between particles and matrix. Nanoparticles introduce the shear yield stress of matrix and Interfacial decohesion (debonding).The investigation of the experiment has produced some references for both Polymer’s modification and processing, which could be also valuable for further application of these polymers. The results of pilot-scale experiment show that the batch formula and the processing technique are feasible.