Lewis acidic yttrium(III) and titanium(IV) derivatives of anionic, metal-tethered carbenes apparently act as bifunctional catalysts for the polymerisation of D,L-lactide, using a combination of Lewis acid and base functionalities to initiate ring opening of the cyclic monomer; the alcohol- and amino-functionalised carbenes from which they derive provide models for the first insertion step, and ...

The reaction of Sm{N(SiMe3)2}3 with the bis(phenol)amines H2O2N(R) (H2O2N(R) = RCH2CH2N(2-HO-3,5-C6H2(t)Bu2)2; R = OMe, NMe2 or Me) gave exclusively zwitterions Sm(O2N(R))(HO2N(R)). For R = OMe or NMe2 these were efficient catalysts for the ring-opening polymerisation of epsilon-caprolactone and D,L-lactide with a tendency to form cyclic esters; in contrast, no polymerisation was observed for R...

Polylactide (PLA) is a biodegradable polyester which is able to replace petrochemical based plastics in many fields [1]. It is commonly produced by ring-opening polymerisation (ROP) of the cyclic diester lactide with metal containing initiator systems using anionic ligand systems [2]. Zinc complexes with neutral guanidine ligands have proven to be highly active initiators in the ROP of lactide ...

We report the polymerisation-induced self-assembly of poly(lauryl methacrylate)-graft-poly(benzyl methacrylate) copolymers during reversible addition-fragmentation chain transfer (RAFT) grafting from polymerisation in a backbone-selective solvent. Electron microscopy images suggest phase separation grafts to result network spherical particles, due ability branched architecture freeze entangleme...

The RTM process is mostly used in aeronautics and space industries. In this process the reinforcement is placed inside a mould and a low viscosity resin is injected and heated until it polymerises. The impregnation of the reinforcement and the polymerisation step are two keyelements to reach good piece quality. The knowledge of the front position of the thermosetting resin and polymerisation de...

Polylactides (PLA), biodegradable aliphatic polyesters, produced solely from renewable resources may substitute petrochemically based polymers in a broad range of applications in the near future, if we manage to produce them at lower cost and higher efficiency as nowadays. Possible applications include food packaging for meat and soft drinks, films for agro-industry and non-wovens in hygienic p...

The -diimine iron complexes have been proposed as the first example outside the realm of biomolecules where the spin-state of the transition metal involved dictates the catalytic behaviour [1]. Here, we study a typical complex of this family, R”[N,N]FeCl2, with [N,N] = Cy– N=CR”–CR”=N–Cy (Cy=cyclohexyl), R”=PhF (para-fluorophenyl), PhOMe (para-methoxyphenyl), PhNMe2 (para-dimethylaminophenyl). ...