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.

Ring-opening polymerization of ethylene carbonate using ionic liquids as catalysts

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiancheng Zhou ◽  
Ling Cheng ◽  
Dongfang Wu
Keyword(s):  
Ionic Liquids ◽  
Ring Opening ◽  
Ethylene Carbonate ◽  
Molar Fraction ◽  
Reaction System ◽  
Monomer Conversion ◽  
Catalytic Performance ◽  
Ring Opening Polymerization ◽  
Polymerization Catalysts ◽  
Chain Cleavage

AbstractThe ring-opening polymerization of ethylene carbonate was examined using ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and 1-butyl-3-methylimidazolium chlorozincate ([bmim]Cl-(ZnCl2)x), as polymerization catalysts. It was shown that the polymerization was accompanied with decarboxylation and chain cleavage reaction. As the reaction time increased, the monomer conversion increased and the content of ethylene carbonate units in the resultant polymer decreased, while the polymer molecular weight increased at first, reached a maximum and then decreased. It was also found that not only the polymerizing activity of the [bmim]Cl-(ZnCl2)x but also its performance for suppressing the decarboxylation and chain cleavage increased with the molar fraction of ZnCl2. It was deduced that the catalytic performance of ionic liquids mainly depended on their inorganic anions and that the larger the amount of these anions in the reaction system, the better the catalytic performance. The polymerizing activity of ionic liquids was much higher than conventional catalysts often used for the polymerization of ethylene carbonate.

scholarly journals Improved thermally stable oligoetherols from 6-aminouracil, ethylene carbonate and boric acid

2019 ◽  
Vol 17 (1) ◽  
pp. 1080-1086
Author(s):  
Elżbieta Chmiel-Szukiewicz
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Boric Acid ◽  
Ethylene Carbonate ◽  
Pyrimidine Ring ◽  
Polyurethane Foams ◽  
High Thermal Stability ◽  
H Nmr ◽  
Maldi Tof ◽  
Instrumental Methods

AbstractSyntheses of oligoetherols with a 1,3-pyrimidine ring and boron atoms using 6-aminouracil, ethylene carbonate and boric acid has been proposed. The structure of the obtained products were determined by instrumental methods (IR, 1H-NMR and MALDI-ToF spectra). The physicochemical and thermal properties of oligoetherols were examined. The products were characterized by high thermal stability. Based on the tests performed, it was found that oligoetherols obtained from 6-aminouracil, boric acid and ethylene carbonate are suitable for the manufacturing of polyurethane foams with improved thermal stability and reduced flammability.

Anionic Ring-Opening Polymerization Simulations for Hyperbranched Polyglycerols with Defined Molecular Weights

2013 ◽  
Vol 46 (21) ◽  
pp. 8458-8466 ◽  
Author(s):  
Florian Paulus ◽  
Maximilian E. R. Weiss ◽  
Dirk Steinhilber ◽  
Anatoly N. Nikitin ◽  
Christof Schütte ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Molecular Weights ◽  
Anionic Ring

scholarly journals Dinitrosyl rhenium complexes for ring-opening metathesis polymerization (ROMP)

2006 ◽  
Vol 78 (10) ◽  
pp. 1877-1887 ◽  
Author(s):  
Christian Manfred Frech ◽  
Olivier Blacque ◽  
Heinz Berke
Keyword(s):  
Phosphine Oxide ◽  
Ring Opening ◽  
Density Functional ◽  
Ring Opening Metathesis Polymerization ◽  
Olefinic Bond ◽  
Metathesis Polymerization ◽  
Molecular Weights ◽  
Cyclic Olefins ◽  
Phosphine Complexes ◽  
Unique Reaction

The treatment of benzene solutions of the cations [Re(NO)2(PR3)2][BArF4] (R = Cy and R = iPr; [BArF4] = tetrakis{3,5-bis(trifluoromethyl)phenyl}borate) with phenyldiazomethane afforded the moderately stable cationic rhenium(I) benzylidene dinitrosyl bis(trialkyl) phosphine complexes as [BArF4]- salts in good yields. The cationic rhenium dinitrosyl bisphosphine complexes catalyze the ring-opening metathesis polymerization (ROMP) of highly strained nonfunctionalized cyclic olefins to give polymers with relatively high polydispersity indices, high molecular weights, and Z configurations of the double bonds in the polymer chain backbones of over 80 %. The benzylidene derivatives are almost inactive in ROMP catalysis with norbornene and in olefin metathesis. NMR experiments gave first hints for the initial formation of carbene complexes when [Re(NO)2(PR3)2][BArF4] was treated with norbornene. The carbene formation is initiated by an unique reaction sequence where the cleavage of the strained olefinic bond starts with phosphine migration forming a cyclic ylid carbene complex. The [2+2] addition of a norbornene molecule to the Re=C bond leads to the rhenacyclobutane complex, which is expected to be converted into an iminate complex by attack of the ylid function onto one of the NNO atoms followed by Wittig-type phosphine oxide elimination. The formation of phosphine oxide was confirmed by NMR spectroscopy. This species is thought to drive the ROMP metathesis with alternating rhenacyclobutane formations and cycloreversions. The proposed mechanism is supported by density functional theory (DFT) calculations.

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 Polyols Prepared from Ring-Opening Epoxidized Soybean Oil by a Castor Oil-Based Fatty Diol

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Zhang ◽  
Ji Jun Tang ◽  
Jiao Xia Zhang
Keyword(s):  
Soybean Oil ◽  
Castor Oil ◽  
Ring Opening ◽  
Epoxidized Soybean Oil ◽  
Epoxy Ring ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Epoxy Ring Opening ◽  
Ft Ir

Several biorenewable vegetable oil-based polyols with different molecular weights and various hydroxyl functionalities were successfully prepared by ring-opening epoxidized soybean oil with a castor oil-based fatty diol. It was found that several factors, including reaction time, reaction temperature, and molar ratios between epoxidized soybean oil and castor oil diol, affect structures and rheology behaviors of the final polyols. Proton NMR, FT-IR, GPC, and rheometry results revealed that the hydroxyl functionalities, molecular weight, and viscosity of the polyols could be tailored by controlling the above-mentioned factors. Besides, the role of solvents in the epoxy ring-opening process was investigated as well.

Simultaneous drug release at different rates from biodegradable polyurethane foams

2009 ◽  
Vol 5 (7) ◽  
pp. 2398-2408 ◽  
Author(s):  
Wesley N. Sivak ◽  
Jianying Zhang ◽  
Stephané Petoud ◽  
Eric J. Beckman
Keyword(s):  
Drug Release ◽  
Polyurethane Foams ◽  
Biodegradable Polyurethane

scholarly journals Synthesis and crossover reaction of TEMPO containing block copolymer via ROMP

2010 ◽  
Vol 6 ◽  
Author(s):  
Olubummo Adekunle ◽  
Susanne Tanner ◽  
Wolfgang H Binder
Keyword(s):  
Dicarboxylic Acid ◽  
Ring Opening ◽  
Laser Desorption ◽  
Ring Opening Polymerization ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
Block Copolymerization ◽  
Molecular Weights ◽  
Ionization Mass Spectroscopy ◽  
Rate Of Polymerization

We report on the block copolymerization of two structurally different norbornene monomers (±)-endo,exo-bicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylic acid dimethylester (7), and (±)-endo,exo-bicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylic acid bis(1-oxyl-2,2,6,6-tetramethyl-piperidin-4-yl) ester (9) using ruthenium based Grubbs’ type initiators [(PCy3)2Cl2Ru(benzylidene)] G1 (PCy3 = tricyclohexylphosphine), [(H2IMes)(PCy3)Cl2Ru(benzylidene)] G2 (H2IMes = 1,3-bis(mesityl)-2-imidazolidinylidene), [(H2IMes)(py)2Cl2Ru(benzylidene)] G3 (py = pyridine or 3-bromopyridine) and Umicore type initiators [(PCy3)2Cl2Ru(3-phenylinden-1-ylidene)] U1 (PCy3 = tricyclohexylphosphine), [(H2IMes)(PCy3)Cl2Ru(3-phenylinden-1-ylidene)] U2 (H2IMes = 1,3-bis(mesityl)-2-imidazolidinylidene), [(H2IMes)(py)Cl2Ru(3-phenylinden-1-ylidene)] U3 (py = pyridine or 3-bromopyridine) via ring opening polymerization (ROMP). The crossover reaction and the polymerization kinetics were investigated using matrix assisted laser desorption ionization mass spectroscopy (MALDI-TOF) and nuclear magnetic resonance (NMR), respectively. MALDI showed that there was a complete crossover reaction after the addition of 25 equivalents of the second monomer. NMR investigation showed that U3 gave a faster rate of polymerization in comparison to U1. The synthesis of block copolymers with molecular weights up to M n = 31 000 g/mol with low polydispersities (M w/M n = 1.2) is reported.

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