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DOTP, widely known by the abbreviation DOTP, scientifically referred to as bis(2-ethylhexyl) terephthalate (DEHT) in chemical literature, is a clear, colorless, almost odorless oily liquid organic compound with a high boiling point, produced by the esterification of terephthalic acid or dimethyl terephthalate (DMT) with 2-ethylhexanol.
Dioctyl Terephthalate is a phthalate-free primary (primer) ester plasticizer (softener) raw material in the polymer and vinyl industry.
Dioctyl Terephthalate is accepted as a direct alternative to traditional phthalate esters (DOP, DINP) particularly owing to its high compatibility with PVC (polyvinyl chloride) matrices, low volatility, excellent extraction resistance, superior electrical insulation properties, and the toxicological advantages brought by its phthalate-free structure.
DOTP is a functional component added to formulations in order to convert rigid and brittle polymer resins into processable, flexible, high-performance structures that are more sensitive to human health and the environment.
Dioctyl Terephthalate molecules penetrate between PVC polymer chains thanks to the para-positioned ester groups in the terephthalate structure, weakening interchain interactions and lowering the glass transition temperature (Tg) of the material.
Dioctyl Terephthalate-containing plastic, rubber, and coating systems acquire high flexibility, elongation capacity, excellent thermal stability, low migration, and smooth surface properties.
Dioctyl Terephthalate serves as a safe plasticizer in a very broad industrial spectrum ranging from toys to medical devices and hoses, from food packaging to cable insulations, from artificial leather to plastisols, floor coverings, and sealing gaskets.
Terephthalic acid bis(2-ethylhexyl) ester enables formulators to perform efficient, safe, and repeatable production thanks to its low cold-hardening tendency, high thermal stability, and superior performance in extrusion, injection, calendering, and coating processes.
Dioctyl Terephthalate is the fundamental terephthalate ester produced at high purity, presented at industrial standards, and most widely used in the global phthalate-free plasticizer market.
WHAT IS DOTP (DIOCTYL TEREPHTHALATE)?
DOTP is a diester compound obtained by the esterification of terephthalic acid (PTA) or dimethyl terephthalate (DMT), which are aromatic dicarboxylic acid derivatives, with 2-ethylhexyl alcohol, known in the chemical industry under the names Dioctyl Terephthalate, Bis(2-ethylhexyl) terephthalate, DEHT, or simply DOTP.
Terephthalic acid bis(2-ethylhexyl) ester is commercially presented in high purity as an anhydrous, clear, almost odorless, water-insoluble oily liquid form.
Dioctyl Terephthalate quality is determined according to specific technical parameters such as purity degree, ester content, acid value, color (Hazen/APHA), density, refractive index, volume resistivity, and water amount, and is selected according to the requirements of the application.
DEHT is an extremely effective phthalate-free plasticizer that ensures polymer gelling on PVC extrusion, calendering, and plastisol lines, increases melt fluidity, and exhibits low volatility during processing procedures.
Dioctyl Terephthalate also possesses a wide usage area as a component meeting human health compliance requirements in medical tubes, childcare products, food packaging films, cable jackets, gasket, and adhesive formulations.
DEHT provides low migration and high physical performance in polymer matrices owing to the symmetrical para-ester groups in its molecular structure.
COMMON PRODUCT AND CHEMICAL NAMES:
Dioctyl Terephthalate
DOTP
Bis(2-ethylhexyl) terephthalate
DEHT
Terephthalic acid bis(2-ethylhexyl) ester
1,4-Benzenedicarboxylic acid, bis(2-ethylhexyl) ester
Di(2-ethylhexyl) terephthalate
Dioctil Tereftalat
Di(2-etilheksil) tereftalat
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION
Product name: Dioctyl Terephthalate / Dioctil Tereftalat
Common abbreviation: DOTP / DEHT
Chemical name: Bis(2-ethylhexyl) terephthalate
Molecular formula: C₂₄H₃₈O₄
Molecular weight: 390.56 g/mol
CAS No: 6422-86-2
EC / EINECS No: 229-176-9
Chemical class: Aromatic Terephthalate Ester / Phthalate-Free Plasticizer
Main functions: Primary phthalate-free PVC plasticizer, flexibility and elongation enhancer, low migration provider, electrical insulation regulator, thermal stability enhancer
Terephthalic acid bis(2-ethylhexyl) ester is a primary terephthalate ester having a defined chemical structure, exact molecular formula, and fixed molecular weight, not in the ortho-phthalate structure.
Dioctyl Terephthalate has CAS No 6422-86-2 and EC No 229-176-9 defined in global inventories, REACH registrations, and official chemical indexes.
Dioctyl Terephthalate industrial grades typically have an ester purity specified as minimum 98.5% - 99.0% and possess very low acidity and moisture content.
PHYSICAL AND CHEMICAL PROPERTIES
Dioctyl Terephthalate is generally a clear, colorless to very pale yellowish oily liquid.
Physical appearance: Clear oily liquid
Boiling point: Approximately 387 °C (under 760 mmHg pressure)
Melting / Freezing point: Approximately -48 °C - -50 °C
Density: Approximately 0.982 - 0.985 g/cm³ at 20 °C
Solubility in water: Practically insoluble in water (< 0.1 mg/L at 25 °C); fully miscible in organic solvents and mineral oils
Flash point: Approximately 210 °C - 235 °C (closed cup)
Refractive index (n20/D): Approximately 1.486 - 1.490
Viscosity: Approximately 65 - 80 mPa.s (cP) at 20 °C
Volume resistivity: Minimum 1 x 10¹¹ ohm.cm at 20 °C (in cable grades)
HOW DOES DIOCTYL TEREPHTHALATE WORK AT THE MOLECULAR LEVEL?
Terephthalic acid bis(2-ethylhexyl) ester acts like a physical softener and flexibility provider within the polymer matrix by interacting with polymer chains.
Dioctyl Terephthalate molecules disrupt the tight arrangement of the rigid polymer structure by settling between the polymer chains of PVC and reduce interchain friction.
DOTP presence increases the free volume and mobility of polymer segments, elevating the stretchability, impact resistance, and processability of the material.
Dioctyl Terephthalate separates from the polymer matrix more difficultly compared to ortho-phthalates due to its para-positioned ester structure and exhibits lower extraction in contact with water, soapy solutions, or oily environments.
WHICH INDUSTRIES IS IT USED IN?
Children's toys, baby care products, and flexible vinyl goods manufacturing
Medical devices, blood bags, catheter, and blood tubing production
Food packaging films, stretch films, and gasket systems
PVC cable, wire insulation, and high temperature resistant sheath production
Artificial leather, shoe sole, boot, and injection-grade flexible PVC goods
Hose, profile, sealing gaskets, and transparent tube manufacturing
PVC plastisol, floor coverings, wallpaper, tarpaulin, and tent coatings
Synthetic rubbers, adhesives, and sealing mastics
THINGS TO CONSIDER DURING USE
DOTP should be used by taking general occupational safety precautions, and direct skin and eye contact should be avoided.
Dioctyl Terephthalate should be stored in cool, dry, well-ventilated areas, away from direct sunlight and heat sources, in tightly closed original containers.
DOTP gelling temperature in formulations can be slightly higher compared to DOP, therefore process temperature or process aids should be optimized according to need.
ADVANTAGES OF DIOCTYL TEREPHTHALATE (DOTP) COMPARED WITH ALTERNATIVE PLASTICIZERS
Dioctyl Terephthalate (DOTP), also known as Di(2-ethylhexyl) Terephthalate (DEHT), is a non-ortho-phthalate plasticizer widely used in flexible polyvinyl chloride (PVC) applications.
Dioctyl Terephthalate (DOTP) is an alternative to conventional plasticizers such as DOP (DEHP) and is valued for its good plasticizing performance, low volatility, electrical properties, and flexibility at low temperatures.
1) Non-Ortho-Phthalate Structure: One of the main advantages of DOTP is its chemical structure, which differs from that of DEHP, commonly known as DOP.
This makes DOTP a suitable alternative for applications where ortho-phthalates are restricted or where customer specifications require non-ortho-phthalate plasticizers.
However, being a non-ortho-phthalate does not automatically mean that DOTP is suitable for every regulated application or completely risk-free.
2) Good Plasticizing Efficiency and Processability: DOTP improves the softness and flexibility of PVC and is suitable for manufacturing flexible PVC compounds.
It offers good processing characteristics in properly designed formulations and can be used in cable insulation, hoses, synthetic leather, and flooring applications.
3) Low Volatility: DOTP is suitable for PVC applications requiring low volatility. This property can help reduce plasticizer losses during processing and service.
Actual performance depends on temperature, formulation, and operating conditions.
4) Flexibility at Low Temperatures: DOTP helps maintain flexibility at low temperatures in suitable PVC formulations.
This is particularly important for cable coatings, hoses, and flexible PVC components.
However, low-temperature performance varies depending on the resin and other formulation ingredients.
5) Electrical Properties: DOTP's electrical insulation characteristics make it suitable for certain wire and cable formulations.
The electrical performance of the finished product depends on the entire formulation and manufacturing conditions, not solely on the plasticizer.
6) Wide Range of Industrial Applications: DOTP is used in wire and cable coatings, PVC compounds, synthetic leather, hoses, footwear soles, flooring, and coated fabrics.
Its broad application range makes Dioctyl Terephthalate (DOTP) a valuable option for manufacturers producing different types of flexible PVC products.
COMPARISON OF DOTP WITH DOP AND OTHER ALTERNATIVES
DOTP's main advantage is its combination of a non-ortho-phthalate structure and good plasticizing performance. DOP (DEHP) may offer lower costs or lower plasticizer requirements in certain formulations. Alternatives such as DINP and DIDP provide different durability and processing characteristics depending on the application.
Adipates and other specialty plasticizers may also be preferred when specific low-temperature or performance requirements apply.
Therefore, DOTP cannot be considered superior to every alternative in every technical aspect.
CONCLUSION
DOTP is a strong alternative to conventional plasticizers because of its non-ortho-phthalate structure, good compatibility with PVC, low volatility, and suitability for a wide range of industrial applications. The final selection should be based on technical performance, cost, intended application, and applicable regulatory requirements.
TECHNICAL SUMMARY
Dioctyl Terephthalate, with the short name DOTP, is the fundamental terephthalate ester plasticizer offering high flexibility, low migration, and phthalate-free safe usage in the vinyl and polymer industry.
Dioctyl Terephthalate is one of the indispensable raw materials of the modern plastic chemistry market with its high purity, superior electrical insulation, profile suitable for human health, and wide industrial application area.
CONTACT ATAMAN KIMYA
For further information and inquiries regarding this chemical, please contact Ataman Kimya.
