Di-2-ethylhexyl adipate

What Is DOA?

Di-2-ethylhexyl adipate (dioctyl adipate, DOA; CAS 103-23-1) is the diester of adipic acid and 2-ethylhexanol. It is a colorless, transparent, oily liquid with a slight odor, insoluble in water but soluble in organic solvents such as ethanol, ether and acetic acid. Typical assay is 99.5% with water below 0.1%. Its claim to fame is simple and durable: DOA is the classic cold-resistant plasticizer, the ester that keeps soft PVC supple when everything else has gone stiff.

Ester Chemistry and Why It Performs

DOA’s linear adipate chain with branched 2-ethylhexyl end groups gives a low glass-transition contribution and low crystallinity — polymer chains keep moving at temperatures where phthalate-plasticized PVC has frozen into brittleness. Practically, DOA-plasticized compounds retain flexibility down to roughly −40 ℃, with high plasticizing efficiency, minimal discoloration on heating, good light stability and a pleasant soft hand feel. Its trade-offs: higher volatility and extraction sensitivity than polymeric plasticizers, and lower oil resistance than phthalates — which is why DOA is frequently used as a cold-flexibility modifier blended into a primary plasticizer system rather than alone.

Applications in Depth

Cold-Climate and Freezer-Grade PVC

Freezer-door gaskets and hoses, cold-room curtains, winter tarpaulins, outdoor cables in arctic service and ski-glove coatings all rely on DOA fractions (often 10–30 phr over a primary plasticizer) to hold flexibility at deep low temperature. Compounders verify with Clash-Berg cold-flex and brittleness-point testing; DOA shifts those curves further down than almost any common monomeric ester.

Food-Contact Films

DOA is a traditional plasticizer for food-wrap PVC film — cling films for meat and produce — where its low taste and odor and regulatory acceptance (subject to jurisdiction-specific migration limits) made it the industry standard for decades. Food-pack users must confirm current compliance for their markets and build migration testing into qualification.

Coated Fabrics and Artificial Leather

Coating formulations for upholstery, banner materials and footwear uppers add DOA to keep surfaces supple in winter transport and unheated retail environments, where phthalate-only systems would crack on folding.

Cellulosic Coatings and Lacquers

Nitrocellulose and ethyl cellulose lacquers use DOA as a plasticizer that prevents film brittleness over temperature swings — wood coatings, paper coatings and specialty varnishes.

Synthetic Rubbers and Lubricant Esters

Nitrile and chloroprene rubber compounds gain low-temperature flexibility from DOA; as a diester base fluid it also appears in synthetic lubricants and greases engineered for cold climates.

Blending Strategy: DOA with DOTP, DOP and DINP

In practice most recipes are teams: a primary general-purpose plasticizer (classically DOP, increasingly DOTP or DINP) provides permanence, cost and heat stability; DOA contributes the low-temperature window. A 15–25 phr DOA share typically restores deep-cold flexibility lost when converting legacy phthalate systems to modern primary plasticizers. This split — primary for permanence, DOA for cold — is the working pattern our technical service team supports with starting formulations.

Packaging, Logistics and Lead Time

Blue-painted steel drums of 190 kg net (18 kg tare), 920 kg IBC totes (56.5 kg tare), or 22-ton flexitanks loaded into 20-foot containers. Shipping typically 6–10 business days after payment confirmation, with per-batch COA covering assay, acid value, water, color and volume resistivity. As a non-regulated liquid, DOA moves without dangerous-goods paperwork, simplifying export documentation.

Handling and Storage

Store in sealed drums or tanks in dry, ventilated areas away from strong oxidizers; avoid prolonged heat that slowly raises acid value. Shelf life 24 months typical. Standard PPE for chemical handling per the SDS; DOA is low-toxicity and non-irritating in normal industrial contact.

How DOA Is Produced

DOA is manufactured by direct esterification: adipic acid reacts with a stoichiometric excess of 2-ethylhexanol under acid catalysis, water of reaction is continuously removed (azeotropically with the excess alcohol), and the crude ester is neutralized, washed, stripped of excess 2-EH under vacuum, and polish-filtered. Product quality concentrates in three controls: end-point acid value (residual acid degrades PVC heat stability), excess-alcohol removal (odor and volatility), and color protection during the thermal cycle (air exclusion and short residence). Because EastChem also supplies the 2-ethylhexanol feedstock, the adipate chain can be audited end-to-end within one quality system.

Testing Cold Flexibility: What the Numbers Mean

Compounders qualify cold-flexibility with three standard measurements. Clash-Berg torsional stiffness reports the temperature at which the compound’s apparent modulus reaches 3,140 kg/cm2 — the industry “Tf” figure; DOA-modified compounds push Tf 10–20 degrees lower than phthalate-only baselines. Brittleness point (impact at low temperature) catches the cliff edge of flexibility. Gehman stiffness spectra map the whole softening curve. When a supplier substitution or new lot shifts these numbers, the usual culprits are assay drift, acid value or moisture — all COA-visible parameters, which is why the COA belongs in the formulation file, not a drawer.

Regulatory Notes for Food-Contact Uses

DOA’s food-contact acceptance is jurisdiction- and application-specific: classical approvals exist for flexible PVC food wrap in several major jurisdictions, subject to specific migration limits into fatty foods in particular. Compliance engineering therefore runs on migration modeling and confirmatory testing of the finished film in its real use, with the supplier providing supporting purity documentation (phthalate cross-contamination statements increasingly requested alongside, as trace phthalates from shared plants can void a food program). Buyers should maintain the compliance file per market and re-trigger it on any change of plasticizer source — a process our technical team supports with documentation per lot.

Storage Quality Drift and How to Prevent It

Stored warm and half-open to humid air, DOA slowly gains water and can creep in acid value; stored properly — sealed, below 35 ℃, away from oxidizers — it holds specification for two years and more. Practical receiving QA: verify drum seals intact, check COA date against arrival, and for critical programs run a quick acid-value and color confirm on arrival for lots older than twelve months in any supply chain leg. These five-minute checks prevent the classic failure mode: a winter-production emergency traced to plasticizer that sat in a hot customs yard for a summer.

Frequently Confused: DOA vs DOS vs DOZ

Three cold-flexibility esters trade side by side and are regularly confused on paper. DOA (adipate, C6 diacid) is the volume standard — best cost-performance for deep-cold flexibility. DOS (sebacate, C10 diacid) extends cold performance further and improves oil resistance at notably higher cost. DOZ (azelaate, C9) sits between them on both axes. Selection logic: choose DOA unless the application’s temperature floor or oil-contact reality pushes to DOS/DOZ pricing. A second caution: dioctyl-adipate style abbreviations collide across ester families — always contract by CAS 103-23-1 to eliminate ambiguity.

Ordering and Lead-Time Planning

Because DOA pairs with primary plasticizers in most recipes, the efficient purchase is the pair: DOA plus DOTP (or your primary of choice) on one order, one container, one document set — with drum counts sized to the phr ratio in your formulation so neither component outruns the other in inventory. EastChem’s 6–10 day shipping window supports seasonal build-ups ahead of northern-hemisphere winter demand, and standing quarterly programs smooth the price and production cycle for both ester plants.

Why Source DOA from Dongying EastChem

Specialized in the chemical industry for 19 years across three subsidiaries: high product purity, stable batch quality, strict delivery discipline and professional service. The adipate chain sits naturally inside our plasticizer family — consolidate DOA with its feedstock 2-ethylhexanol, with DOTP for the primary-plasticizer slot, and with glycols for the compound-side water phase. MOQ one 20-foot container, samples about 2 days, T/T or L/C.

About this guide: cold-flexibility comparisons and handling notes reflect typical compounded-PVC practice and our DOA supply specifications. Migration and food-contact compliance are jurisdiction-specific and must be verified for each market. Ester comparisons, testing context and regulatory notes are maintained as specifications and market requirements develop, with the delivered COA governing each lot. Compounders running cold-service programs can request starting formulations, migration-supporting documentation for food-contact review, and the paired supply of DOA with DOTP and 2-ethylhexanol consolidated in single containers. Technical teams preparing a winter-grade compound for the first time usually start from a reference recipe, run Clash-Berg and brittleness confirmation on their own press output, and lock the blend ratio into the work order — and our desk supports each step with the data and samples needed to move from trial to production within a single season window. Reference cold-flexibility data sheets and drum-count consolidation plans accompany every quotation, together with the shipping schedule for the coming season.

Contact for quotations and samples:
Carrie Sun
TEL / WhatsApp: +86 183 5460 8228
Email: [email protected]