Study of the Grafting of Bromoacetylated α-Hydroxy-ω-Methoxypoly(Ethyleneglycol) onto Anionically Activated Poly(∊-Caprolactone)

Abstract

Bromoacetylated α-hydroxy-ω methoxy-poly (ethyleneglycol) (Mn = 2000 g mol−1) was allowed to react with a poly(∊ caprolactone) (Mn = 53,700, Mw/Mn =(1.50) that was first activatedby removing some of the proton atoms borne by the carbon atoms locatedin -position of carbonyl groups using lithium N-N-diisopropylamide as basic reagent in tetrahydrofurane at 78°C under argon flow. The reaction resulted in the grafting of methoxy poly(ethylene glycol) segments to some of the poly("-caprolactone) chains. The resulting polymeric compounds were characterized by various analytical techniques including NMR, SEC, DSC, X-ray diffraction and contact angle. Various characteristics of the recovered compounds, namely degree of substitution, degree of crystallinity, glass transition and melting temperatures, hydrophilicity, were evaluated. It was concluded that grafting was effective but sometimes not all poly("-caprolactone) chains were modified, depending on experimental conditions. Moreover, 150 nm nanoparticles were obtained without any additional surfactant for a 0.74% substitution degree copolymer.

Novel Amphiphilic Degradable Poly(ε‐caprolactone)‐graft‐poly(4‐vinyl pyridine), Poly(ε‐caprolactone)‐graft‐poly(dimethylaminoethyl methacrylate) and Water‐Soluble Derivatives

“…The method was applied to the formation of PCL-based graft copolymers by a grafting 'from' or a grafting 'onto' technique. [11,16] In this article we report the synthesis of novel PCL-g-P4VP and PCL-g-PDMAEMA copolymers by the grafting 'from' strategy (Scheme 1).…”

“…In parallel, monomethoxypoly(ethylene glycol) (MeO-PEG, 2.5 mmol) was activated by bromoacetylation (bromoacetyl bromide, 0.25 mmol) following a method already described. [11] One equivalent of the activated MeO-PEG with regard to the e-CL units was dissolved in anhydrous THF (100 mL). The reaction was carried out for 1 h between À70 and À50 8C with stirring.…”

“…Activated MeO-PEG was obtained by reaction with bromoacetyl chloride as already described in a previous article. [11] PCL-g-P4VP has been re-activated by reaction with LDA to form a new macropolycarbanion, which reacts with the activated MeO-PEG. After purification by precipitation and dialysis, the terpolymer PCL-g-(P4VP;PEG) was characterized by 1 H NMR spectroscopy in CDCl 3 .…”

Functional modification of biodegradable polyesters through a chemoselective approach: application to biomaterial surfaces

“…Several methods to tether PEO side chains onto biodegradable polyesters have been published 77–81. However, the molecular weights of the obtained graft copolymers were generally low 77–80.…”

“…However, the molecular weights of the obtained graft copolymers were generally low 77–80. Chain cleavage of the polyester backbone can occur due to severe reaction conditions 81. Furthermore, such synthetic chemistries typically exclude the possibility for further modification of the free PEO end.…”