Determination for end carbonyl in polyester - Titrimetric analysis
1 Scope
This standard specifies two titrimetric analysis methods for determination for end carboxyl in polyester, i.e. visual method (method A) and photometric method (method B). In case of dispute, visual method is adopted.
This standard is applicable to the determination for end carboxyl in polyester as the intermediate product and the final product in the production process with terephthalic acid and ethylene glycol as raw materials. It may be referenced by other polyesters.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
GB/T 601-2002 Chemical reagent - Preparations of standard volumetric solutions
GB/T 8170 Rules for rounding off of numerical values
GB/T 14666-1993 Terms for analytical chemistry
3 Terms and definitions
For the purposes of this standard, the terms and definitions given in GB/T 14666-2003 apply.
4 Test methods
4.1 Method A - Visual method
4.1.1 Principle
Reflux and dissolve the specimen in the mixed solvent of phenol - trichloromethane. After cooling, titrate the solution with potassium hydroxide - ethanol standard volumetric solution using bromophenol blue as indicator. According to the consumed volume of standard volumetric solution, calculate the content of end carbonyl.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Test methods
