Branching Calculations

When using a DAWN or miniDAWN to make molar mass measurements, it is possible to perform sophisticated branching calculations to determine the branching of a polymer sample. ASTRA can determine the degree of tri- or tetrafunctional branching, and even analyze star and comb polymers. If the molar mass and rms radius for a linear and corresponding branched polymer are measured, then ASTRA can calculate the following quantities:

  • branching ratio gM.
  • branch units per molecule.
  • long chain branching.
In addition, if the polymer is too small (rms radius < 10 nm) for size measurements using light scattering, ASTRA can use the mass method for samples with known Mark-Houwink parameters and common elution times.

branching analysis GUI
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The branching analysis view puts everything at your fingertips to make branching calculations simple. Choose between four different polymer types: tri- or tetra-functional, star, or comb branching. Enter parameters for long chain branching, or the mass method. Finally, instantly view results by selecting the plot type. Displayed at left is the interface with a comparison of conformation plots and slopes for a linear and branched sample.

The following plots demonstrate the other visual information available in the branching analysis view:

branching ratio

branch units per molecule

long chain branching

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