The physical and even the chemical properties of a polymer in a final manufactured product can be closely related to the polymer structure.

Types of polymer structure:

  • Linear
  • Random branched
  • Comb structure
  • Starburst polymers or dendrimers
  • Copolymers
  • Cross-linked

Multi-detector SEC, such as the TDA, can be used to determine a number of the factors that determine structure:

  • Branching ratio
  • Branching frequency
  • Molecular density / Intrinsic Viscosity
  • Copolymer composition
  • Backbone modification

Structure is determined using a combination of an intrinsic viscosity detector that is sensitive to density, and a light scattering detector that provides molecular weight. These parameters are used to construct a Mark – Houwink plot from which a range of structural information can be deduced.

Application example:
Acrylonitrile-butadiene copolymers, commonly called nitrile rubbers (NBR), are used widely for adhesive compounding, and gloves used for examination and cleaning.

The composition of the copolymers, the polymer cross-linking and branching as well as the molecular weight of NBR affect the macroscopic properties of NBR such as flexibility and puncture resistance.