CONTRIBUTION TO STUDY OF THE EFFECTS OF ADDITION OF PLASTICIZER AND OF AGEING ON THE VISCOELASTIC PROPERTIES OF POLYAMIDE

The purpose of this study is to obtain some information about the viscoelastic properties of the material and to see the effect of the addition of plasticizer on these properties. In particular, we try to study the loss of plasticizer, caused by ageing under conditions of utilization, on the properties of material at the neighborhood of vitreous transition. Using a viscoelastimeter, the study of a polyamide-11 (PA11) at the neighborhood of its temperature of vitreous transition Tv has shown that the increase of the plasticizer rate clearly improves the properties of the material by decreasing its Tv temperature. The comparison of the curves giving the modulus of elasticity E' of the various samples showed that the mechanical properties of the material improve with the increase of the concentration of plasticizer, but ageing reduces this improvement by causing the loss of plasticizer, thus, the temperature range of utilization of material is reduced.