Reactivity of Poly(alkoxycarbonylmethylene)s under Basic Conditions: Alkylation of Main Chain Carbon Atoms via Ketene Silyl Acetal-type Intermediate and Cleavage of Carbon–carbon Main Chain

2021 ◽  
Author(s):  
Hiroaki Shimomoto ◽  
Shogo Tsunematsu ◽  
Tomomichi Itoh ◽  
Eiji Ihara
Keyword(s):  
Main Chain ◽  
Lithium Diisopropylamide ◽  
Type Intermediate

The reactivities of poly(alkoxycarbonylmethylene)s under basic conditions are described. The reactions of poly(ethoxycarbonylmethylene) (polyEDA’) and poly(benzyloxycarbonylmethylene) (polyBDA’) with a mixture of lithium diisopropylamide and trimethylsilyl chloride transformed a part of...

Temperature-dependent photoluminescence from MEH-PPV and MEH-OPPV containing oxadiazole in the main chain

2006 ◽  
Vol 84 (1-2) ◽  
pp. 203-206 ◽  
Author(s):  
F. Kong ◽  
X.L. Wu ◽  
G.S. Huang ◽  
R.K. Yuan ◽  
C.Z. Yang ◽  
...  
Keyword(s):  
Main Chain ◽  
Temperature Dependent ◽  
Temperature Dependent Photoluminescence

scholarly journals Internal constraints and arrested relaxation in main-chain nematic elastomers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Takuya Ohzono ◽  
Kaoru Katoh ◽  
Hiroyuki Minamikawa ◽  
Mohand O. Saed ◽  
Eugene M. Terentjev
Keyword(s):  
Mechanical Properties ◽  
Main Chain ◽  
Polymer Networks ◽  
Nematic Order ◽  
Nematic Elastomers ◽  
Nematic Director ◽  
Highly Nonlinear ◽  
Nonlinear Mechanical ◽  
Liquid Crystal Elastomers ◽  
Memory Applications

AbstractNematic liquid crystal elastomers (N-LCE) exhibit intriguing mechanical properties, such as reversible actuation and soft elasticity, which manifests as a wide plateau of low nearly-constant stress upon stretching. N-LCE also have a characteristically slow stress relaxation, which sometimes prevents their shape recovery. To understand how the inherent nematic order retards and arrests the equilibration, here we examine hysteretic stress-strain characteristics in a series of specifically designed main-chain N-LCE, investigating both macroscopic mechanical properties and the microscopic nematic director distribution under applied strains. The hysteretic features are attributed to the dynamics of thermodynamically unfavoured hairpins, the sharp folds on anisotropic polymer strands, the creation and transition of which are restricted by the nematic order. These findings provide a new avenue for tuning the hysteretic nature of N-LCE at both macro- and microscopic levels via different designs of polymer networks, toward materials with highly nonlinear mechanical properties and shape-memory applications.

Synthesis of polyethers containing cyclodipeptide moiety in the main chain

2001 ◽  
Vol 39 (6) ◽  
pp. 927-933 ◽  
Author(s):  
Tadayuki Kunisaki ◽  
Kimiko Kawai ◽  
Keiko Hirohata ◽  
Kazuhiro Minami ◽  
Koichi Kondo
Keyword(s):  
Main Chain

Main-Chain-Type 8-Quinolinol Polymers:  Synthesis, Optical Properties, and Complex Formation with Metals

2008 ◽  
Vol 41 (5) ◽  
pp. 1654-1662 ◽  
Author(s):  
Takayuki Iijima ◽  
Shin-ichi Kuroda ◽  
Takakazu Yamamoto
Keyword(s):  
Optical Properties ◽  
Complex Formation ◽  
Main Chain ◽  
Chain Type
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