Preparation And Characterization Of Nylon6/Na-MMT Nano-masterbatches And Its Composites

In this paper,two methods of preparing Nylon-6/Natural-MMT nano-masterbatches was studied.One is the in-situ polymerization,the other is water-assisted melt compounding.The structures and properties of the nanocomposites which prepared by nano-masterbatches were also characterized in detail.In the experiment,we used the natural MMT which have the cation exchange ability between 90 mmol/100g and 120mmol/100g.In the in-situ polymerization,firstly we prepared the mixture of MMT and caprolactam;then drying,finally,we get the masterbatches by the polymerization between layers of MMT;In the water-assisted melt compounding process,we added the MMT slurry into the melt nylon-6 because water is the natural sweller of MMT and the natural lubricant of nylon6,we can get the nano-masterbatches by strong shear and vapor expansion.The result shew that these masterbatches were readily dispersed into the molten PA6 matrices yielding intercalated/exfoliated layered silicate nanocomposites,the corresponding size had reached a nanometer. The results of XRD and DSC shew that montmorillonite play the role of iso-phase nucleation in the PA6 matrix,it decreased crystallization rate parameter K,reduced the crystallization activation energy and half crystallization time of pure PA6.we prepared two composites by diluting the 15%MMT content masterbtch and 30%MMT content masterbatch with nylon6 in the proportion of one to four and one to nine.Then, characterized its properties.In comparison with nylon6,The tensile-strength of two diluted samples had increased by 24%and 11%, the Elastic modulus had increased by 49.8%and 22.9%,the bending strength of two diluted samples had increased by 66.6%and 26%,the Flexural modulus had increased by 85%and 16.7%.The heat deflection temperature also increased obviously.In comparison with nylon6,the heat deflection temperature of 1:4 diluted sample and 1:9 diluted sample had increased by 39.5%and 26.3%respectively under the press of 0.45Mpa.The heat deflection temperature of two diluted sample had increased by 37.9%and 20.9%respectively under the press of 1.8MPa. The rheological behaviors of nanocomposites which prepared by nano-masterbatches were studied.The results shew that the nanocomposites exhibits similar shear thinning behavior as pure PA6,it belonged to pseudoplastic and non-Newtonian fluid,the non-Newtonian index and the apparent viscosity of nanocomposite were lower than the pure PA6.