Einführung

Einführung

What is a Polymer Disperison?

Systems consisting of polymer particles with a size in the nanometer range dispersed in a nonsolvent for the polymer are called polymer dispersions. The particles must be stabilized against coagulation in a proper way.

Synthesis of Polymer Disperisons
The preparation of polymer dispersions is possible either by heterophase polymerization in the dispersion medium (primary dispersions) or by emulsification of polymer solutions in the dispersion medium (secondary dispersions).

Schematic drawing of the course of a heterophase polymerization with monomer feed. The reaction starts in a homogeneous system (left) and ends with the formation of a polymer dispersion (right) via the steps nucleation and growth.
Schematic drawing of the course of a heterophase polymerization with monomer feed. The reaction starts in a homogeneous system (left) and ends with the formation of a polymer dispersion (right) via the steps nucleation and growth.

Properties and Meaning of Polymer Disperisons
Polymer dispersions possess several astonishing properties as low viscosity at high concentrations, an adjustable viscosity in dependence on shear rate, or the formation of crystals. But the most important property is their stability against coagulation as from a thermodynamic point of view polymer dispersions should be unstable. Polymer dispersions are an essential part of our daily life. For example, they find application as binders for environmentally friendly paints and coatings but also as aids and appliances in cancer therapy. The most important polymer dispersions are waterborne (primary dispersions) or waterbased (secondary dispersions). The science of polymer dispersions is a unique interplay between colloid chemistry, polymer chemistry and reaction engineering. Polymer dispersions have a great industrial importance (some 25.000.000 tons/year are produced world wide) and in this field trained students have good chances in industry.

 
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