Effect of Chain Straightening on Plateau Modulus and Entanglement Molecular Weight of Ni-diimine Poly(1-hexene)s

✍ Scribed by Zhibin Ye; Wei Feng; Shiping Zhu; Qiang Yu

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 153 KB
• Volume: 27
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200600098

✦ Synopsis

Abstract

Summary: In this communication, we report the first rheological study on the chain‐straightened Ni‐diimine poly(1‐hexene)s and investigate the unique effect of chain straightening on plateau modulus and entanglement molecular weight of this series of polymers. Two Ni‐diimine poly(1‐hexene) samples having different levels of chain straightening were prepared with a chain‐walking Ni‐diimine catalyst, (ArNC(An)C(An)NAr)NiBr~2~ (An = acenaphthene, Ar = 2,6‐(i‐Pr)~2~C~6~H~3~) at two different temperatures. Rheological analyses show that the chain‐straightened polymers exhibit significantly enhanced plateau modulus and reduced entanglement molecular weight compared to regular poly(1‐hexene)s by metallocene catalysis. Such an effect becomes more pronounced with an increase in the level of chain straightening.

Loss moduli G″(ω) versus reduced angular frequency in a linear, natural logarithm plot for the three polymers at the reference temperature of 100 °C.

imageLoss moduli G″(ω) versus reduced angular frequency in a linear, natural logarithm plot for the three polymers at the reference temperature of 100 °C.