Lipase-Catalyzed Ring-Opening Polymerization of Molecularly Pure Cyclic Oligomers for Use in Synthesis and Chemical Recycling of Aliphatic Polyesters

2008 ◽  
Vol 8 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Asato Kondo ◽  
Satoko Sugihara ◽  
Maiko Kuwahara ◽  
Kazunobu Toshima ◽  
Shuichi Matsumura
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Chemical Recycling ◽  
Aliphatic Polyesters ◽  
Cyclic Oligomers

Ring-Opening Polymerization of L-lactide Initiated by Samarium(III) Acetate

2019 ◽  
Vol 3 (2) ◽  
pp. 112-119
Author(s):  
Jesús Miguel Contreras Ramírez ◽  
Dimas Medina ◽  
Francisco López-Carrasquero ◽  
Ricardo Rafael Contreras
Keyword(s):  
1H Nmr ◽  
Ring Opening ◽  
Alkali Metals ◽  
Molar Mass ◽  
Ring Opening Polymerization ◽  
Solvent Free ◽  
Size Exclusion ◽  
Polymerization Process ◽  
Molar Ratio ◽  
Aliphatic Polyesters

Background: The synthesis of the aliphatic polyesters obtained by the ring opening polymerization has been achieved using as initiators a large amount of organometallic compounds derivative from: Alkali metals, alkaline earth metals, transition metals and lanthanide metals. Of all these compounds, the lanthanide derivatives have acquired great importance in the synthesis of aliphatic polyesters, since these show a greater catalytic activity and also can provide polymer with characteristics that will be very useful in the design of biomaterials. Objective: It was proposed the synthesis of poly(L-lactida) (PL-LA) through a ring opening polymerization process of L-lactide initiated with samarium(III) acetate (Sm(OAc)3) under solvent-free melt conditions. The influence of different parameters of reaction, such as temperature, time, molar ratio monomer to initiator, on typical variables of polymers, e.g., conversion, dispersity, and molar mass, were analyzed. Methods: All polymerizations were carried out under solvent-free melt conditions in ampoules-like flasks, equipped with a magnetic stirrer. The obtained polyesters were characterized by size exclusion chromatography (SEC) and 1H-NMR. Results: The Sm(OAc)3 induces the polymerization of L-LA at high conversion, and produce polyesters with number-average molecular weights of 1.00 x 103 to 30.00 x 103 Dalton. The 1H-NMR analysis indicates a typical polymerization mechanism of coordination-insertion, with a breakdown of the acyl-oxygen bond of the L-LA. Conclusion: Sm(OAc)3 was an effective initiator for the ring-opening polymerization of L-LA. SEC chromatography showed that, at high temperatures and prolonged reaction times, the molar mass of the polyester decreases, which is associated with the transesterification collateral reactions that occur during the polymerization process.

scholarly journals Tunable and Recyclable Polyesters from CO2 and Butadiene

2021 ◽  
Author(s):  
Rachel Rapagnani ◽  
Rachel Dunscomb ◽  
Alexandra Fresh ◽  
Ian Tonks
Keyword(s):  
Carbon Dioxide ◽  
Ring Opening ◽  
High Energy ◽  
Ring Opening Polymerization ◽  
Chemical Recycling ◽  
Alternate Route ◽  
Ceiling Temperature ◽  
Chemical Feedstock

Carbon dioxide is inexpensive and abundant, and its prevalence as waste makes it attractive as a sustainable chemical feedstock. Although there are examples of copolymerizations of CO2 with high-energy monomers, the direct copolymerization of CO2 with olefins has not been reported. Herein, an alternate route to tunable, recyclable polyesters derived from CO2 and butadiene via an intermediary lactone, 3-ethyl-6-vinyltetrahydro-2H-pyran-2-one, is described. Catalytic ring-opening polymerization of the lactone by 1,5,7-triazabicyclo[4.4.0]dec-5-ene yields polyesters with molar masses up to 13.6 kg/mol and pendent vinyl sidechains that can undergo post-polymerization functionalization. The polymer has a low ceiling temperature of 138 ºC, allowing for facile chemical recycling. These results mark the first example of a well-defined polyester derived solely from CO2 and olefins, expanding access to new feedstocks that were once considered unfeasible.

Synthesis and Ring-Opening Polymerization of Poly(alkylene 2,6-naphthalenedicarboxylate) Cyclic Oligomers

1996 ◽  
Vol 29 (26) ◽  
pp. 8304-8307 ◽  
Author(s):  
Patricia Hubbard ◽  
William J. Brittain ◽  
William J. Simonsick ◽  
Charles W. Ross
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Cyclic Oligomers
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