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Introduction
Bis-aminopropyl diglycol dimaleate is a revolutionary compound known for its ability to restore and protect the disulfide bonds in human hair.
This molecule has become widely recognized due to its role as the active ingredient in Olaplex hair care products.
It is especially useful during and after chemical treatments such as bleaching, coloring, and heat styling, where it repairs the internal hair structure.
The chemistry of this compound offers significant benefits for cosmetic science and continues to be a research focus in biomimetic repair materials.
Chemical Name: Bis-aminopropyl diglycol dimaleate
CAS Number: 1265967-20-9
Synonyms:
Bis-Aminopropyl Diglycol Dimaleate,Bis-aminopropyl DGD Maleate,Diglycol Bis(aminopropyl) Dimaleate,OLAPLEX active ingredient
Chemical Structure and Properties
Molecular Formula: C12H20N2O8
Molecular Weight: 320.3 g/mol
Chemical Structure:
Central diglycol backbone
Two terminal aminopropyl chains
Two esterified maleate groups
Physical Properties:
Appearance: Clear to pale yellow viscous liquid
Odor: Faint chemical odor
Solubility: Highly soluble in water and alcohols
pH (1% aqueous solution): 4.5–5.5
Melting Point: Not applicable (liquid at room temperature)
Boiling Point: >100°C (decomposes)
Flash Point: >93°C (non-flammable)
Synthesis and Manufacturing
The synthesis of bis-aminopropyl diglycol dimaleate involves several key steps:
Preparation of Diglycol Backbone: The base molecule, diglycol, is prepared through the reaction of ethylene glycol with ethylene oxide.
Esterification Reaction: Maleic anhydride is reacted with the hydroxyl groups of diglycol in the presence of a catalyst (e.g., sulfuric acid or p-toluenesulfonic acid) to form diglycol dimaleate.
Aminopropyl Substitution: The maleate ester is then reacted with aminopropylamine to introduce the terminal amino groups via nucleophilic substitution.
Purification: The crude product is purified by distillation and/or chromatography to remove unreacted materials and byproducts.
Care must be taken to control the pH and temperature during synthesis to prevent degradation or overreaction.
The reaction yields are typically high, ranging between 85–95% under optimized conditions.
Spectroscopic Characterization
To confirm the identity and purity of bis-aminopropyl diglycol dimaleate, several spectroscopic methods are employed:
1H NMR: Displays characteristic peaks corresponding to:
Aminopropyl CH2 groups (~1.5–3.0 ppm)
Vinyl protons of maleate (~6.0–6.5 ppm)
OCH2CH2 groups from diglycol (~3.2–4.0 ppm)
13C NMR: Carbonyl carbons (~170–175 ppm), aliphatic chain carbons (~30–60 ppm)
FTIR:
Broad peak at ~3300 cm⁻¹ (N–H stretching)
Sharp C=O peaks at ~1720 cm⁻¹ (ester carbonyl)
C=C stretching at ~1640 cm⁻¹
Mass Spectrometry (MS): Confirms molecular weight with peak at m/z = 320.3
UV-Vis Spectroscopy: Shows low absorbance, indicating non-aromatic structure.
Reactivity and Stability
Bis-aminopropyl diglycol dimaleate is generally stable under standard storage conditions.
However, the following points must be considered:
Stability:
Hydrolytically stable at neutral to slightly acidic pH
Ester bonds may hydrolyze under strong acidic or basic conditions
Reactivity:
Amines may react with strong oxidants
Maleate groups can undergo Michael addition with nucleophiles
Storage Recommendations:
Store at 15–25°C in airtight containers
Protect from direct sunlight and moisture
Use within 24 months of manufacturing
Mechanism of Action in Hair Care
Hair fibers are composed of keratin, which relies on disulfide (S–S) bonds for strength and elasticity. Chemical treatments like bleaching and dyeing can break these bonds, leading to damage.
Mechanism:
Bis-aminopropyl diglycol dimaleate penetrates the hair cortex.
The maleate moieties interact with sulfhydryl (-SH) groups.
The compound bridges broken disulfide bonds, reforming the cross-links.
Results in restored strength and improved resistance to future damage.
This targeted repair action is unique among hair care ingredients, giving it a clinical and long-term impact on hair quality.
Applications in Hair Products
The use of bis-aminopropyl diglycol dimaleate has transformed modern hair care products. It is used in:
Professional Treatments: Included in salon-exclusive bonding treatments that are applied before, during, or after chemical processes.
Consumer Hair Care Products: Found in shampoos, conditioners, masks, and serums for regular home use.
Chemical Protection Additive: Mixed directly into bleach, dye, or perm formulations to reduce damage.
Post-Treatment Bond Maintenance: Applied as part of a multi-step regimen to maintain hair health over time.
These applications provide not just cosmetic benefits but also functional repair of hair’s internal structure.
SAFETY INFORMATION ABOUT BIS-AMINOPROPYL DIGLYCOL DIMALEATE
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product
