Ring-Opening Dispersion Polymerization of ʟ-Lactide with Polylactide Stabilizer in Supercritical Carbon Dioxide

2017 ◽  
Vol 70 (6) ◽  
pp. 712 ◽  
Author(s):  
Jinjun Deng ◽  
Shiping Zhan ◽  
Jingchang Wang ◽  
Zhijun Liu ◽  
Zhiyi Li
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Ring Opening ◽  
Dispersion Polymerization ◽  
Triblock Copolymers ◽  
Molecular Weights ◽  
Fine Powders ◽  
Stabilizer Concentration ◽  
Scanning Electron ◽  
Supercritical Carbon

Non-fluorous triblock copolymers of poly(l-lactide)-block-hydroxypropyl-terminated poly(dimethyl siloxanes)-block-poly(l-lactide) (PLLA-HTPDMS-PLLA) with two different molecular weights in the range of 4800 to 6500 Da, were prepared by changing the ratio of HTPDMS to l-lactide (L-LA), and were used as stabilizers for the ring-opening dispersion polymerization (RODP) of L-LA to prepare poly(l-lactide) (PLLA) in supercritical carbon dioxide (ScCO2). The experimental results showed that the prepared non-fluorous triblock copolymers were very effective as new stabilizers for the RODP and fine powders of PLLA were obtained. The structure of the stabilizers and PLLA were characterized by 1H NMR and FTIR spectroscopy. The morphology of PLLA was investigated by scanning electron microscopy (SEM). The effects of the CO2-philic/lipophilic segment lengths of the stabilizers on the RODP were explored. The effects of the stabilizer concentration on the polymerization yield, molecular weight, and morphology of PLLA were investigated.

scholarly journals Low-temperature and purification-free stereocontrolled ring-opening polymerisation of lactide in supercritical carbon dioxide

2020 ◽  
Vol 22 (7) ◽  
pp. 2197-2202 ◽  
Author(s):  
Simon P. Bassett ◽  
Andrew D. Russell ◽  
Paul McKeown ◽  
Isabel Robinson ◽  
Thomas R. Forder ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Low Temperature ◽  
Supercritical Carbon Dioxide ◽  
Ring Opening ◽  
Solvent Free ◽  
Free Ring ◽  
First Time ◽  
Supercritical Carbon

A stereoselective, solvent-free ring-opening polymerisation (ROP) of lactide (LA) in supercritical carbon dioxide (scCO2) is reported for the first time.

Effect of stabilizer concentration and controller structure and composition on polymerization rate and molecular weight development in RAFT polymerization of styrene in supercritical carbon dioxide

Polymer ◽  
2009 ◽  
Vol 50 (21) ◽  
pp. 5024-5030 ◽  
Author(s):  
Gabriel Jaramillo-Soto ◽  
Pedro R. García-Morán ◽  
Francisco J. Enríquez-Medrano ◽  
Hortensia Maldonado-Textle ◽  
Martha E. Albores-Velasco ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Supercritical Carbon Dioxide ◽  
Raft Polymerization ◽  
Polymerization Rate ◽  
Stabilizer Concentration ◽  
Supercritical Carbon

scholarly journals Impregnation of poly(L-lactide-ran-δ-valerolactone) with essential bark oil using supercritical carbon dioxide

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chikara Tsutsumi ◽  
Souta Manabe ◽  
Susumu Nakayama ◽  
Yuushou Nakayama ◽  
Takeshi Shiono
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Azeotropic Distillation ◽  
Proteinase K ◽  
High Yield ◽  
Feed Ratio ◽  
One Pot ◽  
Molecular Weights ◽  
Hydrolysis Process ◽  
Supercritical Carbon

Abstract This work studied the incorporation of essential bark oil from Thujopsis dolabrata var. hondae, which is known to repel various insects, in poly(L-lactide-ran-δ-valerolactone) [poly(L-LA-ran-VL)] using supercritical carbon dioxide (scCO2). The poly(L-LA-ran-VL) was synthesized by first purifying the monomers by azeotropic distillation with benzene, followed by polymerization with Sn(oct)2 using the same equipment, representing an efficient one-pot process. The copolymerization of L-LA with VL using this technique at a feed ratio of 90/10 mol/mol gave poly(L-LA-ran-VL) (91/9) with a molecular weight of 6.48 × 104 g/mol and a high yield of 74.9%. Products with molecular weights over 5.0 × 104 g/mol were obtained at L-LA feed proportions of 70 to 90%. Impregnation trials were conducted between 40 and 120 °C at 14 MPa for 3 h. The oil content of a 73/27 specimen was found to increase significantly during processing at 100 or 120 °C. During enzymatic degradation with proteinase K, the 91/9 specimen showed the fastest degradation rate. Although the 71/29 sample was slowly hydrolyzed in a phosphate buffer at pH 7.0, the release of oil vapor from this material was slightly higher than that from the 91/9 specimen, and the vapor release rate continuously increased throughout the hydrolysis process.

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