Anionic Polymerization of β-Butyrolactone Initiated with Sodium Phenoxides. The Effect of the Initiator Basicity/Nucleophilicity on the ROP Mechanism

Polymers

Magdalena Klim¹  Piotr Kurcok¹  Tomasz Konieczny¹  Magdalena Zięba¹  Adrian Domiński¹ 

[1] Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 34, M. Curie-Sklodowskiej St., 41-819 Zabrze, Poland;

关键词: β-butyrolactone;    anionic ring-opening polymerization;    phenoxides;    polymerization mechanism;    β-lactones;    polyhydroxybutyrate;   

DOI  :  10.3390/polym11071221

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown