Melt strength and extensional viscosity of low-density polyethylene and poly(butylene succinate) blends using a melt-spinning technique

摘要

The melt strength (MS) and extensional viscosity of low-density polyethylene/poly(butylene succinate) (LDPE/PBS) blends were measured using a melt-spinning technique to investigate the effects of extrusion conditions and mixing ratios on the extensional flow. The experimental results indicated that maximal extensional length and MS of the LDPE/PBS blends decreased with an increase of PBS content. The response of the MS to the extrusion rate depended on the components of the blends. The extensional viscosity of the LDPE/PBS blends decreased with the increases of PBS content, extrusion rate, and extensional strain rate. Extensional master curves were suitable for the LDPE/PBS blends, and the scaling factor decreased with the increase of extrusion rate according to a power law. When the PBS content was not more than 40%, with the further increase of the PBS content, the sensitivity of the scaling factor to the extrusion rate decreased. However, when the PBS content was 60%, the sensitivity of the scaling factor to the extrusion rate increased, and was close to the sensitivity of the LDPE melt. Based on the extensional master curve and the back propagation (BP) neural network model, predicted extensional viscosities were compared with the experimental results.