Anomalous rheological response for binary blends of linear polyethylene and long-chain branched polyethylene

2007 ◽  
Vol 26 (3) ◽  
pp. 173-181 ◽  
Author(s):  
Naoya Mieda ◽  
Masayuki Yamaguchi
Keyword(s):  
Binary Blends ◽  
Linear Polyethylene ◽  
Branched Polyethylene ◽  
Rheological Response ◽  
Long Chain

Synthesis of long-chain-branched polyethylene by ethylene homopolymerization with a novel nickel(II) ?-diimine catalyst

2005 ◽  
Vol 43 (7) ◽  
pp. 1325-1330 ◽  
Author(s):  
Hao Zou ◽  
Fang Ming Zhu ◽  
Qing Wu ◽  
Jiao Yan Ai ◽  
Shang An Lin
Keyword(s):  
Branched Polyethylene ◽  
Long Chain

Effect of shear history on flow instability at capillary extrusion for long-chain branched polyethylene

2011 ◽  
Vol 124 (1) ◽  
pp. 429-435 ◽  
Author(s):  
Siriprumpoonthum Monchai ◽  
Naoya Mieda ◽  
Vu Anh Doan ◽  
Shogo Nobukawa ◽  
Masayuki Yamaguchi
Keyword(s):  
Flow Instability ◽  
Branched Polyethylene ◽  
Capillary Extrusion ◽  
Long Chain ◽  
Shear History

Diffusion in molten polymers: the influence of hydrostatic pressure

1982 ◽  
Vol 383 (1784) ◽  
pp. 1-14 ◽  
Keyword(s):  
Hydrostatic Pressure ◽  
Activation Volume ◽  
Linear Polyethylene ◽  
Chain Molecules ◽  
A Value ◽  
Diffusion Studies ◽  
The Matrix ◽  
Molten Polymers ◽  
Effect Of Hydrostatic Pressure ◽  
Long Chain

This paper describes an experimental study of the effect of hydrostatic pressure on the diffusion of linear hydrocarbons through molten polyethylene and polypropylene. The diffusants range in length from 20 to 260 carbons and are suitably tagged for identification by infrared spectroscopy. The results show that the diffusion coefficient D is reduced by the pressure p and the behaviour may be described by a relation of the form D = D 0 e - pV / kT , where V is the activation volume. For hydrocarbons ranging in length from 20 to 260 carbons diffusing through both branched and linear polyethylene, V has a value lying between about 40 and 90 Å 3 (1 Å 3 = 10 -30 m 3 ). Diffusion through polypropylene involves a small but significant increase in V . Similarly the incorporation of a bulky group in the middle of a linear hydrocarbon produces some increase in V . However, the main conclusion is that the activation volume bears no relation to the size of the diffusant: it corresponds to the volume of only three or four carbons in the chain. These results and the earlier diffusion studies of Klein & Briscoe (1976, 1979) suggest that diffusion of long chain molecules through a molten polymer proceeds by a process of reptation in which the fine scale mechanism involves cooperative rotations or crankshaft motions of both the diffusant and the matrix.

Sign in / Sign up

Export Citation Format

Share Document