The degree of polymerization, or DP, is the number of repeat units in an average polymer chain at time t in a polymerization reaction. The length is in monomer units. The degree of polymerization is a measure of molecular weight. For most industrial purposes, lengths in the thousands or tens of thousands are desired.

DP = Total MW of the Polymer/MW of Monomer

$M\_n=X\_nM\_o$

In polycondensation, in order to achieve a high degree of polymerization (and hence molecular weight), X_n, a high fractional monomer conversion, p, is required, as per Carother's equation: X_n = 1/(1-p). A monomer conversion of p = 99% would be required to achieve X_n = 100.

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