Synthesis of Polylactide with Thiol End Groups

2003 ◽  
Vol 68 (6) ◽  
pp. 1131-1140 ◽  
Author(s):  
Štěpán Popelka ◽  
František Rypáček

Four synthetic routes to poly(L-lactide) with thiol end groups based on ring-opening polymerization of L-lactide (LA) catalysed with tin(II) 2-ethylhexanoate (Sn(Oct)2) are reported. The following alcohols were used as co-initiators of polymerization: 2-sulfanylethan-1-ol, 2-[(2,4-dinitrophenyl)sulfanyl]ethan-1-ol, 2-(tritylsulfanyl)ethan-1-ol and allyl alcohol. End groups introduced into polymers by co-initiators were transformed to thiol groups by a subsequent modification reaction. The efficiencies of the used synthetic methods were evaluated and discussed. The best results were obtained with co-initiator 2-(tritylsulfanyl)ethan-1-ol.

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1221 ◽  
Author(s):  
Adrian Domiński ◽  
Tomasz Konieczny ◽  
Magdalena Zięba ◽  
Magdalena Klim ◽  
Piotr Kurcok

It was shown that selected sodium phenoxide derivatives with different basicity and nucleophilicity, such as sodium p-nitrophenoxide, p-chlorophenoxide, 1-napthoxide, phenoxide and p-methoxyphenoxide, are effective initiators in anionic ring-opening polymerization (AROP) of β-butyrolactone in mild conditions. It was found that phenoxides as initiators in anionic ring-opening polymerization of β-butyrolactone behave as strong nucleophiles, or weak nucleophiles, as well as Brønsted bases. The resulting polyesters possessing hydroxy, phenoxy and crotonate initial groups are formed respectively by the attack of phenoxide anion at (i) C2 followed by an elimination reaction with hydroxide formation, (ii) C4 and (iii) abstraction of acidic proton at C3. The obtained poly(3-hydroxybutyrate) possesses carboxylate growing species. The ratio of the observed initial groups strongly depends on the basicity and nucleophilicity of the sodium phenoxide derivative used as initiator. The proposed mechanism of this polymerization describes the reactions leading to formation of observed end groups. Moreover, the possibility of formation of a crotonate group during the propagation step of this polymerization is also discussed.


2009 ◽  
Vol 131 (4) ◽  
pp. 1589-1597 ◽  
Author(s):  
Jihua Zhang ◽  
Denis A. Kissounko ◽  
Sarah E. Lee ◽  
Samuel H. Gellman ◽  
Shannon S. Stahl

2011 ◽  
Vol 332-334 ◽  
pp. 1490-1493
Author(s):  
Chun Wang Yi ◽  
Nan Fan Li ◽  
Chao Sheng Wang ◽  
Zhi Han Peng ◽  
Shi Yan Chen

In this study,a new thermoplastic elastomer based on polyamid 6, and polytetrahydrofuran was prepared by continuous hydrolytic ring-opening polymerization process. The effective of adipic acid content on the number-average molecular and the content of amino end groups was investigated. The morphology deduce of TPMP, mechanical performances were also investigated.


2019 ◽  
Vol 10 (3) ◽  
pp. 296-305 ◽  
Author(s):  
Yu Dai ◽  
Xiaojin Zhang

The synthetic methods and applications of cationic polycarbonates via ring-opening polymerization are highlighted.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1554
Author(s):  
Tian Xing ◽  
Mark R. J. Elsegood ◽  
Sophie H. Dale ◽  
Carl Redshaw

The reaction of [Mo(η-C5Me5)Cl4] with the ortho-, meta-, or para-iodo-functionalized anilines 2-IC6H4NH2, 3-IC6H4NH2, 4-IC6H4NH2 yields imido or amine products of the type [Mo(η-C5Me5)Cl2(IC6H4N)] (2-I, 1, 3-I, 3, 4-I, 5) or [Mo(η-C5Me5)Cl4(IC6H4NH2)] (3-I, 2, 4-I, 4), respectively, depending on the reaction stoichiometry/conditions; we were unable to isolate an amine complex of the 2-I derivative. The reaction of [Mo(η-C5Me5)Cl4] with one equivalent of 2-I,4-FC6H3NH2 in the presence of Et3N afforded [Mo(η-C5Me5)Cl2(2-I,4-FC6H3N)]·MeCN (6·MeCN), which, upon exposure to air, afforded the Mo(VI) imido complex [Mo(η-C5Me5)Cl3(2-I,4-FC6H3N)] (7). For comparative studies, the structure of the aniline (C6H5NH2)-derived complex [Mo(η-C5Me5)Cl2(2-C6H3N)] (8) has also been prepared. The molecular structures of 1–8 have been determined and reveal packing in the form of zig-zag chains or ladders. The complexes catalyze, in the presence of benzyl alcohol under N2, the ring-opening polymerization (ROP) of ε-caprolactone affording relatively low molecular weight products. The MALDI-ToF spectra indicate that a number of polymer series bearing a variety of end groups are formed. Conducting the ROPs as melts or under air results in the isolation of higher molecular weight products, again bearing a variety of end groups. Kinetic studies reveal the aniline-derived imido complex 8 performs best, whilst a meta-iodo substituent and a Mo(V) centre are also found to be beneficial. The structures of the side products 2-IC6H4NH3Cl and 3-IC6H4NH3Cl are also reported.


Synlett ◽  
2019 ◽  
Vol 30 (18) ◽  
pp. 2051-2057 ◽  
Author(s):  
Andreas F. M. Kilbinger

Over the last two decades many synthetic methods have been reported to selectively introduce a number of different functional groups at the chain end of a living ring-opening metathesis polymer. In this personal account, I would like to focus on a few such methods developed in my research group over the last several years and how these led to the discovery of catalytic living ring-opening metathesis polymerization, a ring-opening metathesis polymerization method controlled by the polymer end groups. This account consists of the following sections:1 Introduction2 Functionalization of the Propagating Chain End3 Functionalization of the Initiating Chain End4 Polymerization Control by Functional End Groups5 Conclusions


2020 ◽  
Vol 21 (24) ◽  
pp. 9581
Author(s):  
Si-Ting Lin ◽  
Chung-Chi Wang ◽  
Chi-Jung Chang ◽  
Yasuyuki Nakamura ◽  
Kun-Yi Andrew Lin ◽  
...  

This review presents the latest developments in (bio)degradable approaches and functional aliphatic polyesters and polycarbonates prepared by typical ring-opening polymerization (ROP) of lactones and trimethylene carbonates. It also considers several recent innovative synthetic methods including radical ring-opening polymerization (RROP), atom transfer radical polyaddition (ATRPA), and simultaneous chain- and step-growth radical polymerization (SCSRP) that produce aliphatic polyesters. With regard to (bio)degradable approaches, we have summarized several representative cleavable linkages that make it possible to obtain cleavable polymers. In the section on functional aliphatic polyesters, we explore the syntheses of specific functional lactones, which can be performed by ring-opening copolymerization of typical lactone/lactide monomers. Last but not the least, in the recent innovative methods section, three interesting synthetic methodologies, RROP, ATRPA, and SCSRP are discussed in detail with regard to their reaction mechanisms and polymer functionalities.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4402
Author(s):  
Quentin Barnes ◽  
Claire Longuet ◽  
François Ganachaud

Ring-opening ionic polymerization of cyclosiloxanes in dispersed media has long been discovered, and is nowadays both fundamentally studied and practically used. In this short communication, we show some preliminary results on the cationic ring-opening polymerization of hexamethylcyclotrisiloxane (D3), a crystalline strained cycle, in water. Depending on the catalyst or/and surfactants used, polymers of various molar masses are prepared in a straightforward way. Emphasis is given here on experiments conducted with tris(pentafluorophenyl)borane (BCF), where high-molar polymers were generated at room temperature. In surfactant-free conditions, µm-sized droplets are stabilized by silanol end-groups of thus generated amphiphilic polymers, the latter of which precipitate in the course of reaction through chain extension. Introducing various surfactants in the recipe allows generating smaller emulsions in size with close polymerization ability, but better final colloidal stability, at the expense of low small cycles’ content. A tentative mechanism is finally proposed.


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