A comparison of the flow behavior of linear polyethylene, poly(butylene terephthalate), and poly(ethylene terephthalate)

✍ Scribed by Edwin Boudreaux Jr.; John A. Cuculo

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: English
• Weight: 1022 KB
• Volume: 27
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1982.070270131

✦ Synopsis

The viscous and elastic properties of linear high density polyethylene (HDPE), poly(buty1ene terephthalate) (PBT), and poly(ethy1ene terephthalate) (PET) are investigated using an Instron capillary rheometer and the Philippoff-Gaskins-Bagley analysis. The viscous properties studied are the shear viscosity and the constant shear rate activation energy and the elastic properties studied are the entrance pressure drop and the end correction. The variables are shear rate and temperature. The order of decreasing viscosity is HDPE > PET > PBT; the order of decreasing activation energy is PB > PET > HDPE the order of decreasing entrance pressure drop is HDPE > PET > PBT; and the order of decreasing end correction is PBT > PET > HDPE. As temperature increases, both viscosity and entrance pressure drop decrease. The observed behavior is discussed in terms of the difference in number of terephthalic acid moities in the polymer chains and in terms of oligomer plasticization.