Summary

In Lesson 3, we got a more in depth look at step polymerization. Using the Carothers equation, we now understand the relationship between extent of reaction, reactant ratio, and the degree of polymerization. Out of these relationships, we learned that in order to achieve high degrees of polymerization, we need to go to high extents of reaction and have a reactant ratio as close to 1 as possible. We also used statistical theory to derive expressions for the probability of finding an x-mer, the weight fraction of x-mers, and the number fraction of x-mers. From these, we can learn about the distribution of the polymer molar mass for different extents of reaction.

Reminder - Complete all of the Lesson 3 tasks!

You have reached the end of Lesson 3! Review the checklist on the Lesson 3 Overview / Checklist page to make sure you have completed all of the activities listed there before you begin Lesson 4.