Synthesis of submicron particles of a stereoregular polyolefin by catalysis in aqueous dispersion : Supporting information

General considerations. All manipulations of air-sensitive compounds were performed using standard Schlenk techniques under argon atmosphere. NMR spectra were recorded with either a Bruker ARX 300, Bruker Avance DRX 600 or Varian INOVA-400 spectrometer. H and C NMR chemical shifts were referenced to H and C NMR signals of the deuterated solvents, respectively. High temperature NMR measurements were performed in 1,1,2,2-tetrachloroethane-d2 at 130°C and at 100°C. IR spectra were recorded on a FT-IR Bruker Vector 22 spectrometer using KBr pellets. Dynamic light scattering (DLS) on dispersions was performed on a Malvern Nano-ZS ZEN 3600 particle sizer (173° back scattering). Differential scanning calorimetry (DSC) was performed on either a Perkin-Elmer DSC 7, a Pyris 1 DSC or a Netzsch DSC 204 F1 at a heating rate of 10 K/min. The polymers were investigated in the temperature range 25-230°C. DSC data reported are second heats. Transmission electron microscopy (TEM) was carried out on a LEO 912 Omega apparatus using an acceleration voltage of 120 kV. Samples were prepared by applying a drop of the dispersion to a carbon coated grid. Molecular weight determination was done with a PL GPC-220 device using a Mixed B column with a refractive index detector, in trichlorobenzene at 160°C vs. polyethylene standards. Materials. Ruthenium(III) tris-2,4-pentanedionate (Merck) and triphenylphosphine (Aldrich) were used without further purification. Hydrogen (99.999 % purity) was purchased from Messer-Griesheim and used as received. Toluene was distilled from sodium under argon. 1,2polybutadiene latices were synthesized according to reference [1] and were degassed using an argon stream before hydrogenation. Hydrogenation procedure. The hydrogenation was carried out in a mechanically stirred 285 mL high-pressure reactor equipped with a heating/cooling block controlled by a thermocouple dipping into the reaction mixture. The 1,2-polybutadiene dispersion (40 mL; 4-6% solids content), previously degassed, was introduced in the reactor under an argon atmosphere. The catalyst was prepared by mixing ruthenium(III) tris-2,4-pentanedionate and triphenylphosphine, in a 1:4 molar ratio, in 2 mL of toluene. After stirring for about 5 minutes the red solution obtained was transferred to the reactor. The reactor was flushed and pressurized with hydrogen, while rapidly heating to 125°C under stirring (1000 rpm). After the specified reaction time, the reaction was stopped by cooling and releasing the pressure. The polymer dispersion was taken out of the reactor with a syringe and further analyzed. For NMR, IR, DSC and GPC analysis the dispersion was added to methanol under stirring and the precipitated polymer was filtrated , washed with methanol and dried at 50°C under vacuum overnight.