HSP Conservation Planner & 3D Visualizer

Solvent Database

Click any solvent to inspect its RED score and location in 3D HSP space.

Solvent Name	δD	δP	δH	B-72 RED	Acrylic RED	Selectivity

Acetone

Dimethyl Ketone | CAS 67-64-1

Danger Zone

HSP Coordinates

15.5, 10.4, 7.0

Teas (fd, fp, fh)

47, 32, 21 %

Paraloid B-72 RED

0.72 (Soluble)

Acrylic Substrate RED

0.54 (Soluble)

Conservation Notes:

Extremely high danger to modern acrylic polymers. Readily swells and dissolves acrylic emulsion paints within seconds. Unusable as a selective cleaning agent.

Binary Solvent Blender

Combine a polar/hydrogen-bonding solvent and a non-polar solvent to discover highly selective binary mixes that dissolve B-72 while leaving the acrylic safely unswollen.

Solvent A (Active Agent)

HSP: 15.8, 8.8, 19.4 Teas: 36, 20, 44%

Solvent B (Diluent/Carrier)

HSP: 16.8, 0.0, 0.2 Teas: 99, 0, 1%

Solvent A: 20% Solvent B: 80%

100% A 50:50 Mix 100% B

Classic Conservation Mixtures:

Selectivity Profile & Sweet Spot Optimization

0% (100% Sol B) 50% 100% (100% Sol A)

The Chemistry of Selective Removal

In paintings conservation, removing protective polymer layers like Paraloid B-72 (ethyl methacrylate / methyl acrylate copolymer) from sensitive substrates like cured acrylic resin paint represents a delicate thermomechanical and thermodynamic puzzle.

Because both materials are synthetic acrylic formulations, they share highly overlapping solubilities. This visual planner utilizes Hansen Solubility Parameters to exploit subtle geometric differences in their 3D solubility spheres:

Paraloid B-72: $\delta_D = 17.6$, $\delta_P = 6.4$, $\delta_H = 7.0$ | Radius $R_0 = 8.0$
Acrylic Paint Substrate: $\delta_D = 17.8$, $\delta_P = 10.2$, $\delta_H = 7.4$ | Radius $R_0 = 8.5$

By calculating the Relative Energy Difference (RED), we categorize interactions:

RED < 1.0 Soluble / Complete swelling

RED 1.0 – 1.1 Marginal swelling / Mild safety hazard

RED > 1.1 Insoluble / Safe boundary

The Conservator's Sweet Spot:

An ideal selective cleaning system possesses a $RED_{B72} < 1.0$ and a $RED_{Acrylic} > 1.1$. This ensures that B-72 dissolves and is picked up onto swabs, while the underlying paint film remains structurally sound without risk of pigment pick-up, solvent retention, or swelling.

Academic Citations & Literature Sources

Stefan Zumbühl, et al. (2014) "Parametrization of the solvent action on modern artist's paint systems." Journal of the American Institute for Conservation (JAIC).
Established core solubility limits, swelling mechanics, and the dynamic resistance of acrylic binders during chemical cleaning treatments.
Armand Vinçotte, Emmie Beauvoit, Nicolas Boyard & Elodie Guilminot (2019) "Effect of solvent on PARALOID® B72 and B44 acrylic resins used as adhesives in conservation." Heritage Science.
Detailed empirical analysis mapping actual solvent retention, dry glass transition temperature ($Tg$) deviations, and the solubility behavior of conservation film replicates.
Alan Phenix (2002) "The solubility of artists' acrylic emulsion paint films." Studies in Conservation.
Investigated swelling and solvent interaction profiles of commercially available acrylic emulsions including Golden® Paint systems using Hansen and Teas conceptual models.
Charles M. Hansen (2007) "Hansen Solubility Parameters: A User's Handbook." Second Edition, CRC Press.
The authoritative textbook mapping empirical standard three-dimensional solubility coefficients and the math governing polymers, resins, and complex chemical mixtures.