We report the synthesis and characterization of high-molecular weight poly(l-glutamic acid) based brush polymers. Utilizing a combination of ring-opening metathesis polymerization of norbornene based monomers and ring-opening polymerization of γ-benzyl-l-glutamate N-carboxyanhydride, high-molecular weight γ-benzyl protected poly(l-glutamic acid) brush polymers are synthesized. Controlled and co...

PLA emerged as a promising polymer because of its property as a compostable, biodegradable thermoplastic made from renewable sources. PLA can be polymerized from monomers (Lactide or Lactic acid) obtained by fermentation processes from renewable sources such as corn starch or sugarcane. For PLA synthesis, ring opening polymerization (ROP) of Lactide monomer is one of the preferred methods. In t...

Hybrid copolymers, which contain segments with distinct structures and properties, are useful materials in various applications such as novel plastics, polymeric catalysis, smart materials, self-assembly, and bionanotechnology. They can be prepared through conjugation of hybrid polymeric segments or polymerization with corresponding initiators. The latter approach is particularly attractive as ...

S Chapter 1 Study of Chiral Arylimido Molybdenum ROMP Catalysts. Molybdenum ROMP catalysts with a chiral ortho-(phenethyl)phenylimido ligand have been prepared. Mo(CHCMe2Ph)(N-2-C 6H4-CHMePh)(O-2,6-C 6H3-Ph2)2 (1la) and Mo(CHMe 2Ph)(N2-C6H4-CHMePh)[BIPHENO(Me) 2(t-Bu) 4] (11b) were isolated and shown to effect the polymerization of 2,3-dicarbomethoxynorbonadienes. Highly-trans syndiotactic poly...

A dual catalytic system combining an original cationic zinc complex and a tertiary amine is shown to promote efficiently the polymerization of lactide under mild conditions.

For the first time, the controlled ring-opening polymerization (ROP) of ε-thionocaprolactone (tnCL) is conducted. The organocatalytic ROP of tnCL occurs without carbonyl scrambling, leading to homopoly(ε-thionocaprolactone) (PtnCL). The ROP by base catalysts alone is proposed to proceed via a nucleophilic mechanism, while the addition of an H-bond donating thiourea (TU) is shown to provide exce...

A family of chiral zinc amido-oxazolinate complexes are shown to be highly active and isoselective initiators for the ring-opening polymerization (ROP) of rac-lactide, yielding isotactic stereoblock polylactides (PLA) with Pm up to 0.91. This represents the highest isoselectivity observed with zinc-based catalysts for ROP of rac-lactide.

Paclitaxel, a polyol chemotherapeutic agent, was covalently conjugated through its 2'-OH to polylactide with 100% regioselectivity via controlled polymerization of lactide mediated by paclitaxel/(BDI-II)ZnN(TMS)(2) (BDI-II = 2-((2,6-diisopropylphenyl)amino)-4-((2,6-diisopropylphenyl)imino)-2-pentene). The steric bulk of the substituents on the N-aryl groups of the BDI ligand drastically affecte...

A new graft copolymer, poly(2-hydroxyethyl methacrylate-co-styrene) -graft-poly( -caprolactone), was prepared by combination of reversible addition-fragmentation chain transfer polymerization (RAFT) with coordination-insertion ringopening polymerization (ROP). The copolymerization of styrene (St) and 2-hydroxyethyl methacrylate (HEMA) was carried out at 60 °C in the presence of 2-phenylprop-2-y...

A series of lithium complexes were prepared from 2(N-piperazinyl-N'-methyl)-2-methylene-4-R'-6-R-phenols ([ONN](RR')) and characterized through elemental analysis, (1)H and (13)C{(1)H} NMR spectroscopy, and X-ray crystallography. Treatment of the ligands with n-butyllithium afforded {Li[ONN](RR')}(3) [R = Me, R' = (t)Bu, (1); R = R' = (t)Bu (2); R = R' = (t)Am, (3), (t)Am = C(CH(3))(2)CH(2)CH(3...