scholarly journals Molecular-Weight Dependence of the Formation of Extended-Chain Crystals in Polyethylene under High Pressure

1979 ◽  
Vol 11 (7) ◽  
pp. 551-558
Author(s):  
Shuichi Sawada ◽  
Ken Kato ◽  
Takuhei Nose
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
Molecular Weight Dependence ◽  
Extended Chain

scholarly journals Molecular Weight Dependence of the viscoisity of Polydimethylsiloxane under high Pressure

1971 ◽  
Vol 28 (319) ◽  
pp. 830-834,934
Author(s):  
Sadahide Ogihara ◽  
Takeshi Takaki ◽  
Hiroshige Sasaki
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
Molecular Weight Dependence

scholarly journals Molecular Weight Dependence of Primary Nucleation Rate of Polyethylene I. An Extended Chain Single Crystal

1999 ◽  
Vol 31 (9) ◽  
pp. 749-758 ◽  
Author(s):  
Mutsuo Nishi ◽  
Masamichi Hikosaka ◽  
Swapan Kumer Ghosh ◽  
Akihiko Toda ◽  
Koji Yamada
Keyword(s):  
Molecular Weight ◽  
Single Crystal ◽  
Nucleation Rate ◽  
Primary Nucleation ◽  
Molecular Weight Dependence ◽  
Extended Chain

Molecular weight dependence of lateral growth rate of polyethylene (I) — an extended chain single crystal

Polymer ◽  
1998 ◽  
Vol 39 (8-9) ◽  
pp. 1591-1596 ◽  
Author(s):  
Mutsuo Nishi ◽  
Masamichi Hikosaka ◽  
Akihiko Toda ◽  
Masato Takahashi
Keyword(s):  
Molecular Weight ◽  
Growth Rate ◽  
Single Crystal ◽  
Lateral Growth ◽  
Molecular Weight Dependence ◽  
Extended Chain ◽  
Lateral Growth Rate

The High Pressure Rheology of Mixtures

2004 ◽  
Vol 126 (4) ◽  
pp. 697-702 ◽  
Author(s):  
Scott Bair
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
Binary Systems ◽  
Viscosity Coefficient ◽  
Shear Thinning ◽  
Newtonian Viscosity ◽  
Double Shear ◽  
Ideal Mixing ◽  
Viscosity Behavior ◽  
Single Flow

The Newtonian mixing rules for several binary systems have been experimentally investigated. Some systems show non-ideal mixing response and for some systems the non-ideal response is pressure-dependent, yielding an opportunity for manipulation of the pressure-viscosity behavior to advantage. The mixing of differing molecular weight “straight cuts” can produce very different pressure-viscosity response. This behavior underscores the difficulty in predicting the pressure-viscosity coefficient based upon chemical structure and ambient viscosity since the molecular weight distribution is also important, but it also provides another opportunity to control the high-pressure response by blending. The first experimental observation of double shear-thinning within a single flow curve is reported. Blending then provides the capability of adjusting not only the Newtonian viscosity but also the non-Newtonian shear-thinning response as well.

The Use of Novel F-RAFT Agents in High Temperature and High Pressure Ethene Polymerization: Can Control be Achieved?

2007 ◽  
Vol 60 (10) ◽  
pp. 788 ◽  
Author(s):  
Markus Busch ◽  
Marion Roth ◽  
Martina H. Stenzel ◽  
Thomas P. Davis ◽  
Christopher Barner-Kowollik
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
High Temperature ◽  
Degree Of Polymerization ◽  
Molecular Weight Distributions ◽  
High Pressure High Temperature ◽  
Reversible Addition ◽  
Weight Distributions ◽  
Raft Agent ◽  
Initial Results

Simulations are employed to establish the feasibility of achieving controlled/living ethene polymerizations. Such simulations indicate that reversible addition–fragmentation chain transfer (RAFT) agents carrying a fluorine Z group may be suitable to establish control in high-pressure high-temperature ethene polymerizations. Based on these simulations, specific fluorine (F-RAFT) agents have been designed and tested. The initial results are promising and indicate that it may indeed be possible to achieve molecular weight distributions with a polydispersity being significantly lower than that observed in the conventional free radical process. In our initial trials presented here (using the F-RAFT agent isopropylfluorodithioformate), a correlation between the degree of polymerization and conversion can indeed be observed. Both the lowered polydispersity and the linear correlation between molecular weight and conversion indicate that control may in principle be possible.

Molecular weight dependence of the conformational phase transition and electroluminescence of diarylpolysilane diodes

2000 ◽  
Vol 88 (6) ◽  
pp. 3408-3413 ◽  
Author(s):  
Satoshi Hoshino ◽  
Kazuaki Furukawa ◽  
Keisuke Ebata ◽  
Ingo Breyl ◽  
Hiroyuki Suzuki
Keyword(s):  
Phase Transition ◽  
Molecular Weight ◽  
Molecular Weight Dependence
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