Perodox® F - tert-Butyl peroxyacetate

tert-Butyl peroxyacetate (TBPA) is an organic peroxide compound primarily used as a free-radical initiator for polymerizing vinyl monomers and as a crosslinking agent for thermoset resins like unsaturated polyesters.

The CAS Registry Number for tert-Butyl peroxyacetate is 107-71-1. This unique identifier is used globally in chemical databases and regulatory documents.

The molecular formula is C6H12O3.

The IUPAC name is tert-butyl ethaneperoxoate.

It is typically a clear, colorless to pale yellow liquid with a characteristic, sharp, ether-like or ester-like odor.

The molecular weight is 132.16 grams per mole.

Its density is approximately 0.94 - 0.96 g/cm³ at 20°C, which is slightly less than that of water.

tert-Butyl peroxyacetate decomposes explosively before boiling. It should never be heated to its boiling point. The SADT (Self-Accelerating Decomposition Temperature) is a much more critical parameter, typically around 40°C.

The flash point is approximately 35°C (Tag Closed Cup), classifying it as a flammable liquid.

The typical active oxygen content is a minimum of 9.4%, which indicates its peroxide concentration and initiator potential.

It is practically insoluble in water. However, it is miscible with most common organic solvents such as aliphatic and aromatic hydrocarbons, esters, and ketones.

The half-life (time for 50% decomposition) in an inert solvent at 100°C is approximately 10 hours.

At 120°C, the half-life is significantly shorter, typically around 1-2 hours, making it suitable for high-temperature curing processes.

Its primary use is as a free-radical initiator for the polymerization of vinyl monomers (like styrene, vinyl acetate) and as a crosslinking agent (curing agent) for unsaturated polyester resins (UPR) in fiberglass reinforced plastics.

It is mixed with unsaturated polyester resin (often containing styrene). When heated, it decomposes to generate free radicals that initiate the crosslinking reaction between the polyester chains and the styrene monomer, transforming the liquid resin into a solid, thermoset plastic.

No, tert-Butyl peroxyacetate requires heat to decompose efficiently (typically >80°C). For room temperature curing, other peroxides like methyl ethyl ketone peroxide (MEKP) are used in combination with accelerators (cobalt naphthenate).

It is not a common initiator for PVC (polyvinyl chloride) suspension or emulsion polymerization, which typically uses peroxides like di(2-ethylhexyl) peroxydicarbonate. Its use is more common in higher-temperature solution or bulk polymerizations and thermoset crosslinking.

It is used to initiate the polymerization of styrene (to make polystyrene, ABS, etc.), methyl methacrylate (PMMA), vinyl acetate (PVA), and various acrylate monomers for adhesives, coatings, and acrylic sheets.

In peroxide-cure silicone rubber (HTV), TBPA decomposes at vulcanization temperatures to generate radicals that abstract hydrogen atoms from the silicone polymer's methyl groups, creating polymer radicals that combine to form stable carbon-carbon crosslinks between chains.

Yes, it is a hazardous material. It is a strong oxidizer, flammable liquid, and can cause severe skin/eye burns. It is thermally unstable and can undergo self-accelerating exothermic decomposition if heated, contaminated, or stored improperly.

The Self-Accelerating Decomposition Temperature (SADT) is critical, typically around 40°C. It must be stored at temperatures significantly below this, preferably under 25°C/77°F, and often requires refrigeration.

Storage at controlled room temperature (below 25°C) may be acceptable for short periods per the manufacturer's specific SDS, but refrigeration is generally recommended for safety and to maintain product stability during extended storage.

It is incompatible with strong acids, strong bases, reducing agents, accelerators, metallic salts, amines, sulfur compounds, and other organic peroxides. Incompatible materials can catalyze violent decomposition.

Use water spray, fog, foam, or dry chemical powder to extinguish surrounding fire. Do NOT use a direct jet of water on the peroxide itself, as it may spread the material. Evacuate the area and let the fire burn if safe to do so, as explosive decomposition risk is high.

Mandatory PPE includes chemical safety goggles, face shield, flame-retardant/anti-static clothing, and chemical-resistant gloves (e.g., nitrile rubber). Respiratory protection may be needed if ventilation is insufficient.

Immediately remove contaminated clothing. Wash skin thoroughly with plenty of water and soap for at least 15 minutes. Seek immediate medical attention. Contaminated clothing should be cleaned before reuse or discarded.

Evacuate the area. Eliminate all ignition sources. Wear full protective gear. Contain the spill with inert, non-combustible absorbent material (e.g., sand, vermiculite). Collect spillage in a suitable, labeled container for disposal by a specialist. Do not use combustible materials like sawdust. Ventilate the area.

It decomposes thermally via homolytic cleavage of the relatively weak peroxide (-O-O-) bond, generating two radical species: a tert-butoxy radical (•OC(CH₃)₃) and an acetyloxy radical (CH₃COO•). These radicals then initiate polymerization or abstract hydrogen atoms.

Primary thermal decomposition products include acetone, methane, ethane, carbon dioxide, and tert-butanol. The exact products depend on temperature and the chemical environment.

Decomposition is accelerated by heat, contamination (especially with acids, bases, metals, or reducing agents), friction, impact, and confinement.

It is not typically classified as a primary explosive, but like most organic peroxides, it can be sensitive to mechanical shock, friction, or impact when contaminated, confined, or in large quantities. Always handle with care to avoid dropping or severe impact.

Process temperatures are chosen based on the desired reaction speed. A temperature where the half-life is 1-10 minutes is often used for fast curing (e.g., 130-140°C), while a half-life of 1 hour (e.g., 120°C) is used for slower, controlled processes like pultrusion or compression molding.

tert-Butyl peroxyacetate, stabilized, typically falls under UN 3105, ORGANIC PEROXIDE TYPE C, LIQUID.

GHS classifications usually include: Oxidizing Liquids (Category 2), Flammable Liquids (Category 2), Acute Toxicity (Oral/Skin/Inhalation, Category 4), Skin Corrosion/Irritation (Category 1B), and Specific Target Organ Toxicity (Single Exposure, Category 3). Check the SDS for the precise classification of the specific product.

Major global producers and suppliers include companies like Shandong Do Sender Chemicals Co.,Ltd.,United Initiators, Nouryon, Pergan, and Arkema.

Yes, it is almost always shipped under temperature-controlled conditions (often at or below 25°C) to ensure safety during transport, in accordance with regulations for organic peroxides.

When stored under recommended conditions (refrigerated), the shelf life is typically 6 to 12 months. Always check the manufacturer's label and SDS for the specific product's expiry date and storage recommendations.

tert-Butyl peroxybenzoate has a higher decomposition temperature (half-life of 1 hour at ~130°C vs. ~125°C for the acetate). The benzoate is often used for higher-temperature curing applications, while the acetate is more active at slightly lower temperatures.

MEKP is a low-temperature initiator used with cobalt accelerators for room-temperature cure of polyester resins (like in boat building). TBPA is a thermal initiator requiring heat (>80°C) and is used for hot press molding, pultrusion, or high-temperature resin casting.

Dicumyl peroxide is a solid with an even higher decomposition temperature (1-hour half-life ~140°C), used for crosslinking polyethylene and EPDM. TBPA, a liquid, is chosen for lower-temperature cure cycles (e.g., 110-130°C) or when a liquid initiator is needed for easier blending with liquid resins.

Yes, tert-Butyl peroxyacetate is more reactive (decomposes at a lower temperature) than di-tert-butyl peroxide because the peroxyacetate group is less stable than the peroxy-tert-butyl group, making the O-O bond easier to break.

Premature cure can be caused by: 1) Storage of the peroxide or resin at too high a temperature, 2) Contamination of equipment with accelerators (e.g., cobalt, amines), 3) Using an excessively high initiator concentration, 4) Exothermic heat buildup in large batches.

The amount is typically 0.5% to 2.0% by weight of the resin, depending on the resin type, desired cure speed, and part thickness. The calculation is based on the active oxygen content of the peroxide and the required radical concentration for the specific resin system.

Possible reasons: 1) Insufficient initiator amount, 2) Cure temperature too low or time too short for the peroxide's half-life, 3) Inhibition by oxygen (air inhibition at the surface), 4) Use of an expired or degraded peroxide, 5) Resin formulation issues (e.g., incorrect monomer ratio).

Yes, but fillers and pigments must be inert and free of moisture, reducing agents, or metallic compounds that could decompose the peroxide. Some pigments (e.g., carbon black, certain iron oxides) can inhibit cure and require testing.

Gel time is highly resin-dependent. For a standard orthophthalic unsaturated polyester resin with 1% TBPA at 100°C, the gel time might be in the range of 5 to 15 minutes. A DSC (Differential Scanning Calorimetry) test is needed for precise data.

Gel time is highly resin-dependent. For a standard orthophthalic unsaturated polyester resin with 1% TBPA at 100°C, the gel time might be in the range of 5 to 15 minutes. A DSC (Differential Scanning Calorimetry) test is needed for precise data.

Gel time is highly resin-dependent. For a standard orthophthalic unsaturated polyester resin with 1% TBPA at 100°C, the gel time might be in the range of 5 to 15 minutes. A DSC (Differential Scanning Calorimetry) test is needed for precise data.

A spill poses fire and explosion hazards. It is toxic to aquatic life. It can contaminate soil and water. Due to its oxidising nature, it may increase the biological oxygen demand (BOD) in water bodies and react with other substances. Immediate containment and professional remediation are required.