Degradable polyisoprene by radical ring-opening polymerization and application to polymer prodrug nanoparticles.

Radical ring-opening polymerization (rROP) has received renewed attention to incorporate cleavable linkages into the backbones of vinyl polymers, especially from cyclic ketene acetals (CKAs). Among the monomers that hardly copolymerize with CKAs are (1,3)-dienes such as isoprene (I). This is unfortunate since synthetic polyisoprene (PI) and its derivatives are the materials of choice for many applications, in particular as elastomers in the automotive, sport, footwear, and medical industries, but also in nanomedicine.

RAFT-Mediated Emulsion Polymerization-Induced Self-Assembly for the Synthesis of Core-Degradable Waterborne Particles.

Poly(N-acryloylmorpholine) (PNAM)-decorated waterborne nanoparticles comprising a core of either degradable polystyrene (PS) or poly(n-butyl acrylate) (PBA) were synthesized by polymerization-induced self-assembly (PISA) in water. A PNAM bearing a trithiocarbonate chain end (PNAM-TTC) was extended via reversible addition-fragmentation chain transfer (RAFT)-mediated emulsion copolymerization of either styrene (S) or n-butyl acrylate (BA) with dibenzo[c,e]oxepane-5-thione (DOT). Well-defined amphiphilic block copolymers were obtained.

One-Step Synthesis of Degradable Vinylic Polymer-Based Latexes via Aqueous Radical Emulsion Polymerization.

Aqueous emulsion copolymerizations of dibenzo[c,e]oxepane-5-thione (DOT) were performed with n-butyl acrylate (BA), styrene (S) and a combination of both. In all cases, stable latexes were obtained in less than two hours under conventional conditions; that is in the presence of sodium dodecyl sulfate (SDS) used as surfactant and potassium persulfate (KPS) as initiator. A limited solubility of DOT in BA was observed compared to S, yielding to a more homogeneous integration of DOT units in the PS latex.