Mechanical Properties of in-situ fiber reinforced Composites from Blends Containing Polyethylene with Poly-caprolactam

摘要

In-situ fiber reinforced composites was prepared by blending low-density polyehtylene (LDPE) and poly-caprolactam (PCL). In this study, the LDPE and the PCL were compounded and fabricated by single screw extruder equipped with slit type die. The dispersive phase deform to fiber and effectively reinforce the matrix resin. The extrusion products were extracted using chloroform by a soxhlet extractor, and then the residue and the extract were analyzed by means of FT-IR spectroscopy. Especially, the residue was observed by scanning electron microscope (SEM). Tensile test was carried out for each blend products. The fiber component and the matrix could be determinated by fT-IR analyses. The fiber reinforcements which is like fiber bundles were aligned along the flow direction at core area; on the other hand the fiber reinforcements were network structure at the surface area and entangled with each other. The tensile moduli of blend sheets were over the value that estiamted from the law of mixture. This was due to the high aspect ratio of these fiber reinforcements and physical interaction such as entanglement. It is cleared that the fiber componetn effectively reinforced the LDPE/PCL blend product. The solubility parameters of these polymers are so different and these polymers could not be adhered after heating over these melting points, so that the interfacial interaction was poor. If he poor interfacial itneraction is improved, the mechanical properties will be more excellent.