| HS Code | |
| Productname | tert-Butanol |
| Synonyms | tert-Butyl alcohol; 2-Methyl-2-propanol; TBA |
| Iupacname | 2-Methylpropan-2-ol |
| Casnumber | 75-65-0 |
| Ecnumber | 200-889-7 |
| Molecularformula | C4H10O |
| Molarmass | 74.12 g/mol |
| Appearance | Colorless liquid or crystalline solid |
| Odor | Camphor-like |
| Density | 0.775 g/cm3 at 25 °C |
| Meltingpoint | 25.7 °C |
| Boilingpoint | 82.4 °C |
| Solubilityinwater | Miscible |
| Flashpoint | 11 °C closed cup |
| Autoignitiontemperature | 470 °C |
| Vaporpressure | 41 mmHg at 25 °C |
| Refractiveindex | 1.387 at 20 °C |
| Viscosity | 3.35 mPa·s at 30 °C |
| Pka | 19.2 |
| Logp | 0.35 |
As an accredited Tert-Butanol factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Tert-Butanol is available in 500 mL amber glass bottles with PTFE-lined caps, sealed and labeled as a flammable liquid. |
| Container Loading (20′ FCL) | Tert-Butanol loaded into 20' FCL container: palletized drums, secured, labeled UN1120 Class 3 flammable liquid, with DG documentation. |
| Shipping | Tert-Butanol is shipped as a flammable liquid under UN 1120, Proper Shipping Name BUTANOLS, Hazard Class 3, Packing Group II. Use UN-approved packaging, flammable-liquid labels/placards, and proper shipping papers. Follow DOT/IATA/IMDG rules; keep away from ignition sources, heat, and oxidizers. |
| Storage | Store tert-butanol in a cool, dry, well-ventilated, fire-safe area away from heat, sparks, open flames, and ignition sources. Keep containers tightly closed, labeled, upright, and grounded. Use flammable-liquid storage cabinets or dedicated areas with spill containment. Separate from strong oxidizers, acids, and other incompatible materials. Ensure adequate ventilation and comply with local fire and chemical storage regulations. |
| Shelf Life | Tert-Butanol is stable; typical shelf life is about two years when stored sealed, cool, dry, and away from ignition sources. |
Tert-butanol solidifies at 25.7 °C and has a closed-cup flash point of 11 °C; therefore any bulk transfer system in ambient service must maintain line temperatures above 30 °C. The six application scenarios below are restricted to commercial downstream routes and exclude laboratory-only esterifications or unverified solvent substitutions. Each scenario separates compliance instruments, feed ratios, production process boundaries, and terminal article classes.
In fixed-bed dehydration units processing TBA for polymer-grade isobutylene, the governing constraint is suppression of oligomer formation as the reaction mixture passes through the adiabatic hot spot. Commercial reactors charged with γ-Al2O3 extrudates of 3.0 mm diameter are operated at a hot-spot temperature of 250–310 °C and backpressure of 0.3–0.8 MPa. A water co-feed at a TBA:H₂O molar ratio of 1:0.5–1.0 displaces adsorbed tert-butyl carbonium ions from acid sites before dimerization to diisobutylene or trimerization to triisobutylene. Published plant data indicate TBA conversion above 99% and isobutylene selectivity of 96–99% at WHSV 1.0–3.0 h⁻¹. Catalyst bed pressure drop is monitored against the clean-bed baseline, and regeneration with diluted air is scheduled when differential pressure reaches site-specific limits, typically when coke accumulation prevents stable hot-spot control. Transfer piping upstream of the reactor must be heat-traced above 30 °C because TBA freeze-out at 25.7 °C produces slug flow in charged feed lines.
The crude isobutylene is then dried over 3A molecular sieves to ≤5 µL/L water and routed to a cryogenic copolymerization unit where isobutylene and isoprene are dissolved in methyl chloride at −95 °C and initiated with AlCl3. Feed isoprene content is set between 0.8 mol% and 2.5 mol% to control unsaturation for subsequent vulcanization. Compliance boundaries for this segment include ISO 2302 for butyl rubber evaluation, ASTM D3188 for IIR compounding and property measurement, and REACH (EC) No 1907/2006 for substance registration and downstream communication. Terminal finished product types are inner tubes, tire curing bladders, pharmaceutical stoppers, construction sealants, and polyisobutylene lubricant additives.
Acid-catalyzed liquid-phase oxidation of tert-butanol with hydrogen peroxide yields tert-butyl hydroperoxide, a peroxy-compound intermediate whose commercial handling is governed more by decomposition kinetics than by raw material stoichiometry. The batch charge is set at an H2O2:TBA molar ratio of 1.1–1.3:1, with sulfuric acid catalyst at 0.5–2.0 wt% of total charge, held at 45–65 °C for 2–4 h in a glass-lined reactor with PTFE gaskets and a dedicated pressure-relief system. After phase separation, the organic layer is washed with aqueous sodium sulfite to quench unreacted peroxide and neutralized with sodium hydroxide to pH 6.5–7.5. The product is stabilized as 70 wt% TBHP in water or 5.0 M TBHP in decane, with storage restricted to vented containers below 40 °C. Compliance requirements for this segment include CLP (EC) No 1272/2008 classification and labeling, UN 3109 organic peroxide type F transport controls, and OSHA 29 CFR 1910.119 process safety management at the peroxide synthesis boundary. In downstream emulsion polymerizations, TBHP is metered as a redox initiator into the aqueous soap phase of cold SBR or acrylic systems at 0.05–0.20 phr of monomer, where it provides initiating radicals at 5–10 °C. Terminal finished product types are styrene-butadiene rubber latices, acrylic polymer dispersions, cured unsaturated polyester articles, and crosslinked EPDM compounds.
Manufacturing-scale lyophilization of poorly water-soluble small-molecule active pharmaceutical ingredients uses tert-butanol as a sublimable cosolvent because its solid point of 25.7 °C permits crystalline solvent-phase freezing and its vapor-pressure profile supports primary drying without plasticizing the amorphous API phase. The cosolvent is incorporated at 5–50% v/v in Water for Injection before sterile filtration through 0.22 µm PVDF membranes; concentrations above 30% v/v require explosion-proof lyophilizer construction and condenser-rated solvent recovery because the closed-cup flash point is 11 °C. The filled vials are frozen to −45 °C, annealed at −20 °C for crystal ripening, and primary-dried under a chamber pressure of 10–30 Pa with shelf ramp from −20 °C to +20 °C.
Residual TBA control in lyophilized cakes is not a single-point drying problem: TBA can preferentially reside in amorphous regions of the cake where secondary drying below 10 Pa and shelf temperatures up to 40 °C are required to reduce headspace TBA below release limits. The vapor path from the vial to the condenser is designed with a minimum tube diameter and a solvent trap because TBA vapors can back-stream if the condenser becomes saturated; multi-batch campaigns at TBA levels above 30% v/v therefore require condenser defrost and solvent recovery between batches. Residual tert-butanol is determined by headspace gas chromatography with flame ionization detection against limits set by ICH Q3C and USP <467>, and batch release is governed by FDA 21 CFR 211.166 and EU GMP Annex 1. Terminal finished product types are lyophilized sterile injectable powders for reconstitution, small-molecule cytotoxic dosage forms, and lyophilized reference standards.
When conversion of tert-butanol to tert-butyl acetate is coupled to a nitrocellulose lacquer formulation, the technical target is substitution of a VOC-exempt oxygenated solvent into a high-solids or conventional lacquer without exceeding reducing-power requirements. The esterification step is run at an acetic acid:TBA molar ratio of 1.05–1.20:1 in the presence of an acid catalyst at 100–120 °C, with continuous removal of water to drive conversion; the distilled tert-butyl acetate is held to ≥99.5 wt% purity and ≤0.05 wt% water. In lacquer thinning, tert-butyl acetate is incorporated at 15–35 wt% of the total solvent cut and balanced with ethanol, isopropanol, and n-butyl acetate to maintain nitrocellulose solution viscosity. Compliance boundaries for the finished coating include US EPA 40 CFR 51.100(s) VOC exemption for tert-butyl acetate, SCAQMD Rule 102 for architectural and industrial coatings in the South Coast Air Quality Management District, and EU Directive 2004/42/EC for decorative paint VOC phase-in limits. Terminal finished product types include nitrocellulose wood lacquers, flexographic and gravure printing inks, heat-seal lacquers, and automotive refinish basecoats.
Sulfonic acid ion-exchange resin catalysts achieve para-directed alkylation of phenol with tert-butanol in continuous fixed-bed or stirred batch units operating between 80 °C and 120 °C. The phenol:TBA molar feed ratio is held at 1:1.2–2.2 to shift selectivity between 4-tert-butylphenol and 2,4-di-tert-butylphenol, while resin loading is maintained at 5–15 wt% of phenol to control exotherm and resin fouling. The resulting 2,4-di-tert-butylphenol is the alkylation precursor for tris(2,4-di-tert-butylphenyl) phosphite and benzotriazole UV stabilizers, which are compounded into polyolefin films, engineering thermoplastics, and lubricant antioxidant packages. Compliance in this segment is defined by FDA 21 CFR 178.2010 where the stabilizer is listed for food-contact polymer use, EU 10/2011 for plastic food-contact materials, and ASTM D943 for oxidation life of inhibited mineral lubricants. Terminal finished product types include polypropylene stabilization masterbatches, HDPE pipe compounds, automotive interior olefinic parts, and turbine/industrial lubricant additive packages.
Downstream of a TBA dehydration unit, high-purity isobutylene may be routed to a fixed-bed amination reactor where excess ammonia over an acidic zeolite yields tert-butylamine at 250–320 °C and 3.0–5.0 MPa. The NH₃:isobutylene molar feed ratio is set at 1.5–3.0:1 to suppress secondary amine formation and preserve catalyst cycle length. tert-Butylamine then reacts with 2-mercaptobenzothiazole under controlled oxidation with sodium hypochlorite or hydrogen peroxide at 30–50 °C to form N-tert-butyl-2-benzothiazolesulfenamide, a delayed-action accelerator. Compounding with natural rubber and synthetic polyisoprene uses the accelerator at 0.8–1.5 phr in tire tread and belt skim formulations. Compliance and testing boundaries include ASTM D412 for vulcanized rubber tensile, ISO 37 for stress-strain properties, and REACH (EC) No 1907/2006 for substance registration. Published plant-level catalyst deactivation data for this exact TBA-dehydration-to-tert-butylamine routing are limited; licensor-specific yield tables and the catalyst vendor’s minimum NH₃:isobutylene ratio must be applied during design. Terminal finished product types are tire tread compounds, conveyor belts, molded rubber goods, and vibration isolation mounts.
Competitive Tert-Butanol prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618136850665 or mail to admin@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8618136850665
Email: admin@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
tert-Butanol, CAS 75-65-0, also designated 2-methylpropan-2-ol and tert-butyl alcohol, is supplied as a clear liquid above its solidification range of 24 °C to 26 °C. The anhydrous product is characterized by a minimum purity of 99.5 wt% by split/splitless capillary gas chromatography with flame ionization detection, water content not exceeding 0.10 wt% by ASTM E203, acidity not exceeding 0.010 wt% as acetic acid by ASTM D1613, nonvolatile residue not exceeding 0.005 wt% by ASTM D1353, and a platinum-cobalt color of 10 Pt-Co maximum by ASTM D1209. Technical-grade material permits water up to 0.15 wt% and is reserved for solvent blending and process applications that do not involve moisture-sensitive chemistry. Liquid density is approximately 0.775 g/mL at 25 °C by ASTM D4052, the closed-cup flash point is 11 °C by ASTM D56, and the atmospheric boiling range is 81.5 °C to 83.5 °C by ASTM D1078.
| Parameter | Anhydrous specification | Test method |
|---|---|---|
| Purity | ≥99.5 wt% | Split/splitless capillary GC/FID |
| Water | ≤0.10 wt% | ASTM E203 |
| Acidity as acetic acid | ≤0.010 wt% | ASTM D1613 |
| Nonvolatile residue | ≤0.005 wt% | ASTM D1353 |
| Color | ≤10 Pt-Co | ASTM D1209 |
| Boiling range | 81.5 °C–83.5 °C | ASTM D1078 |
| Liquid density at 25 °C | 0.775 g/mL | ASTM D4052 |
| Closed-cup flash point | 11 °C | ASTM D56 |
Bulk transfer and storage are governed primarily by the high solidification point and the flammable liquid classification. Under 29 CFR 1910.106, tert-butanol falls into Class IB flammable liquid service because the closed-cup flash point is below 22.8 °C and the boiling point is above 37.8 °C. Storage tanks should be held at 30 °C to 35 °C with nitrogen blanketing at 5 kPa to 10 kPa gauge. Pump motors in classified areas should meet IEC 60079-0 and IEC 60079-11 or equivalent explosion-proof construction. Conservation vents should be set to 10 kPa positive and −0.5 kPa vacuum to prevent tank deformation during pump-out. Flame arresters should be tested to EN ISO 16852. The vapor pressure of approximately 5.5 kPa at 25 °C is sufficient to form flammable vapor mixtures above 11 °C, so bonding and grounding of transfer lines and receiving vessels are mandatory.
The nominal solidification range of 24 °C to 26 °C is the principal operational boundary in unheated plants. In 10,000-L stainless-steel storage vessels located in warehouses that fall below 20 °C, the product commonly solidifies at the bottom outlet and in the manway rim. Transfer pumps should be sealless magnetic-drive or canned-motor designs because mechanical seal chambers retain a static heel that can freeze during short shutdowns. Loading arms and meter skids should be heat-traced at 28 °C to 30 °C, not above 40 °C, because elevated temperature raises the vapor concentration in the headspace and increases breathing losses. Filtration of cold tert-butanol through 100-µm cartridge filters has been observed to blind rapidly when the temperature approaches 20 °C; filter housing jackets should therefore be maintained at 30 °C and purged with nitrogen before batch end. Freeze-thaw cycles do not degrade chemical identity, and solid material can be reliquefied by heating at 30 °C for 24 h with low-shear recirculation. However, repeated cycling in carbon steel storage is not recommended because condensed moisture on the frozen surface accelerates trace corrosion, particularly if the product contains dissolved carbon dioxide.
The same solidification behavior constrains washing and crystallization operations. A tert-butanol wash should not be dosed into an unjacketed filter dryer when the filter housing is below 22 °C. In pilot-scale agitated nutsche filters, local freezing at the wall reduces wash uniformity and leaves a residual heel that later dissolves into the next batch. The recommended procedure is to preheat the filter jacket to 30 °C and to verify wall temperature with a contact thermocouple before charging the alcohol. Once the product is liquid, it remains fully miscible with water, and the binary water/tert-butanol azeotrope at atmospheric pressure is approximately 79.9 °C at 88.2 wt% tert-butanol. This azeotropic behavior permits water removal in distillation stills, but the column reboiler must be sized for a liquid feed that can solidify in the condenser if cooling water is below 15 °C.
tert-Butanol is used as a reaction solvent where the absence of an α-hydrogen suppresses ordinary alcohol oxidation and alkoxide-mediated dehydrogenation pathways. In pharmaceutical esterification steps, the alcohol is charged at process-dependent molar excess, and the reactor is held between 40 °C and 60 °C in glass-lined equipment. The anhydrous specification is critical because residual water competes with ester formation and raises the equilibrium acid value. Water above 0.10 wt% by ASTM E203 is therefore a release-control parameter. In extractive workup, tert-butanol can be used as an azeotropic water removal aid, but the condensate receiver should be maintained above 20 °C if the water content is low, because the organic phase can solidify at the phase boundary and block the level sight glass. For cleaning formulations, tert-butanol is typically incorporated at 1 wt% to 5 wt% in solvent blends to adjust evaporation behavior. It is not suitable as a single-component room-temperature cleaning solvent in unheated lines because the pure material solidifies at average ambient conditions. Published data for this specific configuration is limited, but the solidification constraint is directly verified by the melting range and should be treated as a design limit rather than an additive-level variable.
In electronic cleaning service, the nonvolatile residue specification of 0.005 wt% by ASTM D1353 is used to qualify the material for evaporative drying on stainless-steel and glass substrates. Drying equipment should be operated at 30 °C to 35 °C with low-humidity nitrogen at a dew point below −20 °C to minimize water condensation on cold evaporation surfaces. tert-Butanol is fully miscible with water and with many hydrocarbons, but the water miscibility means that open drums exposed to humid air can absorb atmospheric moisture. Unused product in partially emptied drums should be blanketed with dry nitrogen and stored at 30 °C. The lower water solubility gap relative to n-butanol also changes phase-split predictions in extractive systems; n-butanol has a water solubility of approximately 7.7 g/100 g at 25 °C, whereas tert-butanol is miscible over the same range. This difference must be accounted for when replacing n-butanol in liquid-liquid extraction columns because the organic-phase water content and the raffinate alcohol content will shift.
The substitution of tert-butanol for isopropanol is not equivalent despite the similar atmospheric boiling point of 82.6 °C for isopropanol. Isopropanol remains liquid at −89 °C, while tert-butanol freezes in ordinary plant environments. The freezing point difference alone requires heated storage, heated filtration, and heated transfer piping that are unnecessary for isopropanol. However, tert-butanol is structurally resistant to oxidation to the corresponding ketone because the tertiary carbon lacks an α-hydrogen. Isopropanol can be oxidized to acetone by sodium hypochlorite and acetic acid at 0 °C to 15 °C, whereas tert-butanol does not follow that route. Sec-butanol is oxidized to methyl ethyl ketone under related conditions. This resistance may be exploited only when the process temperature is kept above the melting range; below 24 °C, any perceived oxidation advantage is negated by solidification in transfer lines and filter housings.
Compared with n-butanol, tert-butanol boils at approximately 82 °C rather than 117 °C and is miscible rather than partially miscible with water. These properties alter distillation cut points, condenser duty, and wastewater recovery. In formulations where n-butanol is used as a latent solvent, tert-butanol generally reduces the organic phase viscosity but may increase the water sensitivity of the blend. In reaction systems using acid catalysts, tert-butanol can form tert-butyl esters or tert-butyl ethers depending on substrate, temperature, and catalyst loading. The risk of forming a stable tert-butyl cation intermediate is higher than with primary alcohols, so the reaction should be evaluated for rearrangement and elimination byproducts. Gas evolution from isobutylene can occur under strongly acidic conditions above 40 °C; therefore, reactors should be vented to a relief system sized for isobutylene generation unless process safety testing shows otherwise.
Regulatory classification under the EU CLP mechanism includes flammable liquid category 3 with H226, acute inhalation toxicity category 4 with H332, serious eye irritation category 2 with H319, and specific target organ toxicity after single exposure category 3 with H335. These classifications apply to the pure substance and to mixtures above the relevant generic concentration limits under Regulation (EC) No 1272/2008. Safety-showers and eyewash stations should be accessible in unloading areas, and respiratory protection should be selected for organic vapor service when exposure may exceed national occupational exposure limits. Because the vapor is denser than air and can accumulate in pits, electrical area classification should include secondary containment and drain sumps near bulk storage.
The product is transferred into 160-kg steel drums, 800-kg intermediate bulk containers, or bulk stainless-steel tankers. For export shipments, the certificate of analysis should state the actual water content, acidity, residue, and color; buyers relying only on purity GC data may overlook moisture that interferes with downstream silylation, esterification, or organometallic chemistry. Incompatibility with strong oxidizing agents should be managed by separating the storage area from peroxides, chlorates, and nitric acid. tert-Butanol is not regarded as a peroxide-forming alcohol in the same class as diethyl ether, but accumulation of flammable vapor in confined spaces remains the dominant safety control. For process analytical work, online density measurement is less useful than temperature-corrected density because the liquid contracts as it approaches the solidification range. The product should therefore be sampled and tested after the storage tank temperature has been stabilized at 30 °C for at least 12 h to avoid sampling a partially frozen bulk.
