Effect of Short Chain Branching of LDPE on its Miscibility with Linear HDPE

✍ Scribed by Tayyab Hameed; Ibnelwaleed A. Hussein

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 129 KB
• Volume: 289
• Category: Article
• ISSN: 1438-7492
• DOI: 10.1002/mame.200300173

✦ Synopsis

Abstract

Summary: The influences of short chain branching (SBC) on the melt miscibility of low‐density polyethylene (LDPE) with linear high‐density polyethylene (HDPE) were investigated by rheological methods. Two LDPE resins with different branch contents were blended with the same linear HDPE. Dynamic and steady shear measurements were carried out using a Rheometrics ARES rheometer at 190 °C. The rheology of the low‐SCB LDPE (9 CH~3~/1 000 C) blends with HDPE can be predicted by the linear additivity rule. Hence, blends were suggested to be completely miscible at all compositions. However, blends of the high branch content LDPE (SCB = 19 CH~3~/1 000 C) were completely immiscible. Also, the different viscous and elastic properties of all the immiscible blends were much higher than the corresponding values for the more viscous and elastic blend component. The ratio of interfacial tension to droplet radius was estimated from Scholz et al. model as ≈1 500 N · m^−2^. The level of SCB in LDPE was found to have a strong influence on its miscibility with linear HDPE.

Cole‐Cole plot for blends of LDPE1 with HDPE.

magnified imageCole‐Cole plot for blends of LDPE1 with HDPE.