Polyurethane-41 is an inorganic chemical compound, a segmented block copolymer derived from urethane and synthesised from isocyanates.
The name describes the structure of the molecule:
- "Polyurethane" is a term that describes a class of polymers widely used in various applications due to their versatility and desirable properties such as durability, flexibility and abrasion resistance and temperature variations.
- "-41" is a reference to the specific type or grade of polyurethane, which can be characterized by such factors as the types of isocyanates and polyols used, their relative amounts, and the presence of any additives. . This is a designation used to differentiate different molecular structures or variants of the polymer. In cosmetic chemistry, these numbers can help formulators identify specific characteristics or behaviors of a given ingredient, particularly when a chemical family has multiple derivatives or forms.
Significant substances used in the production method:
1,4-Butanediol, polytetramethylene glycol and isophorone diisocyanate (IPDI) monomers.
Description of raw materials used in production with their functions.
- 1,4-Butanediol. A type of alcohol that provides flexibility and moisture resistance to polyurethane formulations.
- Polytetramethylene glycol. Commonly used in the production of elastomers for its resilience, toughness, and flexibility.
- Isophorone diisocyanate (IPDI). IPDI is a widely used aliphatic diisocyanate monomer known for its light stability and weather resistance.
Step-by-step summary of industrial chemical synthesis process.
- Start with the reaction of 1,4-Butanediol and Polytetramethylene glycol to form a polyol prepolymer.
- This polyol prepolymer is then reacted with IPDI to form a polyurethane prepolymer.
- This polyurethane prepolymer is then chain extended or crosslinked to form the final polyurethane polymer.
What it is used for and where
Cosmetics
Film-forming agent. It produces a continuous ultra-thin film with an optimal balance of cohesion, adhesion and stickiness on the skin or hair to counteract or limit damage from external phenomena such as chemicals, UV rays and pollution.
Hair conditioning agent. A large number of ingredients with specific purposes can co-exist in a hair shampoo: cleansers, conditioners, thickeners, mattifying agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersing agents that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioners includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners.
Skin protectant. It creates a protective barrier on the skin to defend it from harmful substances, irritants, allergens, pathogens that can cause various inflammatory conditions. These products can also improve the natural skin barrier and in most cases more than one is needed to achieve an effective result.
It appears as a white powder or colorless liquid.
Safety
Urethane (also called ethyl carbamate) is a by-product of fermentation and is considered a genotoxic agent.
Polyurethanes are rather complex, inert and biostable materials that are also used in biomedical applications. They are typically synthesised by the reaction of a glycol or polyol with polyisocyanate or diisocyanate. It is known that exposure to isocyanates can cause asthma, contact allergies, conjunctival and skin irritation. However, a study by the Cosmetic Ingredient Review Expert Panel in 2017 found that the rates of harmful residues are not significant for human health.
