Study On The Interfacial Adhesive Properties Of Particulate-Filled Polymer Composites

Nowadays, more and more attentions have been paid to the polymer composites because of their excellent properties. Polymer composites are formulated of high modulus filler and low modulus polymer matrix. The compatibility and interfacial property between filler and polymer matrix are not well, which affect the mechanical properties of the polymer composites. Therefore, many scientists of the world have paid great attentions to study the interfacial properties of polymer composites. We always add some modifiers, such as coupling agent, solubilizing agent, to the composites when we modify the interfacial properties. But there are limited interfacial additives that we can use nowadays. There are some experienced ways to select the additives when modifying the interface. We have no systematic theories and efficient ways to direct the modification of interfacial properties.To solve these problem, this article has given a way to modify the interfacial layer by testing the surface properties of filler and polymer matrix. Some workable interfacial additives have been synthesized.Firstly, to the particulate filled Polyurethane composites, we have detected the contact angle between test solvent and filler or polymer matrix by the surface analysis. The surface tension, polar force parameter of the surface tension, apolar force parameter of the surface tension and polar fraction had been calculated. From the parameters, the interfacial tension, work of adhesion, fracture energy between filler and polymer matrix had been estimated. The interfacial adhesion properties had been estimated by means of these parameters and tested by mechanical test. We believed that it is the bipolar area of the filler that are easier fracture points from the force analysis of a single particle .The ideal interfacial layer must have a changeable layer which can absorb the energy by the fracture, the mechanical properties will be improved by the modified layer. We have studied the SEM micrographs of the mechanical fracture surface of polymer composites. Modifying principles to theinterfacial layer of polymer composites have been given, some novel interfacial additives have been designed and synthesized .The properties of the additives have been studied. We find that these additives can modify the surface properties of filler and improve the mechanical properties of polymer composites. It is proved that the interfacial additives that we have synthesized are some sufficient additives to the paniculate filled Polyurethane elastic system.Secondly, to the paniculate filled Epoxy composites, the interfacial adhesive properties between them had been estimated. We have found that the brittle material, such as Epoxy, must have excellent interfacial adhesive strength and changeable layer which can transmit stress, induce craze and yield to contract the spread of the craze from force analysis of a single particle. The interfacial modification of the system have been given, the solubility parameters of the additives have been calculated .The compatibility between the matrix and the additives have been estimated. The mechanical test had proved that the additives can improve the mechanical properties of the paniculate filled Epoxy composites. The SEM micrographs had been studied and found that the interfacial properties are excellent.