Ring-opening polymerization of lactams. Living anionic polymerization and its applications

Hashimoto, Kazuhiko

doi:10.1016/s0079-6700(00)00018-6

Cited by 138 publications

(105 citation statements)

References 79 publications

Supporting

Mentioning

102

Contrasting

Order By: Relevance

“…Among polymerization of various cyclic amides [1], the anionic ring-opening polymerization (ROP) of e-caprolactam is one of the most studied processes [1,2]. The activated anionic ROP of e-caprolactam is usually started with a two-component catalytic system, consisting of lactam anion or their precursor as an initiator and N-acyllactam-type activator [1,2].…”

Section: Introductionmentioning

confidence: 99%

Activated anionic ring-opening polymerization of ε-caprolactam with magnesium di(ε-caprolactamate) as initiator: effect of magnesium halides

et al. 2011

View full text Add to dashboard Cite

The activated anionic ring-opening polymerization of e-caprolactam initiated by 0.35 mol% of combined initiator, i.e., equimolar mixture of magnesium di(e-caprolactamate) (CL 2 Mg) with magnesium halides (MgCl 2 , MgBr 2 , and MgI 2 ) as well as of e-caprolactam magnesium bromide (CLMgBr) in the presence of 0.35 mol% of N-acetyl-e-caprolactam as an activator has been investigated in the temperature range 140-200°C. It was found that the reaction rate increased while the apparent activation energy decreased in the following series: CL 2 Mg/ MgCl 2 \ CL 2 Mg/MgBr 2 * CLMgBr \ CL 2 Mg/MgI 2 . In addition, the poly(ecaprolactam)s prepared with CL 2 Mg/MgX 2 (MgX 2 = MgCl 2 , MgBr 2 , and MgI 2 ) are characterized by slightly higher thermal stability than polymers obtained with CLMgBr as initiator. These observations were explained in terms of the coordination of Lewis acids (MgX 2 , where X = Cl, Br, and I) with imide carbonyl of N-acyllactam end groups leading to the increase of their reactivity and stability.

show abstract

Section: Introductionmentioning

confidence: 99%

Activated anionic ring-opening polymerization of ε-caprolactam with magnesium di(ε-caprolactamate) as initiator: effect of magnesium halides

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Because glycine anhydride is a weak base, a much stronger base than glycine anhydride is needed to open and polymerize glycine anhydride. Dibutyltin(IV) diacetate, a nonionic catalyst like Sn(OCt) 2 , and t-BuOK, a stronger base than Sn(OCt) 2 , commonly used in anionic ring-opening polymerization of cyclic amides or lactams for preparation of polyamides [29][30][31] or polypeptides 12 , were investigated. Previous studies reported that an initiator such as t-BuOK rapidly initiates lactide polymerization, but side reactions, such as deprotonation, causing racemization of the lactide monomer, are also induced 32 .…”

Section: Resultsmentioning

confidence: 99%

Untitled

Noomhorm¹,

Tokiwa²

2008

ScienceAsia

View full text Add to dashboard Cite

Poly(ester-amide)s were prepared by ring-opening copolymerization of L-lactide with glycine anhydride to form poly(lactide-co-glycine) and with alanine anhydride to form poly(lactide-co-alanine). At 195 o C there were about 5.7 mol% inclusion of glycine using potassium tert-butoxide as catalyst in poly(lactideco-glycine) and 5.0 mol% inclusion of alanine using tin(II) bis-2-ethylhexanoate as catalyst in poly(lactideco-alanine). Enzymatic degradation studies showed that both copolymers could be degraded by proteinase K and glycine and alanine were included in their respective copolymers.

show abstract

“…The anionic polymerization of lactams [188,189] is usually via a so-called activated anionic mechanism with a two-component catalyst system from a strong base and an N-acyllactam. It is interesting in the sense that the active center of the growing chain is an N-acyllactam end group to which a lactamate anion, formed from the monomer, is added (Scheme 7.7).…”

Section: Monomermentioning

confidence: 99%

“…mer, here the transamidation, together with the propagation-depropagation of the cyclic monomer and macrocycles, will broaden the molecular weight distribution [189]. This polymerization has attracted much attention because it is very fast compared to the hydrolytic polymerization of e-caprolactam, which takes several hours, whereas the anionic polymerization is complete within minutes, even below the melting point of the polymer.…”

Section: Monomermentioning

confidence: 99%