Regulation of tectonic sequence in chain-folding-directed monodisperse isomeric oligomers precisely tailored by Ugi–hydrosilylation orthogonal cycles

2021 ◽  
Author(s):  
Chao Li ◽  
Li Han ◽  
Xiping Chen ◽  
Xinyu Bao ◽  
Qi Sun ◽  
...  
Keyword(s):  
Chain Folding ◽  
Tectonic Sequence

Monodisperse discrete oligomers with tailored sequence of linkages within the backbones, which has been defined as tectonic sequence, were precisely constructed through Ugi four-component reactions (Ugi-4CRs) coupled to hydrosilylations orthogonal...

A New Defect in Polyethylene Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 70-71
Author(s):  
E. L. Thomas ◽  
S. L. Sass
Keyword(s):  
Single Crystals ◽  
Screw Dislocation ◽  
Small Distance ◽  
Dipole Model ◽  
Dislocation Dipole ◽  
Chain Folding ◽  
Black And White ◽  
Polymer Crystal ◽  
Different Types

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.

High-resolution gold labeling

1993 ◽  
Vol 51 ◽  
pp. 330-331
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya ◽  
Kyra Carbone ◽  
Martha Simon ◽  
Beth Lin ◽  
...  
Keyword(s):  
Dihydrofolate Reductase ◽  
Polypeptide Chain ◽  
External Surface ◽  
Gold Cluster ◽  
Macromolecular Complex ◽  
Gold Compound ◽  
Central Cavity ◽  
Chain Folding ◽  
E Coli ◽  
Chaperonin Groel

A recently developed 1.4 nm gold cluster has been found to be useful in labeling macromolecular sites to 1-3 nm resolution. The gold compound is organically derivatized to contain a monofunctional arm for covalent linking to biomolecules. This may be used to mark a specific site on a structure, or to first label a component and then reassemble a multicomponent macromolecular complex. Two examples are given here: the chaperonin groEL and ribosomes.Chaperonins are essential oligomeric complexes that mediate nascent polypeptide chain folding to produce active proteins. The E. coli chaperonin, groEL, has two stacked rings with a central hole ∽6 nm in diameter. The protein dihydrofolate reductase (DHFR) is a small protein that has been used in chain folding experiments, and serves as a model substrate for groEL. By labeling the DHFR with gold, its position with respect to the groEL complex can be followed. In particular, it was sought to determine if DHFR refolds on the external surface of the groEL complex, or whether it interacts in the central cavity.

Shrinkage and chain folding in drawn poly(ethylene terephthalate) fibres

Polymer ◽  
1974 ◽  
Vol 15 (5) ◽  
pp. 277-282 ◽  
Author(s):  
M.P.W. Wilson
Keyword(s):  
Ethylene Terephthalate ◽  
Chain Folding ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Regime III crystallization in melt-crystallized polymers: The variable cluster model of chain folding

Polymer ◽  
1983 ◽  
Vol 24 (1) ◽  
pp. 3-26 ◽  
Author(s):  
John D. Hoffman
Keyword(s):  
Cluster Model ◽  
Chain Folding ◽  
Variable Cluster

Chain Folding in Crystallizable Block Copolymers

1997 ◽  
Vol 30 (6) ◽  
pp. 1723-1727 ◽  
Author(s):  
Anthony J. Ryan ◽  
J. Patrick A. Fairclough ◽  
Ian W. Hamley ◽  
Shao-Min Mai ◽  
Colin Booth
Keyword(s):  
Block Copolymers ◽  
Chain Folding

Polymer decoration study in chain folding behavior of solution-grown poly(ethylene oxide) crystals

1995 ◽  
Vol 33 (13) ◽  
pp. 1851-1855 ◽  
Author(s):  
Jianhua Chen ◽  
Stephen Z. D. Cheng ◽  
Scott S. Wu ◽  
Bernard Lotz ◽  
Jean-Claude Wittmann
Keyword(s):  
Ethylene Oxide ◽  
Chain Folding ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Oxide Crystals

Elucidation of the Chain-Folding Structure of a Semicrystalline Polymer in Single Crystals by Solid-State NMR

2014 ◽  
Vol 3 (6) ◽  
pp. 556-559 ◽  
Author(s):  
You-lee Hong ◽  
Toshikazu Miyoshi
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Solid State Nmr ◽  
Semicrystalline Polymer ◽  
Chain Folding ◽  
Folding Structure
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