Copolymer and interpolymer grades extend Carbomer’s thickening performance into high-ionic-strength systems where a standard homopolymer would lose efficiency. Copolymer provides a solid foundation of salt and ion resistance; interpolymer builds on that with rapid wetting, speeding up hydration during manufacturing.
Product · Carbomer Salt-Resistant Families
Carbomer Copolymer & Interpolymer
Technical Specifications — Copolymer vs Interpolymer
| Parameter | Copolymer | Interpolymer |
|---|---|---|
| Ascend Model | AM-1382 | AM-U10 / AM-U20 / AM-U21 / AM-SF1 (Liquid Carbomer) |
| Viscosity (Cp, 0.5wt% neutralized gel in water) | 10,000 – 29,000 | 45,000 – 77,000 |
| Comparable viscosity profile to | Carbopol 1382 | Carbopol U10 / U20 / U21 / SF-1 |
| Polymerization solvent | Ethyl acetate / cyclohexane (benzene-free) | Ethyl acetate / cyclohexane (benzene-free) |
| Salt / ion resistance | Yes — foundational salt & ion resistance | Yes — enhanced, with rapid wetting |
| Wetting / hydration | Standard | Rapid |
| Liquid carbomer category | — | Included in the range |
| Pharmacopoeia compliance | EP / USP | EP / USP |
| CAS Number | 9007-20-9 | 9007-20-9 |
Copolymer
Ascend Model: AM-1382
Viscosity (Cp, 0.5wt% neutralized gel in water): 10,000 – 29,000
Comparable viscosity profile to: Carbopol 1382
Polymerization solvent: Ethyl acetate / cyclohexane (benzene-free)
Salt / ion resistance: Yes — foundational salt & ion resistance
Wetting / hydration: Standard
Liquid carbomer category: —
Pharmacopoeia compliance: EP / USP
CAS Number: 9007-20-9
Interpolymer
Ascend Model: AM-U10 / AM-U20 / AM-U21 / AM-SF1 (Liquid Carbomer)
Viscosity (Cp, 0.5wt% neutralized gel in water): 45,000 – 77,000
Comparable viscosity profile to: Carbopol U10 / U20 / U21 / SF-1
Polymerization solvent: Ethyl acetate / cyclohexane (benzene-free)
Salt / ion resistance: Yes — enhanced, with rapid wetting
Wetting / hydration: Rapid
Liquid carbomer category: Included in the range
Pharmacopoeia compliance: EP / USP
CAS Number: 9007-20-9
Choosing Between Copolymer and Interpolymer
Both families deliver salt and ion resistance that a standard homopolymer cannot — that is their common foundation. The copolymer provides this resistance at a moderate viscosity (10,000–29,000 Cp) and is the straightforward choice for higher-ionic-strength systems where the salt load is the only challenge. The interpolymer (45,000–77,000 Cp) builds on the same salt and ion resistance and adds rapid wetting: it hydrates noticeably faster during manufacturing, which matters when dispersion time is the bottleneck on your line. The interpolymer range also includes pre-neutralized liquid carbomer forms for processes that prefer to skip powder dispersion entirely. If you're unsure which fits your formulation, share your target system and process constraints and we can recommend a starting point for trial.
Interpolymer Model Breakdown
The interpolymer family covers several models within a shared viscosity range (45,000 – 77,000 Cp) — AM-U10, AM-U20, AM-U21, and the liquid form AM-SF1.
AM-U10
Dry powder — rapid-wetting grade for salt & ion-resistant thickening.
AM-U20
Dry powder — rapid-wetting grade, close performance profile to AM-U10.
AM-U21
Dry powder — rapid-wetting grade, high end of the viscosity range.
AM-SF1
Pre-neutralized liquid carbomer — instant hydration, for processes that skip powder dispersion.
AM-U10, AM-U20, and AM-U21 perform close to each other within the same viscosity band; the practical difference comes down to hydration rate and processing preference. AM-SF1 is the liquid exception — pre-neutralized and instantly hydrating. If the catalog doesn't give a finer basis for differentiation, treat the dry-powder models as interchangeable starting points and let your dispersion-time and form requirements guide the final selection — we can supply any of these models for trial.
Key Applications
Salt-Resistant Thickening
Maintains gel structure and viscosity in electrolyte-heavy systems where a standard homopolymer loses efficiency.
Rapid-Wetting Formulations
Interpolymer grades hydrate quickly, shortening dispersion time and supporting faster manufacturing cycles.
Cosmetics & Personal Care
Stable thickening in surfactant and electrolyte-rich cleansers, serums, and formulations with active salts.
Pharmaceutical Systems
Gels and topical systems requiring thickening stability alongside buffered, ion-containing actives.
Frequently Asked Questions
Should I choose the copolymer or the interpolymer?
Start with the salt and ion load of your system and your processing priorities. If you need a solid, cost-effective foundation of salt and ion resistance for a high-ionic-strength formulation, the copolymer (10,000–29,000 Cp) is the right starting point. If your manufacturing step is time-sensitive — you want the polymer to wet and hydrate quickly — or you need a higher final viscosity, the interpolymer (45,000–77,000 Cp) adds rapid wetting on top of salt and ion resistance. Share your target system and process, and we'll recommend the better fit.
What does 'liquid carbomer' mean in the interpolymer range?
Part of the interpolymer family is supplied as a pre-neutralized liquid carbomer dispersion rather than a dry powder. These liquid forms hydrate instantly and are aimed at processes where dry-powder dispersion and neutralization steps are impractical or time-consuming.
Why would my formulation need salt resistance?
Standard homopolymers lose thickening efficiency in the presence of dissolved salts and ions — common in surfactant-heavy personal care, electrolyte-containing gels, and certain pharmaceutical systems. Copolymer and interpolymer grades incorporate functional monomers that keep the gel structure stable at higher ionic strength.
Is this grade benzene-free?
Yes. These grades are manufactured using an ethyl acetate/cyclohexane co-solvent system or pure ethyl acetate as the polymerization solvent, with low solvent residue compliant with current regulatory requirements.
Do you provide certificates of analysis for each batch?
Yes, a batch-specific COA is provided with every shipment, along with ISO certification and MSDS/TDS on request.