1440 Timberwolf Drive, PO Box 964, Holland, OH 43528-0964 USA | 1 (419) 867-5400 | Email Us

1440 Timberwolf Drive, PO Box 964, Holland, OH 43528-0964 USA
1 (419) 867-5400 | Email Us

Carboxyl End Group Analysis for PET

Sample Type Required Quantity Equipment Used
Resin Flake Preform Bottle 25 grams Titration Apparatus

Purpose

This procedure determines the carboxyl end group content in a PET sample.


Description

The procedure involves the titration of the carboxyl end groups with potassium hydroxide in an o-cresol/chloroform medium to a bromophenol blue endpoint. A known weight of PET sample is dissolved in o-cresol then chloroform and bromophenol blue are added to the solution. The solution is then titrated with potassium hydroxide until the color changes to blue as a result of the end group reaction. Based on the amount of KOH required for the titration, the quantity of carboxyl end groups is calculated.