The prediction of polymer properties, based on its composition, it is a complex problem with no easy method to obtain directly and accurately results. Among the tribological properties, the friction coefficient and wear rate are the most interesting ones. The polymers based on epoxy resin, with clay as filler, show different properties depending on the clay concentration. This paper presents an analysis of the polymer properties variation with its filler concentration. Due to the tribological processes complexity, mechanical and thermal properties must be taken into account. The aim of this study is to find an optimal concentration value, with minimal influence on polymer properties. All value properties will be used in a neural network model in order to optimize and predict the composite properties.

Taking into account that the tribological processes are a combination of many other processes the aim of this paper is building a neural network model based on mechanical and thermal properties for prediction of the tribological behaviour of an Epoxy- Aramidic composite system. The created epoxy based composites with aramidic powders, were tribological tested with diverse parameters in order to obtain follow properties: wear rate and friction coefficient. Bending and compression tests were performed for obtain main mechanical properties. Thermal tests were performed in order to obtain follow properties: specific heat, thermal conductivity and thermal expansions. With all the studied properties was created an Artificial Neural Network (ANN) model. The created ANN model can perform prediction for tribological behaviour of studied composites.

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Fabric reinforced or textile composites are increasingly used in aerospace, automotive, naval and other applications. They are convenient material forms providing adequate stiffness and strength in many structures. In such applications they are subjected to three-dimensional states of stress coupled with hydro-thermal effects. Assuming that a composite material is a complex structure it is obvious that is hard to describe all its properties in terms of its parts properties. The properties of the composite depend not only on the properties of the components but on quality and nature of the interface between the components and its properties. As reinforcement two types of fiber fabric were used; first one is a simple type fabric of untwisted tows of carbon filaments while the second one is also simple type but as yarn and fill are used alternately untwisted tows of carbon and aramide filaments. There were some problems to be solved before molding: fabric stability during handling, cutting, imbuing the carbon and aramide tows are slipping one on each other leading to fabric defects; generally the epoxy systems do not adhere to the carbon fiber; in order to obtain a valuable material the nature of interface must be the same for polymer-carbon fiber and polymer aramide fiber. In order to solve these problems the two fabrics were covered (by spraying) with a thin film of PNB rubber. Into the rubber solution were also dispersed small amounts of clay (to create a better interface) and carbon black (to improve the electrical conductivity). The rubber presence solves the fabric stability problem; ensures the same type of interface between fibers and polymer matrix; ensures a more elastic interface between fibers and polymer matrix. This treatment induces modification on tensile behavior of fabrics. This study is about mechanical evaluation of such fabrics.

Among composites, the polymer matrix ones are the cheapest and the easiest to form but they show major disadvantages such as poor electrical and thermal conductivity, low fire resistance etc. In the case of any composite, some of the properties may be designed, some of them may be obtained by using an appropriate forming technique and, at least, some of them may be improved by special treatments. In the case of polymer matrix composites the first two ways are recommended if we are taking into account the polymers’ properties while the last one will turn the PMC into an expensive material due to the costs of metal or oxide thin film deposition on polymeric surface. Is it possible to solve all the problems by material design and by developing a convenient forming technique? Powders are used as fillers in order to obtain bi-components composites. The most important aim is about the uniform distribution of particles in matrix. If the fillers’ particles are arranged into the polymer volume is possible to change the electro-magnetic behavior of the obtained composite making this one to act as a meta-material. The powders can be dielectric as talc, clay or ferrite can be magnetic active as ferrite, or electric active as CNT or carbon nano-fibers. All these powders have effects on the electromagnetic, thermal and mechanical properties of the composite. This study is about the influence of fillers on the tribological behavior of particulate composites. Epoxy resin was used as matrix and various powders were used to fill the polymer: ferrite, zinc, clay. The materials were thermally treated in order to reach the best polymer properties. Pin on disk fixture on a CETR-UTM had been used to determine the friction coefficient for each filler concentration. The Wear resistance of each material had been evaluated using the same apparatus but with some modifications.