Polymer Synthesis and Characterization
The Jülich Centre for Neutron Science (JCNS-1) and the Institute for Neutron Scattering and Biological Matter (IBI-8) features its own polymer synthesis and characterization division. The synthesis facility is particularly equipped and designed for anionic polymerization. The polymerizations are performed under high vacuum using either Schlenk techniques, or completely sealed glass reactors. For the polymerization of liquid gas monomers, e.g. ethylene oxide, the equipment is complemented by a stainless steel Büchi reactor. For manipulating and storing air and moisture sensitive materials an Argon glove box (MBraun) is available.
On the basis of a long lasting experience model polymers of different kind can be prepared ranging from linear and branched homo- and block copolymers to rings, regular stars and polymer grafted nanoparticles of well defined molecular weight, molecular weight distribution and functionality.
For hydrogenation (deuteration) two high pressure reactors from Berghof are employed. They are mainly used for the production of polyolefines from anionically polymerized polydienes.
For neutron scattering experiments we routinely prepare deuterium labelled polymers from deuterated monomers which are either commercially available or produced in house by classical organic synthesis.
Complementary to the polymer synthesis facility we operate a characterisation lab mainly equipped with instruments for the determination of molecular weight characteristics: Further analytical methods for chemical characterisation are available in the Central Divison of Analytical Chemistry of Forschungszentrum Juelich.
Basic equipment of the polymer synthesis and characterisation division
- Glove box, MBraun, for handling of sensitive materials under inert gas
- Three vacuum lines equipped with turbo pump, oil pump and vacuum gauge are in use for anionic polymerization
- Stainless steel Büchi reactor for polymerizing liquid gas monomers
- Two stainless steel high pressure autoclaves from Berghof for hydrogenation reactions
- Size exclusion chromatography: For the determination of relative and absolute molecular weights, and molecular weight distributions
1. Agilent Technologies (PL GPC 220) with integrated refractive index detection. Eluant: THF/DMA at 40°C for polar polymers e.g. PEO, PPO, PBO or Toluene for PDMS. High temperature option: up to 220°C for polymers soluble only at high temperatures, e.g. PE, PP.
2. Agilent Technologies (PL-GPC.50) combined with Viscotek Model TDA300 triple detection array for online refractice index, viscosity and light scattering detection. Eluant: THF; Temperature: 30°C for non-polar polymers, e.g. PS, PB, PI.
- Osmometer: For the determination of number average molecular weight, Mn
1. Gonotec Osmomat090, Membrane osmometer, Nominal range: 10 g/mol<Mn<500Kg/mol
2. Knauer: Vapour Pressure Osmometer, Nominal Range: <10Kg/mol
- Multi Angle Light Scattering instrument and Differential Refractometer: For the determination of the weight average molecular weight, Mw, and the refractive index increment, dn/dc.
1. Wyatt DAWN Heleos II, 18 angle light scattering instrument for absolute molecular weight and size determination
2. Wyatt Optilab Rex refractive index detector for dn/dc and absolute refractive index detection