Nanoscale Blends between Immiscible Polymers via Simultaneous Non-Interfering Polymerisation
An important topic in polymer science seeks to improve the performances of polymer blends using nanoscale phase segregation. Here, blends between polystyrene and polycaprolactone are realised by a chemical route. The non-interfering character of the radical polymerisation of styrene and the lanthanide halide initiated ring-opening polymerisation of caprolactone is assessed. The molecular weights range from 2 000 to 3 500 for polycaprolactone and up to 140 000 for polystyrene, with reasonable polydispersity indexes. From calorimetry measurements, it is shown that polystyrene and low molecular weight polycaprolactone are immiscible. The morphology of the blends between the two immiscible poly…
The Mechanism of Diene Polymerisation by Organolanthanide Catalysts Deduced from Microwave Experiments
Isoprene polymerisation performed under microwave irradiation with [Nd(BH 4 ) 3 (THF) 3 ]/Mg(Bu) 2 and [Nd-(BH 4 ) 3 (THE) 3 ]/Al(Et) 3 showed an enhancement in reactivity, with selectivity being only slightly modified. An explanation of the observed effect is proposed based on our current knowledge of the catalytic mechanism and by considering the alkylated complex as an ion pair. An analogy is proposed with the pseudoanionic polymerisation of oxygenated monomers. Finally, depolymerisation is observed under microwave irradiation at high temperature.