Effect of the remaining lanthanide catalysts on the hydrolytic and enzymatic degradation of poly‐(ϵ‐caprolactone)

Abstract

Poly‐(ϵ‐caprolactone) is a biodegradable polymer, which can be used for both medical and environmental applications.Due to its multiple applications the synthesis of such a polymer has been attracting an increasing attention in the past few decades.In our work, the polymers were synthesised by bulk polymerisation, using different lanthanide halides as initiators. The lanthanide derivatives are known as very active catalysts in the ring‐opening polymerisation of cyclic esters. Moreover, they are not toxic in comparison of catalysts, which are usually used for this synthesis.In this paper, the influence of the lanthanides on both the hydrolytic and enzymatic degradation of the PCL obtained by ring‐opening polymerization of ϵ‐caprolactone with different lanthanide‐based catalysts such as: lanthane chloride (LaCl3), ytterbium chloride (YbCl3) and samarium chloride (SmCl3) was assessed.Samarium seems to slightly accelerate the hydrolytic degradation of the polymer and to slow down or inhibit its enzymatic degradation, mainly when the molecular weight of the polymer is high. The behaviour of PCL containing another lanthanide like lanthane is dependent on the nature of the metallic ion. Complete degradation, by the Lipase PS from Pseudomonas cepacia, is achieved only with Ytterbium.

Ring‐opening polymerization of 1,4‐dioxan‐2‐one initiated by lanthanum isopropoxide in bulk

“…20,21 Whereas, the unremitting seeking to more activity of new initiator systems for ROP has stimulated the investigation of complexes featuring other metals, especially rare earth elements. [34][35][36][37][38][39][40][41][42][43][44] These initiators contained Ln-O, Ln-N, Ln-H, and Ln-S, 45 which were found to initiate the ROP of cyclic esters efficiently and some of them show living character. In addition, some trivalent rare earth compounds show very low toxicity.…”

Modular approach to synthesis of property tunable biodegradable polyesters derived from poly(ϵ-caprolactone)

“…Therefore strategies involving variations in catalyst chemistry and initiating species seldom impact the important properties of the polymer such as thermal behaviour and hydrophilicity, both of which have a large impact on polymer degradation in vivo. Although, in the case of lanthanide catalysts, residual catalysts can impact PCL degradation, 4 this is an unintentional outcome. The perceived lack of tunability of the physico-chemical properties has therefore severely limited the applications of PCL in particular in drug delivery systems.…”

Biobased Contents of Biodegradable Poly(ε‐caprolactone) Composites Polymerized and Directly Molded Using Aluminium Triflate from Caprolactone with Cellulose and Inorganic Filler

“…In contrast, poly(e-caprolactone) (PCL) is a fully biodegradable thermoplastic polymer that is obtained via chemical synthesis using fossil resources. [6] In general, PCL can be prepared from e-caprolactone (CL) in a ring-opening polymerization in an inert atmosphere and in the presence of a tin catalyst. [7] Large amounts of PCL are used in urethane composites as a soft matrix component.…”

“…Many PLA products can be found in the commercial market. In contrast, poly( ε ‐caprolactone) (PCL) is a fully biodegradable thermoplastic polymer that is obtained via chemical synthesis using fossil resources 6. In general, PCL can be prepared from ε ‐caprolactone (CL) in a ring‐opening polymerization in an inert atmosphere and in the presence of a tin catalyst 7.…”