Is polysuccinimide water-soluble?

No — it is essentially water-insoluble. For aqueous use it is hydrolysed to sodium polyaspartate.

Yes, via its polyaspartate derivative, which is why it is used as a greener alternative to some phosphonates and polyacrylates.

Why does PSI have several CAS numbers?

It is registered variably by molecular weight and synthesis route, so the exact CAS and molecular weight depend on the grade.

Polysuccinimide

CAS 26099-09-2 (C₄H₃NO₂)n

CAS number: 26099-09-2
Formula: (C₄H₃NO₂)n
Molar mass: 97.07 g/mol repeat unit · polymer MW ~1,000–10,000 (up to ~50,000)
Appearance: Beige to light-brown powder; virtually water-insoluble; slowly hydrolyses to polyaspartate.

Polysuccinimide (PSI) is the water-insoluble polyimide precursor to biodegradable polyaspartate, used as a “green” scale inhibitor and detergent dispersant. Ehlinar sources water-treatment and cosmetic grades, defined by molecular weight; the polymer carries more than one registered CAS number.

Applications

Water treatmentPrecursor to biodegradable polyaspartate; slow-release scale inhibitor for cooling/boiler water

DetergentsBuilder and anti-redeposition dispersant

Oilfield & agricultureFertilizer-efficiency aid and soil conditioner

Personal careFilm former

Chemical intermediatesChelation / sequestrant intermediate

Grades & packaging

Water-treatment and cosmetic grades are defined by molecular weight and appearance rather than a single assay figure.

25 kg fiber drums/bags
500–1000 kg bulk bags

Also known as

PSI · Anhydropolyaspartic acid · Poly[imino(1-oxo-1,2-ethanediyl)] · Polyaspartic-acid (PASP) precursor

Frequently asked questions

Is polysuccinimide water-soluble?: No — it is essentially water-insoluble. For aqueous use it is hydrolysed to sodium polyaspartate.
Is it biodegradable?: Yes, via its polyaspartate derivative, which is why it is used as a greener alternative to some phosphonates and polyacrylates.
Why does PSI have several CAS numbers?: It is registered variably by molecular weight and synthesis route, so the exact CAS and molecular weight depend on the grade.

Enquire about Polysuccinimide

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Figures and identifiers here are compiled from public references and provided for general information; they are indicative, not a specification. See all products.