Effect of chain length on the conductivity of polyacetylene. Potential dependence of the conductivity of a series of polyenes prepared by a living polymerization method

1992 ◽  
Vol 4 (6) ◽  
pp. 1388-1395 ◽  
Author(s):  
L. Y. Park ◽  
D. Ofer ◽  
T. J. Gardner ◽  
R. R. Schrock ◽  
M. S. Wrighton
2021 ◽  
Author(s):  
Subhajit Pal ◽  
Dinh Phuong Trinh Nguyen ◽  
Angélique Molliet ◽  
Mahshid Alizadeh ◽  
Aurélien Crochet ◽  
...  

2018 ◽  
Vol 39 (20) ◽  
pp. 1800479 ◽  
Author(s):  
Xiaofeng Guo ◽  
Bonnie Choi ◽  
Anchao Feng ◽  
San H. Thang

2021 ◽  
Author(s):  
Han Cao ◽  
Ruoyu Zhang ◽  
zhou zhou ◽  
Shunjie Liu ◽  
Youhua Tao ◽  
...  

Quantitative transformation of CO2 can greatly elevate the sustainability impact of CO2 chemical utilization, but it is formidably challenging due to the sluggish kinetics requiring overwhelmingly excess usage of CO2. Here, we report an on demand CO2 transformation by a switch polymerization method, that is, all reactants including CO2 are fully converted without any by-product, generating tailor-made poly(ether carbonate) polyols (CO2-polyols) whose composition and chain length exactly correspond to the feed of CO2, epoxide and diacid. This is the first time for CO2 as a countable monomer which is in most cases obscurely considered as “pressure condition”. Studies on the kinetics rate law and the activation parameters of key intermediates disclose that it is the multisite cooperativity from metallic oligomer catalyst that facilitates quantitative insertion of CO2 into polymer backbone without adverse backbiting throughout the polymerization. Hence, this work not only introduces the conception of quantitative CO2 transformation, but engineers exquisite CO2-based polymer which is rarely achieved.<br>


2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Jinhui Feng ◽  
Fuyan He ◽  
Zhizhou Yang ◽  
Jinshui Yao

AbstractAs a green, safe and eco-friendly solvent, ionic liquids (ILs) have been widely used in organic syntheses. In this paper, polyamide-imides (PAIs) based on different chain length of amino acids were synthesized by two methods, i.e. in the presence of tetrabutyl ammonium bromide (TBAB) as IL and via conventional polycondensation. The obtained results have been compared. It was confirmed that by the polymerization method in the IL, the PAIs can get higher molecular weight and viscosity and better heat resistance and crystallinity after annealing treatment. All polymers showed higher tensile strength (122–134 MPa) and tensile modulus (2.4–3.0 GPa). Among them, the molecular weight of PAIs based on glycine was characterized by gel permeation chromatography.


2021 ◽  
Author(s):  
Han Cao ◽  
Ruoyu Zhang ◽  
zhou zhou ◽  
Shunjie Liu ◽  
Youhua Tao ◽  
...  

Quantitative transformation of CO2 can greatly elevate the sustainability impact of CO2 chemical utilization, but it is formidably challenging due to the sluggish kinetics requiring overwhelmingly excess usage of CO2. Here, we report an on demand CO2 transformation by a switch polymerization method, that is, all reactants including CO2 are fully converted without any by-product, generating tailor-made poly(ether carbonate) polyols (CO2-polyols) whose composition and chain length exactly correspond to the feed of CO2, epoxide and diacid. This is the first time for CO2 as a countable monomer which is in most cases obscurely considered as “pressure condition”. Studies on the kinetics rate law and the activation parameters of key intermediates disclose that it is the multisite cooperativity from metallic oligomer catalyst that facilitates quantitative insertion of CO2 into polymer backbone without adverse backbiting throughout the polymerization. Hence, this work not only introduces the conception of quantitative CO2 transformation, but engineers exquisite CO2-based polymer which is rarely achieved.<br>


2001 ◽  
Vol 120 (5) ◽  
pp. A710-A710
Author(s):  
S LAL ◽  
J MCLAUGHLIN ◽  
O NIAZ ◽  
G DOCKRAY ◽  
A VARRO ◽  
...  

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