Molecular and colloid chemical characterization

Analyte

• Polymers soluble in organic solvents
• Sample size: ~ 100 mg
• Molar mass range: 10² - 10⁷ g/mol

Equipment

• Eluent: organic solvents such as tetrahydrofuran (THF), chloroform (TCM), dichloromethane (DCM), hexafluoroisopropanol (HFIP), toluene, dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), if necessary with salt addition, e. g. NaNO₃, LiBr, CF₃COONa
• Detectors: RI refractometer; UV detector; viscometer; multi-angle light scattering (MALLS), evaporative light scattering detector ELSD, RI / viscosity combination detector
• Special features: column temperature control, fraction collector for semi-preparative use

Target

• Conventional calibration with PS, PMMA, PEG, PEO, PLA and Pullulan
• Molar mass averages (M_W, M_n), polydispersity index D
• Universal calibration by viscometry
• Intrinsic viscosity [ η ], M_W, M_n, D
• Absolute molar mass determination by means of static light scattering
• Mass average M_W, average gyration radius <R_gz>, M_n, D
• Furthermore, copolymer or structural analysis can be performed in certain cases

Application

• Reaction monitoring of the synthesis of polyquinolines (see PDF)
• Enzymatic modification of starch (see PDF)
• Determination of the molar mass of polymers and copolymers based on lactic acid
• Determination of the conversion rate in polymer synthesis
• Determination of the molar mass of polyethylene terephthalates and polyacrylonitriles

Methods of comparison and supplementation

• Membran osmometry (M_n)
  
• Analytical ultracentrifugation (M_Z; D)
  
• Static light scattering (M_W; R_Z; A₂)
• Dynamic light scattering (d_H)
  
• Differential refractometry (dn/dc)
• Vapor pressure osmometry (M_n)