Abstract number: 432

Abstract number: 432 Theme#: 6

Target journal:

Thermal analysis of aging of a matrix polymer material reinforced with a glass fiber.

Nacira SASSANE*, Latifa ALIMI, Tahar GUETTAFTEMAM, Mohamed HASSANI, Skander BOUKHEZAR, Nour Eddine BOUGHDIR, Nihel HAMZAOUI.

Research Center in Industrial Technologies (CRTI),P.O. Box 64 Cheraga. Algiers. ALGERIA n.sasane@crti.dz

ABSTRACT

The objective of this work is to evaluate the influence of temperature variation on the oxidation induction time of a fiberglass-reinforced polymeric matrix material for prosthesis of a tibia.

To do this, we used the differential scanning calorimetry (DSC) technique to calculate the oxidation induction time this last one is the time needed to start the oxidation of the material in an oxygenated environment with an isotherm. And thanks to which we could determine the variation of an isotherm for different temperatures as a function of time.

The experimental results obtained show that the time required to start the oxidation of the material in an oxygenated environment with an isotherm (OIT) decreases with the increase of the temperature of the sample this is confirmed by a hardness test.

KEYWORDS - Thermal analysis, Polymer material, Oxidation induction time (OIT), Hardness test.

1. INTRODUCTION

A matrix / reinforcement composite material is the assembly of two materials where moreover, these materials are not miscible and also have different properties, the reinforcement generally makes it possible to improve the properties of the matrix [1,2].

A link, called an interface, is essential. Charges and additions can add to the composite in the form of powders or liquid, to modify some properties of the matrix (Fig.1.) [3].

Figure 1.Schematic representation of a composite material [3].

Composite materials are currently marking an astonishing advance in their jobs, this is because of their needs in several technical, economic and chemical sectors, these revolutionary materials have demanded in relation to translational materials [4,5].

Most composites subjected to severe stress, for it is necessary to develop a composite with excellent life by conditioning the effects of moisture and weather [6].

The study of polymer aging was based in particular on the observation of the evolution of the chemistry of the material and the ratio of the results of this observation with the degradation of properties of the polymer [7].

2. EXPERIMENTAL METHODS 2.1 Scanning electron microscopy (MEB)

Secondary electron scanning electron microscopy (SE) analyzes were performed on a ZEISS EVO MA scanning electron microscope. With this equipment, nanoscale interactions can be achieved in the samples. Samples are prepared and etched.

The principle of this method is based on the interaction of a focused beam of accelerated monocinetic electrons with the material. The concentration of the elements constituting the alloy can be determined by X-ray energy scattering (EDX) [8].

2.2 Determination of the Oxidation Induction Time (OIT)

Studied the material undergoes the first time to a heating under an inert atmosphere (N2) to melting, after its melting, the material is maintained under isothermal oxygen stream until the start of oxidation. This start of the oxidation results, on the DSC thermogram, by an exothermic peak departure. The OIT (oxidation induction time) is the time between the oxidizing atmosphere and starting oxidation. The DSC equipment used is from the reference NETZSCH DSC 200 PC, the tests are realized at the level of society manufacturing tubes HDPE water and gas(SARL TUBOGAZ), Annaba, Algeria.

2.3 microhardness Vickers

The microhardness was realized by a microdurometer of the MXT-70 type, it is a semi- automatic microdurometer comprising a column of optical microscope in reflection, which makes it possible to target the desired zone on the sample, measurements are made on surfaces plane with a pyramid-shaped diamond indentor with a square base and an apex angle of 136 °.

3. RESULTS

3.1 Scanning Electron Microscopy (SEM)

SEM micrographs show the presence of the micropores may be due to the elaboration method.

Figure 2.SEM micrography of composite with a magnification of 83X.

Figure 3. SEM micrography of composite with a magnification of 1080X.

3.2 Determination of the Oxidation Induction Time (OIT)

Figures 4, 5 and 6 present the DSC thermogram which the measure of the induction time to oxidation (OIT).

Figure 7 shows the variation of induction time as a function of temperature, observed after a temperature maintenance of 35 ° C, the start of the oxidation is marked after 20 minutes and 01

seconds, and after maintaining 100 ° C, the oxidation is declared faster compared to the previous maintenance after 10 minutes.

But after maintaining the temperature at 300 ° C, it is noted that the oxidation is slower than those of previous temperatures. This phenomenon may be due to the chemical consumption of the antioxidant which slow down the oxidation at specified temperatures [9].

Figure 4. Isotherm at 35 ° C as a function of time to determine the OIT.

Figure 5. Isotherm at 100 ° C as a function of time to determine the OIT.

Figure 6. Isotherm at 300 ° C as a function of time to determine the OIT.

Figure 7.Variation of oxidation induction time as a function of temperature.

3.3 microhardness Vickers

The table below shows the values of the micro-hardness (HV) for different temperatures, it is noted that, the value of HV increases with the increase of the temperature, this signifies that the composite becomes more fragile with the increase of the atmospheric temperature.

Table. Values of the HV hardness of composite for orthopedic prostheses of a tibia with different atmospheric temperatures.

Temperature of the specimen

5° 15° 25° 35° 45°

HV values

(Kgf/mm²) 10.02 10.24 12. 06 13.02 15.79

4. CONCLUSION

This study allowed us to study the evolution of the OIT as a function of temperature for a biomaterial intended for the orthopedic prosthesis of a tibia constituted of a polymer matrix reinforced by a fiberglass.

 the time required to start the oxidation of the material in an oxygenated environment with an isotherm (OIT) decreases with the increase of the temperature of the sample.

 The hardness increases with the increase of the temperature, which explains that, the latter favors the fragile behavior of the composite studied.

REFERENCES

[1] R.M. Jones. Mechanics of composite materials, Mc Graw-Hill Company, 1975.

[2] J.M. BERTHLOT. Matériaux composites, comportement mécanique et analyse des structures 4eme édition,Ed TEC&DOC, Lavoisier, 2005.

0 50 100 150 200 250 300

0 5 10 15 20 25

DSC O.I.T : 10,3 min

DSC O.I.T : 23,1 min

OIT ext (min)

Température °C DSC O.I.T : 20,1 min

[3] Centre d’animation régional en matériaux avancés, glossaire des matériaux composite, 2004.

[4] S.J. PICKERING. Recycling technologies for thermoset composite materials–current status , Part A, Aplied Science and Manufacturing, 37, 1206-1215, 2006.

[5] P. KRAWCZAK. Recyclage des composites, Am 5895, Technique de l’ingénieur, 10/07/2011.

[6] J.F. LEBEL. étude des effets de l'humidité sur les composites Recouverts de gelcoat, mémoire pour diplôme de maîtrise et sciences appliquées de l’école polytechnique de Montréal, 1999.

[7] M. ISSELMOU MOHAMED HABIB. Applications des méthodes de l’analyse thermique à l’étude de vieillissement des polymères, thèse de doctorat de l’université de Blaise Pascal, 05 décembre 2013.

[8] T.K. LE. Effet de la fluoration sur la réactivité de TiO2 : applications photocatalytiques, Thèse co–tutelle entre l’université de Pau et des pays de l’Adour et l’université des sciences à Ho Chi Minh ville, 2012.

[9] C. EL MAZRY. Durabilité de produits innovants de robinetterie en polyamide 6,6, thèse de doctorat de l’École Nationale Supérieure d'Arts et Métiers, Paris Tech, 31 Janvier 2013.