PEG-240, primarily utilized within the “shape-memory” copolymer PEG-240/HDI Copolymer Bis-Decyltetradeceth-20 Ether, serves as a high-performance rheology modifier. This synthetic polymer creates elegant, self-leveling textures that provide a smooth, non-sticky finish and enhanced emulsion stability.
- INCI Name:
- PEG-240/HDI Copolymer Bis-Decyltetradeceth-20 Ether (often referred to simply as PEG-240 in polymer discussions)
- Chemical/Scientific Name:
- Polyethylene glycol-240/hexamethylene diisocyanate copolymer bis-decyltetradeceth-20 ether
- Common Aliases:
- Memory-shape polymer, GT-700, GT-730
| Category: | Thickeners |
| Source Origin: | Synthetic |
| Comedogenic Rating: | 0 |
| Primary Industries: | Cosmetics, Personal Care |
| Solubility: | Water-soluble |
At a Glance: Properties & Effects
| Texture Enhancement | |
| Formula Stability | |
| Hydration/Moisture | |
| Irritation Risk |
Primary Benefits:
- Creates unique “shape-memory” textures where the product surface levels itself after use.
- Improves the spreadability and sensory profile of heavy creams.
- Functions as a non-ionic associative thickener that works across a wide pH range.
- Provides a refreshing, “water-break” sensation upon application.
Potential Risks:
- Synthetic origin may not align with “all-natural” marketing standards.
- Minimal risk of irritation, though highly sensitive individuals should patch test.
Biological Action & Cosmetic Profile
As an associative thickener, PEG-240 functions by forming a transient three-dimensional network within the aqueous phase of a formula. The hydrophobic ends of the polymer chain associate with other hydrophobic components, such as oil droplets or other polymer chains, while the hydrophilic PEG backbone interacts with Aqua. This dual-nature interaction builds viscosity and creates the characteristic “bouncing” or “jello-like” consistency found in high-end gel creams.
The molecular weight of PEG-240 ensures that the ingredient remains on the surface of the stratum corneum rather than penetrating the skin barrier. Consequently, the polymer contributes to a humectant-like film that reduces TEWL (Transepidermal Water Loss) indirectly by supporting the structural integrity of the cosmetic film. Unlike traditional carbomers, this copolymer maintains its thickening efficiency in the presence of salts and electrolytes, making it compatible with various botanical extracts and active ingredients.
Rheological studies indicate that this polymer exhibits significant shear-thinning behavior. Upon application, the mechanical force of rubbing breaks the temporary associations, allowing the product to flow easily and feel lightweight. Once the force is removed, the network rapidly reforms, which explains why the product surface in a jar appears untouched or “reset” after several minutes.
Routine Integration
Synergies:
- Works exceptionally well with Glycerin and Butylene Glycol to enhance the “cushion” feel of a moisturizer.
- Pairs with Dimethicone to create a velvet-smooth primer or night mask.
- Stabilizes formulas containing Caprylic Capric Triglyceride by providing a robust network that prevents phase separation.
Conflicts:
- No known chemical conflicts; however, excessive use of high-molecular-weight silicones may occasionally lead to pilling if the polymer network is disrupted.
Clinical Consensus & Safety
The Cosmetic Ingredient Review (CIR) Expert Panel and SCCS have evaluated polyethylene glycols (PEGs) and their related copolymers, concluding they are safe for use in cosmetics when formulated to be non-irritating. PEG-240 is a large molecule with a high degree of polymerization, which significantly limits its potential for dermal absorption or systemic toxicity. Standard impurity monitoring ensures that residuals like ethylene oxide or 1,4-dioxane are kept well below safety thresholds, often confirmed through vacuum stripping during manufacturing. Dermatological testing typically classifies this ingredient as non-sensitizing and non-comedogenic.
Is PEG-240 the same as microplastics?
No, PEG-240/HDI Copolymer is a water-soluble polymer and does not fall under the typical definition of solid microplastic beads. It dissolves in the formula to modify texture rather than remaining as a persistent solid particle.
Why does my cream look like jelly and then flatten out?
This is the “shape-memory” effect. The polymer creates a structural bridge in the jar that recovers its shape after being disturbed, ensuring the product looks fresh for every use.
Is this ingredient safe for acne-prone skin?
Yes. Because it is a large synthetic polymer that does not penetrate the pores or provide a food source for acne-causing bacteria, it has a comedogenic rating of 0.