Organic SEC

Analyte

In organic solvent soluble polymers

• Sample mass: ~ 100 mg
• Molar mass range: 10³ - 10⁷ g/mol

Equipment

• Eluent: organic solvents e.g. tetrahydrofurane (THF), chloroform, toluene, dimethylformamide, dimethylsulfoxide (DMSO), if necessary with salt additive e.g. DMSO + 0.9 M NaNO₃
• Detection: refractometer, UV-detector, viscometer, multi angle laser light scattering (MALLS) detector
• Special feature: column tempering

Evaluation methods and targets

• Conventional calibration
  with polystyrene and polymethylmethacrylate
  => average molar masses (M_w , M_n); polydispersity index D
• Universal calibration
  by means of viscometry
  => intrinsic viscosity [ η ]; M_w; M_n; D
• Absolute molar mass determination
  by means of static light scattering
  => molar mass weight average M_W; average radius of gyration <R_gz> ; M_n; D

Additionally, in special cases an analysis of copolymer and structure composition can be performed.

Application examples

• Reaction control of the synthesis of polyquinolines (PDF)
• Enzymatic modification of starch (PDF)

Contact

Dr. Sylvia Radosta
Research devision
Biopolymers
phone +49 (0) 331/ 568-1608
fax +49 (0) 331/ 568-3116
email Sylvia.Radosta@iap.fraunhofer.de

Dr. Hendrik Wetzel
Research devision
Biopolymers
phone +49 (0) 331/ 568-1604
fax +49 (0) 331/ 568-3110
email Hendrik.Wetzel@iap.fraunhofer.de

Comparative and additional methods

• Membrane osmometry (M_n)
• Analytical ultracentrifugation (M_Z; D)
• Static light scattering (M_W; R_Z; A₂)
• Differentialrefraktometrie (dn/dc)
• dynamische Lichtstreuung (d_H)
• Dampfdruckosmometrie (M_n)