Melt Spinning and Drawing of Polyethylene Nanocomposite Fibers with Organically Modified Hydrotalcite

摘要

Fibers of high density polyethylene (HDPE)/organically modified hydrotalcite (LDH) were produced by melt intercalation in a two-step process consisting of twin-screw extrusion and hot drawing. The optimum drawing temperature was 125oC at which the draw ratios up to 20 could be achieved. XRD analysis revealed intercalation with a high degree of exfoliation for the composites with 1-2 of LDH. Higher thermal stability of nanofilled fibers was confirmed by TGA analysis. DSC data indicated that dispersed LDH particles act as a nucleating agent. Crystallization kinetics of the HDPE matrix in the composite fibers is characterized by two transition temperatures, that is, for Regimes I/II at 123oC and for Regimes II/III ranging between 114-119oC as a function of the nanocomposite composition. Fibers with 1-2 of LDH show for the drawing ratios up to 15 a higher elastic modulus, 9.0-9.3 GPa (with respect to 8.0 GPa of the neat HDPE), maintain tensile strength of 0.8 GPa and deformation at break of 20-25.