Free-Volume and Tensile Properties of Glass Fibre Reinforced Polyamide 6 Composites

The tensile properties and free volume of commercially available modified polyamid 6 and polyamid 6 composites with 15 and 30 wt% of glass fibre were the subject of the studies. The tensile test allowed us to obtain the stress-strain curves and determine the tensile properties of the polyamid 6 samples. The positron lifetime measurements were performed for the samples before the test and for the samples in the vicinity of the break after they failed. The composites exhibited slightly lower values of the ortho-positronium lifetime and therefore smaller size of the local free volumes in comparison to polyamid 6 without reinforcement. The analysis of the positron lifetime spectra indicated size distribution of the free volume. The initially narrower distributions for the composite samples became broader as a result of the deformation. The deformation caused also increase of the ortho-positronium intensity in the obtained positron lifetime spectra.