scholarly journals Cyclohexyl-substituted poly(phosphonate)-copolymers with adjustable glass transition temperatures

2016 ◽  
Vol 7 (17) ◽  
pp. 2934-2937 ◽  
Author(s):  
Thomas Wolf ◽  
Johannes Naß ◽  
Frederik R. Wurm
Keyword(s):  
Glass Transition ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Anionic Ring ◽  
Poly Ethylene

2-Cyclohexyl-2-oxo-1,3,2-dioxaphospholane (cyHexPPn), a new monomer for the anionic ring-opening polymerization to poly(ethylene alkyl phosphonate)s is presented.

Functionalized Polyesters via Stereoselective Electrochemical Ring-Opening Polymerization of O-Carboxyanhydrides

2020 ◽  
Author(s):  
Yongliang Zhong ◽  
quanyou feng ◽  
xiaoqian wang ◽  
jia chen ◽  
wenjun cai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Catalytic System ◽  
Ring Opening ◽  
Electrical Current ◽  
Ring Opening Polymerization ◽  
Glass Transition Temperatures ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Ring-opening polymerization is used to prepare polyesters with precisely controlled molecular weights, molecular weight distributions, and tacticities. Herein, we report a newly developed Co/Zn catalytic system that can be activated by an electrical current to mediate efficient ring-opening polymerization of enantiopure <i>O</i>-carboxyanhydrides, allowing for the synthesis of isotactic functionalized polyesters with high molecular weights (>140 kDa) and narrow molecular weight distributions (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.1). We also demonstrate that these catalysts can be used for stereoselective ring-opening polymerization of racemic <i>O</i>-carboxyanhydrides to synthesize syndiotactic or stereoblock copolymers with different glass transition temperatures compared with their atactic counterparts.

Synthesis and Properties of New Triphenylamine-Containing Aromatic Polyimides Based on N,N′-Bis(4-Aminophenyl)-N,N′-Diphenyl-4,4′-Biphenyldiamine

2003 ◽  
Vol 15 (3) ◽  
pp. 281-290 ◽  
Author(s):  
Yoshio Imai ◽  
Mina Ishida ◽  
Masa-Aki Kakimoto
Keyword(s):  
Weight Loss ◽  
Glass Transition ◽  
Tensile Properties ◽  
Organic Solvents ◽  
Ring Opening ◽  
Aromatic Diamine ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Aromatic Polyimides ◽  
Step Procedure

A new aromatic diamine monomer, N,N′-bis(4-aminophenyl)-N,N′-diphenyl-4,4′-biphenyldiamine, was first synthesized in two steps by the condensation of N,N′-diphenyl-4,4′-biphenyldiamine with 4-fluoronitrobenzene, followed by reduction. New triphenylamine-containing aromatic polyimides having inherent viscosities of 0.67-0.91 dl g−1 were synthesized from the aromatic diamine and various aromatic tetracarboxylic dianhydrides by the conventional two-step procedure that included ring-opening polyaddition giving precursor polyamic acids and subsequent thermal cyclodehydration. Most of the aromatic polyimides were soluble on heating in organic solvents such as dimethylacetamide, m-cresol, pyridine, and chloroform, and gave flexible and tough films with good tensile properties. The glass transition temperatures and 10% weight loss temperatures of the polyimides were in the range of 293-361 and 565-595 °C, respectively, in nitrogen.

scholarly journals Functionalized Polyesters via Stereoselective Electrochemical Ring-Opening Polymerization of O-Carboxyanhydrides

2020 ◽  
Author(s):  
Yongliang Zhong ◽  
quanyou feng ◽  
xiaoqian wang ◽  
jia chen ◽  
wenjun cai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Catalytic System ◽  
Ring Opening ◽  
Electrical Current ◽  
Ring Opening Polymerization ◽  
Glass Transition Temperatures ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Ring-opening polymerization is used to prepare polyesters with precisely controlled molecular weights, molecular weight distributions, and tacticities. Herein, we report a newly developed Co/Zn catalytic system that can be activated by an electrical current to mediate efficient ring-opening polymerization of enantiopure <i>O</i>-carboxyanhydrides, allowing for the synthesis of isotactic functionalized polyesters with high molecular weights (>140 kDa) and narrow molecular weight distributions (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> < 1.1). We also demonstrate that these catalysts can be used for stereoselective ring-opening polymerization of racemic <i>O</i>-carboxyanhydrides to synthesize syndiotactic or stereoblock copolymers with different glass transition temperatures compared with their atactic counterparts.

scholarly journals Cerium Salts: An Efficient Curing Catalyst for Benzoxazine Based Coatings

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 415 ◽  
Author(s):  
Tao Zhang ◽  
Leïla Bonnaud ◽  
Jean-Marie Raquez ◽  
Marc Poorteman ◽  
Marjorie Olivier ◽  
...  
Keyword(s):  
Glass Transition ◽  
Ring Opening ◽  
Catalytic Effect ◽  
Ring Opening Polymerization ◽  
Curing Temperature ◽  
Energy Dispersive ◽  
Glass Transition Temperatures ◽  
X Ray ◽  
Catalytic Activities ◽  
Ft Ir

The effect of three different cerium salts (Ce(NO3)3·6H2O, CeCl3·7H2O and Ce(OOCCH3)3·5H2O) on the ring-opening polymerization (ROP) of a model diamine-based benzoxazine (4EP-pPDA) was investigated. With the incorporation of the cerium salts, the curing temperature of 4EP-pPDA is reduced substantially, and the glass transition temperatures of the resulting networks are increased significantly. The three cerium salts exhibit different catalytic activities, which were analyzed by FT-IR, NMR, and energy-dispersive X-ray (EDX). Ce(NO3)3·6H2O was found to exhibit the best catalytic effect, which seems to be related to its better dispersibility within 4EP-pPDA benzoxazine precursors.

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