Marcos BATISTELLA*a, Belkacem OTAZAGHINEa, Rodolphe SONNIERa, Jos-Marie LOPEZ-CUESTAa, Carlos PETTERb , Luca FAMBRIC*marcos.batistella@mines-ales.frA Ecole des Mines dAles France B Universidade Federal do Rio Grande do Sul Brazilc Department of Industrial Engineering - University of Trento - Italy

Fire and mechanical properties of Polyamide 6/Kaolinite composites1

C2MACentre des Matriaux1IntroductionFire behaviorUse of mineral fillers as fire retardantsAluminium hydroxide or Aluminium TriHydrate 2 Al(OH)3 Al2O3 + 3 H2O needs 1051 J/g Al(OH)3Clays

Few studies of kaolinite as filler

2IntroductionMaterials & MethodsResults & Discussion ConclusionSWang, L., et al. Polymer Degradation and Stability, 95(4), 572578.

CMGDCentre des MatriauxFire retardancy can be achieved using hydrated mineral fillers such as alumina trihydrate or magnesium hydroxide. However, high filler content are required to obtain satisfactory improvement. The action of these fire retardants are based on the release of water, that will cool down the degradating polymer and dilute combustion gases. This degradation led to some delay in the inflammation but does not provide a protection of the substrate.

In the case of clays, a lot of studies concerned the use of intercalated/exfoliated mmt, but only one concerns the use of intercalated kaolinite and, at the best of our knoledge, none concernes the use of non exfoliated kaolinite. With this reason in mind, in this study.....2IntroductionKaolinite

Kaolinite compositesMechanical properties & Surface modification3

IntroductionMaterials & MethodsResults & Discussion ConclusionSBuggy, M., et al. (2005). Composites Part A: Applied Science and Manufacturing, 36(4), 437442.Itagaki, T., Matsumuraet al. (2001). Journal of Materials Science Letters, 20(16), 14831484.Gardolinski, et al. (2000). Journal of Materials Science, 35(12), 31133119.Al2Si2O5(OH)4CMGDCentre des MatriauxKaolinite is a 1 1type clay. It is composed by two layers: An octahedral sheet of alumina and a tetrahedral sheet of silica. It have a placar form.

Most of the studies concerned the mechanical properties of composites and surface modification of kaolinite with silane coupling agents.

3MaterialsPA6:

Kaolinite

4Mean Diameter (m)Specific surface (m2*g-1)Aspect Ratio (l/d)Kaolinite K10.812.212Kaolinite K20.2195IntroductionMaterials & MethodsResults & Discussion ConclusionSDensityTensile modulus (Mpa)Tensile Stress (Mpa)Melt Flow

AQ270001.14300090

CMGDCentre des Matriaux4Materials5IntroductionMaterials & MethodsResults & Discussion ConclusionSSampleDescriptionPAPolyamide 6 naturalPAK1 90/10Polyamide filled with 10% Kaolinite K1PAK1 80/20Polyamide filled with 20% kaolinite K1PAK2 90/10Polyamide filled with 10% kaolinite K2PAK2 80/20Polyamide filled with 20% Kaolinite K2PAK1G 90/10Polyamide filled with10% modified kaolinite K1PAK1G 80/20Polyamide filled with 20% modified kaolinite K1CMGDCentre des MatriauxBoth fillers were incorporated from 20 to 60 % by weight and the following nomenclature was adopted throughout this presentation:5MethodsExtrusion/Injection molding220 250C

Cone CalorimeterIrradiance: 50kW/m2 HRR (heat release rate)TTI (time to ignition)THE (total heat evolved)

Mechanical TestsStress Strain (Zwick Z010)Instrom (4502)Rheological measurements at 240 C (ARES Rheometrics)

6IntroductionMaterials & MethodsResults & Discussion ConclusionSCMGDCentre des MatriauxCompositions were extruded using a twin-screw extruder. Square specimens were injection molded with dimensions of 100 100 4 mm. Processing conditions were: to avoid the degradation of the polymer.

Thermo oxidative degradation was carried out using ...at 10K/min under air from room temperature to 800C.

Epiradiateur test has been carried out on specimens of 50x50x4mm in order to get movies. In this test, a radiator of 500 W is placed at 25 mm over upper face of the specimen.

PCFC tests were carried out in....

The cone calorimeter is a standart apparatus used for fire retardancy tests. The sample of 100x100x4 mm isd placed horizontally on a balance and is irradiated from above (in this study 50kw*m-2 was used). Between the parameters obtained by cone calorimeter tests, in this study time to ignition, heat release rate and the peak of heat release rate will be focused. All samples were run in triplicate and average results were repported. Results from cone calorimeter are generally considered to be reproductible to +- 10.

Viscosity measurements were carried out in dynamic mode at 160 C using 0.05 % strain and a frequency ranging from 10-2s-1 to 102s-1 (ARES, Rheometric Scientific).67Cone Calorimeter Irr: 50kW*m-2

CompositepHRR (kW.m-2)TTI (s)THE (MJ.g-1)PA13007928.4PA/K1 90/1011705829.5PA/K1 80/207807029PA/K2 90/109907028.8PA/K2 80/209008229.1PA/K1G 90/106006029PA/K1G 80/204705029.1

CMGDCentre des MatriauxThe behavior of EVA is well known and is typical of a non charing polymer. For ATH composites, a significant reduction os obtained only at high loading, ca 50%. 7Rheology8IntroductionMaterials & MethodsResults & Discussion ConclusionS

CMGDCentre des MatriauxTo undesrtand the improved fire behavior observed, dynamical

Viscosity increase is expected to have important effects on gas bubbles: reduction on bubble rising velocity and bubble growth velocity. It should be noted that these measurements were not carried out in the same temperature as in cone calorimeter. But is there is a good relation between tan delta and pHRR for the tested composites.

It is interesting to note that even if the conditions used in this test are not the same of cone calorimeter, and, maybe, are far the real conditions, there is an interesting relation between tan delta and pHRR (showed here as a normalized tan delta which means that the value of the composite was divides by the value of the pure polymer).

The tangent of the phase angle the ratio of viscous modulus to elastic modulus and a useful quantifier of the presence and extent of elasticity in a fluid.

Um aumento do tan delta indica um aumento da proporao de resposta viscosa em relaao a resposta elastica do material.

8Mechanical Properties9CompositeYoungs modulus(MPa)Stress at Yield(MPa)Strain at Yield(%)A (m2)

PA3000 5583 1.535.5 0.1PA/K1 90/104126 9696 0.85 0.1PA/K1 80/204420 8899 0.84.6 0.124.4PA/K2 90/103904 106 63 3.151.9 0.1PA/K2 80/204300 6067 3.271.9 0.135

CMGDCentre des Matriaux9Mechanical Properties of Fibers10IntroductionMaterials & MethodsResults & Discussion ConclusionS

CompositeFiber diameter(m)Tensile Modulus (MPa)Stress at Yield (MPa)Stress at break(MPa)Strain at break(%)PA1287160829492133882436PA/K1 80/20130527566060181 144834PA/K2 80/2012711971364717514321CMGDCentre des Matriaux10ConclusionsThe incorporation of kaolinite in the PA6 has serious advantages :

Improved fire behaviorChanges in rheological behavior limiting mass transferG x pHRR

Improvement of mechanical propertiesPresence of agglomerates11IntroductionMaterials & MethodsResults & Discussion ConclusionSCMGDCentre des MatriauxThe presence of the kaolinite particles slow mass tranfer from the degrading polymer to vapour phase and insulate the material from heat source.11Thank you for your attention!12CMGDCentre des Matriaux