The hydroxy groups present in a test portion are esterified with phthalic anhydride. The excess phthalic anhydrids is hydrolyzed and the phthalic acid formed is neutralized with standard volumetric sodium hydroxide solution. If the sample contains free acidity or alkalinity a corresponding correction is made. From the corrected hydroxyl number, the apparat relative molecular mass may be calculated by a formula given.
Life cycle
NOW
PUBLISHED ISO 6796:1981 90.20
Standard under periodical review Jul 15, 2024
Preview
Only informative sections of projects are publicly available. To view the full content, you will need to members of the committee. If you are a member, please log in to your account by clicking on the "Log in" button.
Shqip