Ring-opening copolymerization of ethylene carbonate and ɛ-caprolactone catalyzed by neodymium tris(2,6-di-tert-butyl-4-methylphenolate): Synthesis, characterization, and dynamic mechanic analysis

2008 ◽  
Vol 46 (12) ◽  
pp. 4050-4055 ◽  
Author(s):  
Feng Chen ◽  
Weipu Zhu ◽  
Ning Xu ◽  
Zhiquan Shen
Keyword(s):  
Ring Opening ◽  
Ethylene Carbonate ◽  
Mechanic Analysis ◽  
Tert Butyl ◽  
Dynamic Mechanic Analysis

Novel Biodegradable Polyurethane Foams Synthesized via Ring-Opening Oligomerization of Ethylene Carbonate Initiated / Catalyzed by Propylene Glycol / [bmim]Cl-(SnCl2) System

2010 ◽  
Vol 146-147 ◽  
pp. 1451-1457
Author(s):  
Jian Cheng Zhou ◽  
Ling Cheng ◽  
Dong Fang Wu
Keyword(s):  
Propylene Glycol ◽  
Ring Opening ◽  
Ethylene Carbonate ◽  
Polyurethane Foams ◽  
Lewis Acidity ◽  
Soil Burial ◽  
Molecular Weights ◽  
Chain Cleavage ◽  
Biodegradable Polyurethane ◽  
Catalytic Performances

Poly ether-carbonate diols were synthesized by ring-opening oligomerization of ethylene carbonate (EC) initiated/catalyzed by propylene glycol/[bmim]Cl-(SnCl2) system. It was shown that the oligomerization was accompanied with decarboxylation and chain cleavage. The stronger the lewis acidity of ionic liquid, the better the catalytic performances. The biogradability of the polyurethane foams which was prepared by poly ether-carbonate diols (or common polyether polyos ZS-4110) and diphenylmethane diisocyanate (MDI) was determined by soil burial and found to be influenced by the content of carbonate unit, molecular weights and the hydroxyl value of polyols respectively. Poly ether-carbonate diols can reduce the amount of MDI in synthesis of polyurethane foams.

scholarly journals Ring-opening polymerization of ethylene carbonate: comprehensive structural elucidation by 1D & 2D-NMR techniques, and selectivity analysis

RSC Advances ◽  
2017 ◽  
Vol 7 (19) ◽  
pp. 11786-11795 ◽  
Author(s):  
Rubina Abdul-Karim ◽  
Abdul Hameed ◽  
Muhammad Imran Malik
Keyword(s):  
Ring Opening ◽  
Ethylene Carbonate ◽  
2D Nmr ◽  
Ring Opening Polymerization ◽  
Structural Elucidation ◽  
Nmr Techniques ◽  
Poly Ethylene

Meticulous structural elucidation and selectivity analysis of poly(ethylene ether carbonate) by multi-dimensional NMR.

scholarly journals Synthesis of poly(γ-tert-butyl L-glutamate): influence of polymerization conditions

2019 ◽  
Vol 16 (3) ◽  
pp. 25
Author(s):  
Phung Thi Thuy Dung ◽  
Nguyen Thi Le Thu
Keyword(s):  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Attenuated Total Reflection ◽  
Resonance Spectroscopy ◽  
Reaction Conditions ◽  
Tert Butyl ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Polymerization Conditions

This work presents the synthesis and characterization of poly(γ-tert-butyl L-glutamate) (PtBuLG) via a living ring-opening polymerization procedure of γ-tert-butyl L-glutamate N-carboxyanhydride (tBuLG-NCA). The reaction conditions were investigated to optimize the polymerization yield and molecular weight polydispersity. The synthesized PtBuLG was characterized using nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and attenuated total reflection-Fourier transform infrared (ATR FT-IR. Finally, hydrolysis of PtBuLG resulted in poly(L-glutamic acid) (PLGA).

Record-Breaking Steric Crowding in Trialkylamines Prepared by Oxidative Ring Opening

Synthesis ◽  
2020 ◽  
Vol 52 (24) ◽  
pp. 3801-3810
Author(s):  
Klaus Banert ◽  
Manuel Heck ◽  
Andreas Ihle ◽  
Erik Michael ◽  
Richard Weber
Keyword(s):  
Ring Opening ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Model Compound ◽  
Ring Cleavage ◽  
Open Chain ◽  
Tert Butyl ◽  
Steric Crowding ◽  
Acid Catalyzed ◽  
Subsequent Acid

AbstractEpoxidation of olefinic heterocyclic amines and subsequent acid-catalyzed hydrolysis or alternatively the direct dihydroxylation with the help of osmium tetroxide led to diols, which underwent ring cleavage in the presence of lead tetraacetate to give 3-isopropyl-2,2,4,4-tetramethyl-3-azahexanedial and 3-tert-butyl-2,2,4,4-tetramethyl-3-azapentanedial. Whereas the former dialdehyde is a highly unstable model compound because of a rapid intramolecular aldol reaction, the latter product proves to be isolable at room temperature. Furthermore, this compound is the first open-chain tri-tert-alkylamine establishing in a new record of steric crowding in tertiary amines. Strong tendencies to a Hofmann-like elimination reaction or to ring-closing reactions were observed when the aldehyde units of 3-tert-butyl-2,2,4,4-tetramethyl-3-azapentanedial were transformed into other functionalities, since both types of reactions led to a significantly decrease of the steric stress.

Ring-opening reactions of .alpha.-oxy epoxides with tert-butyl dilithioacetoacetate

1978 ◽  
Vol 43 (4) ◽  
pp. 788-789 ◽  
Author(s):  
Gerard R. Kieczykowski ◽  
Michael R. Roberts ◽  
Richard H. Schlessinger
Keyword(s):  
Ring Opening ◽  
Tert Butyl ◽  
Ring Opening Reactions
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