Sinocure Chemical Group Co.,Ltd.

Other Catalysts And Additives

Sinaint® Phenolphthalein

SINAINT® Phenolphthalein is a weak organic acid. It is white or slightly yellow fine crystals at room temperature. It is odorless and tasteless. It is hardly soluble in water but easily soluble in alcohol (ethanol) and ether. Dissolved in alcohol solution to make acid-base indicator, it is colorless in acid solution, red in lye or alkali metal carbonate solution, but if it is in concentrated alkali solution, it will generate colorless trimetal The salt, the red faded. In view of this characteristic, it is often used as an indicator of acid-base titration in laboratories. The color range of PH value is 8.2~10.0, from colorless to red. When the phenolphthalein reagent is dripped into water or a neutral, acidic aqueous solution, white turbidity will appear. This is because alcohol is easily soluble in water, and phenolphthalein, which is hardly soluble in water, precipitates out in the reagent.


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SKU SCGNK019 Category

SINAINT® Phenolphthalein

Synonym Name:2-[Bis(4-hydroxyphenyl)methyl]benzoic acid; 3,3-Bis(4-hydroxyphenyl)-1(3H)-isobenzofuranone; 3,3-Bis(4-hydroxyphenyl)phthalide

Cas No. :77-09-8

Melting point: 261-263 °C (lit.)

Boiling point: 417.49°C

Flash point: 24 °C

Molecular structure:



Item Specifications
Characteristics A white or almost white powder, practically insoluble in water, soluble in alcohol.
Melting Point It melts at about 260℃
Identification A:Positive B:Positive
Appearance of solution The solution is clear and not more intensely coloured than reference solution Y7
Related substances Less than 0.5%
Heavy metals Not more than0.001%
Acidity or alkalinity Complies
Chlorides Not more than 0.01%
Sulphates Not more than 0.02%
Loss on drying Not more than 0.5%
Sulphated ash Not more than 0.1%
Assay 98.0%-101.0%(C2OHi4O4)
Microorganism TPC<1000cfu/g
Y and M <100cfu/g
E-coli – absent
Staphylococcus Aureus-Absent
Pseudomonas Aeruginosa-Absent
Albicans Saccharomyces-Absent


1. Pharmaceutical raw materials for the pharmaceutical industry: suitable for habitual stubborn constipation, with various dosage forms such as tablets and suppositories.
2. Used in organic synthesis: mainly used in the synthesis of plastics, especially the synthesis of phthalazinone polyaryl ether ketone polyaryl ether ketone polymers, which have excellent heat resistance, water resistance and chemical resistance Corrosion, heat aging resistance and good processing and formability, fibers, coatings and composite materials made from them have soon been widely used in electronic appliances, mechanical equipment, transportation, aerospace, atomic energy engineering and military fields.
3. Used as acid-base indicator, indicator for non-aqueous titration, reagent for chromatography.

Packaging and Shipping:

Fiber Drum,25kg


Stored in a cool dry place out of direct sunlight.


Other name


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