Types of PVC Plasticizers and Formulation Design: A Selection Guide for Laboratory and Production

Polyvinyl chloride (PVC) is a widely used general-purpose thermoplastic resin that combines good mechanical strength, chemical resistance, electrical insulation, and a certain level of flame retardancy. By adjusting additives such as plasticizers, stabilizers, and fillers in the formulation, PVC can be processed into rigid products (pipes, profiles, sheets) as well as flexible products (electrical cables, films, artificial leather, hoses, and many others).

Among these additives, the plasticizer is the key to converting “rigid PVC” into “flexible PVC”: it determines the material’s flexibility, low-temperature performance, electrical properties, and long-term service life. Plasticizers with different molecular structures show significant differences in compatibility, plasticizing efficiency, cold resistance, heat resistance, flame retardancy, and safety. Therefore, in both education and industrial practice, how to select and use plasticizers appropriately for a given application scenario is a critical topic in PVC formulation design.

Among the many polymer resins, PVC exhibits relatively good compatibility with plasticizers and is one of the most typical and widely used plasticizable resins. This article therefore focuses on the types, properties, and selection of plasticizers for PVC.

What Is a Plasticizer and What Does It Do in PVC?

Plasticizers are an important class of additives in plastic formulations. Their primary function is to lower the glass transition temperature (Tg) and brittleness temperature of polymers, turning the material from “hard and brittle” into “soft and tough.”

Taking PVC as an example, adding an appropriate amount of plasticizer can achieve:

1. Advantages (desired effects)

(1) Increased flexibility and elongation at break

(2) Improved low-temperature performance and reduced brittleness temperature

(3) Better processing flowability and reduced melt viscosity

2. Trade-offs that must be accepted

(1) Reduced hardness and modulus

(2) Lower heat distortion temperature and Martin heat resistance temperature

(3) Potentially higher volatility, migration, and extractability (depending on the type of plasticizer)

Common PVC Plasticizers by Structural Type and Representative Aladdin Products

The following table lists representative PVC plasticizers organized by chemical structural type. You can understand the characteristics of different plasticizers from a “structure–property” perspective, or directly look up detailed technical information and test data on the Aladdin website using the CAS number or catalog number.

Structural type	Typical abbreviation	English name	CAS No.	Representative Aladdin Cat. No.	Grade / Purity	Main features	Typical PVC application examples
Phthalates	DMP	Dimethyl phthalate	131-11-3	D103466	Chemical pure (CP) ≥99%	High plasticizing efficiency; relatively high volatility; mainly used in cellulose resins and as a secondary plasticizer in PVC	Cellulose resin films and coatings; minor use in PVC and nitrile rubber, etc.
Phthalates	DEP	Diethyl phthalate	84-66-2	D108216	AR ≥99.5%	Lower volatility; average low-temperature performance	Cellulose acetate films, clear varnishes; auxiliary plasticizer in some PVC products
Phthalates	DBP	Dibutyl phthalate	84-74-2	D103473	Moligand™ Standard for GC ≥99.5% (GC)	High plasticizing efficiency; relatively high volatility and extractability; poor durability	Traditional flexible PVC products, nitrocellulose lacquers, etc. (now heavily restricted and gradually reduced in use)
Phthalates	DOP / DEHP	Bis(2-ethylhexyl) phthalate / Dioctyl phthalate	117-81-7	D109648	AR ≥99%	Classical general-purpose primary plasticizer with well-balanced performance and good compatibility	Various flexible PVC products such as films, artificial leather, cable compounds, hoses, etc. (increasingly being replaced due to environmental regulations)
Phthalates	DnOP	Di-n-octyl phthalate (DNOP)	117-84-0	D108623	Standard for GC ≥99% (GC)	Better low-temperature performance and lower volatility than DOP; higher cost	Historically used in certain flexible PVC products and cable compounds. Strongly affected by regulations on toys, childcare articles, and food-contact materials; largely replaced in high-safety applications. Regulatory compliance for the target market must be carefully checked before use.
Phthalates	DINP	Diisononyl phthalate	28553-12-0 (mixture of isomers)	D111291	≥99% mixture of branched-chain isomers	General-purpose, environmentally friendlier replacement primary plasticizer; low volatility; low migration; lower toxicity than DOP	General flexible PVC such as toy films, wires and cables, hoses, footwear materials, etc.
Phthalates	DIDP	Diisodecyl phthalate	26761-40-0	D105348	≥99% (GC) mixture of isomers	Good heat resistance and durability; excellent extraction resistance; suitable for heat-resistant cables	70–90 °C heat-resistant cable compounds, automotive wire harnesses, weather-resistant flexible products
Ortho-/para-phthalates	DOTP / DEHT	Dioctyl terephthalate	6422-86-2	D107571	≥97%	“Non-phthalate” (non-ortho-phthalate) environmental plasticizer; good heat resistance; low volatility	Environmentally friendly flexible PVC, cable compounds, artificial leather, flooring, etc.
Aliphatic dicarboxylates	DOA	Bis(2-ethylhexyl) adipate / Dioctyl adipate	103-23-1	B103070	≥99%	Typical cold-resistant plasticizer; excellent low-temperature flexibility	Cold-resistant soft films, frozen food packaging films, cable compounds for cold regions, etc.
Aliphatic dicarboxylates	DIDA	Diisodecyl adipate	27178-16-1	D196241	Reagent Grade	Superior low-temperature properties; low volatility; good durability	High-performance cold-resistant cable compounds, automotive wiring harnesses, low-temperature flexible products
Aliphatic dicarboxylates	DOS	Bis(2-ethylhexyl) sebacate / Dioctyl sebacate	122-62-3	B105168	Standard for GC ≥98.5% (GC)	Excellent cold resistance (very high low-temperature flexibility); outstanding electrical properties	Aerospace cables, military cables, high-end cold-resistant PVC products
Aliphatic dicarboxylates	DOZ	Bis(2-ethylhexyl) azelate / Azelaic acid di(2-ethylhexyl) ester	103-24-2	B153098	≥98% (GC)	High-performance cold-resistant plasticizer; good compatibility with PVC and many other resins; low viscosity and high boiling point; high plasticizing efficiency; low volatility and migration; good heat stability, light stability, and electrical insulation; better cold resistance than DOA	Cold-resistant flexible PVC products such as artificial leather, films, sheets, cable jackets, plastisols; PVC automotive parts requiring good low-temperature flexibility and electrical properties
Trimellitates	TOTM	Tris(2-ethylhexyl) trimellitate	3319-31-1	T107253	≥97%	High heat resistance; low volatility; excellent migration resistance; superior long-term thermal aging performance	90–105 °C heat-resistant cable compounds, high-temperature flexible cords, soft PVC for electrical applications
Polyester plasticizers	PEA (Poly(ethylene adipate))	Poly(ethylene adipate)	24938-37-2	P341826	Molecular weight ~1000	Excellent non-migrating behavior, extraction resistance, and oil resistance; low volatility; significantly improves the long-term heat resistance and durability of flexible PVC; relatively high viscosity and medium-to-low plasticizing efficiency; usually used together with monomeric plasticizers	Non-migrating / high-durability flexible PVC systems such as high-performance cable jackets, automotive interior parts, oil-resistant hoses, sealing profiles, etc.
Phosphate esters	TPP	Triphenyl phosphate	115-86-6	T108609	Analytical standard ≥99.8% (GC)	Typical flame-retardant plasticizer; moderate plasticizing performance; imparts good flame retardancy	Flame-retardant PVC, cable compounds, coating layers, and flame-retardant systems in engineering plastics
Phosphate esters	TCP	Tricresyl phosphate	1330-78-5	T109729	≥99%	Flame-retardant, wear-resistant, weather-resistant; serves both as plasticizer and flame retardant	Cable compounds, conveyor belts, coating materials, flame-retardant flexible PVC
Phosphate esters	TBP	Tributyl phosphate	126-73-8	T100709	Standard for GC ≥99.5%	Strong solvating power; moderate plasticizing ability; commonly used as a cosolvent/co-plasticizer	Special PVC formulations, extraction agents, synergistic component in some flame-retardant systems
Phosphate esters	TOP	Tris(2-ethylhexyl) phosphate	78-42-2	T104035	≥99%	Provides both flexibility and flame retardancy; low volatility	Flame-retardant cable compounds, flexible cords, flame-retardant flexible films, etc.
Phosphate esters	IPPP	Isopropylated triphenyl phosphate	68937-41-7	I304396	P 8.3–8.5%; viscosity 48–63 mPa·s (25 °C)	Halogen-free flame-retardant plasticizer; good compatibility; low smoke and low toxicity	Environmentally friendly flame-retardant cable jackets, flooring materials, flame-retardant PVC coatings, etc.
Epoxides	ESO	Epoxidized soybean oil	8013-07-8	E107074	Chemical pure (CP)	Non-toxic or low-toxicity; functions both as plasticizer and co-stabilizer; good heat and weather resistance	Non-toxic PVC, food packaging films, medical tubing, children’s toys, etc.
Epoxides	ELO	Epoxidized linseed oil	8016-11-3	–	–	High epoxy value and good stability; acts as both plasticizer and stabilizer	Weather-resistant PVC products, coatings, cables, etc. (often used together with ESO or other primary plasticizers)
Fatty acid esters	BO	Butyl oleate	142-77-8	B112694	≥70%	Good flexibility and strong lubricity; improves processing flow	Auxiliary plasticizer and lubricant–plasticizer in flexible PVC products
Fatty acid esters	–	Butyl stearate	123-95-5	B102989	≥96% total ester content	Excellent lubricity; improves surface gloss and processability	Used as a lubricating plasticizer in cable compounds, films, and artificial leather
Citrates	TBC	Tributyl citrate	77-94-1	T105179	≥98%	Non-toxic/low-toxicity; good low-temperature performance; medium plasticizing efficiency	Food-contact packaging, medical PVC, children’s toys, tablet coatings, etc.
Citrates	ATBC	Acetyl tributyl citrate	77-90-7	T111251	≥97%	Low migration; excellent combined resistance to heat, light, and water	High-end non-toxic PVC, medical tubing, blood bags, food packaging, toys, etc.
Chlorinated plasticizers	CP-42	Chlorinated paraffin-42	63449-39-8	C301618	Chlorine content: 42%	Flame-retardant, plasticizing, low cost; reduces overall formulation cost but has relatively high migration and noticeable odor	Flame-retardant cable compounds, shoe soles, artificial leather, rubberized fabrics, etc. (used in combination with primary plasticizers)
Chlorinated plasticizers	CP-52	Chlorinated paraffin-52	63449-39-8	C301625	Chlorine content: 52%	Stronger flame retardancy; good electrical insulation; low volatility	Flame-retardant cable compounds, conveyor belts, mining cable jackets, etc.
Other new plasticizers	DINCH	Diisononyl cyclohexane-1,2-dicarboxylate	166412-78-8	D298750	≥95%	Non-phthalate; low migration and low volatility; favorable toxicological profile; suitable for high-safety applications	Medical PVC, food-contact materials, children’s toys, wires and cables, and other demanding applications

Note: Chlorinated plasticizers (especially short-chain chlorinated paraffins) have been listed or proposed for listing as persistent organic pollutants (POPs). They should be used with caution or replaced by alternative systems in toys, consumer products, and applications with high environmental requirements.

Comparison of Plasticizer Performance: Efficiency, Durability, and Safety

In PVC applications, the following dimensions usually need to be considered together:

1. Plasticizing efficiency

(1) General trend:

Under comparable conditions, the empirical order of plasticizing efficiency is approximately:

certain low-molecular-weight phthalates > high-carbon phthalates ≈ citrates > aliphatic dicarboxylates > trimellitates, polyesters

(2) The higher the efficiency, the lower the dosage required to achieve the same hardness/flexibility. However, volatility and migration also tend to increase accordingly.

2. Migration, extraction resistance, and volatility

(1) Polyester plasticizers, trimellitates, and some high-carbon phthalates offer the best resistance to extraction and volatilization;

(2) Aliphatic dicarboxylates, some citrates, and low-carbon phthalates are relatively more prone to migration.

3. Water, oil, and chemical resistance

(1) High-molecular-weight polyesters and trimellitates generally perform better;

(2) Certain aliphatic dicarboxylates and citrates are more easily extracted in polar solvents or oils.

4. Safety and toxicology

(1) Particular attention must be paid to regulatory restrictions on phthalates, as well as potential concerns regarding short-chain chlorinated paraffins and certain phosphate esters;

(2) Common non-phthalate, low-toxicity plasticizers include citrates, selected fatty acid esters, polyesters, and epoxidized vegetable oils, but the latest regulations and certifications should always be consulted.

In practice, it is advisable to treat plasticizing efficiency, durability, and safety as three main design axes, and make trade-offs based on the specific service conditions of the final product.

Plasticizer Dosage and Formulation Essentials in PVC

1. Basic dosage ranges and property trends

Rigid PVC

(1) The plasticizer dosage is generally controlled at 0–5 phr (based on 100 phr resin), mainly to improve processing flowability.

(2) At low plasticizer levels (around 5–10 phr), tensile strength may sometimes exhibit a small peak; with further increases, overall strength and modulus decrease significantly.

Flexible PVC

(1) The total plasticizer dosage typically falls in the range of 26–60 phr. In ultra-soft or plastisol systems, the dosage may exceed 60 phr, but must be evaluated against mechanical and electrical performance requirements. The exact level depends on the target hardness and the type of plasticizer used.

(2) As plasticizer dosage increases:

(a) Flexibility and elongation at break ↑

(b) Hardness, modulus, Martin heat resistance temperature, and creep resistance ↓

(3) In practice, Shore hardness, volume resistivity, Martin heat resistance temperature, and low-temperature brittleness temperature are commonly used as key indicators to assess whether the plasticizer level is appropriate.

2. Plasticizer Selection and Dosage for Different Application Scenarios

Application scenario	Recommended plasticizer system (example)	Typical total plasticizer dosage range	Formulation / selection notes
General flexible products (hoses, artificial leather, flooring, etc.)	High-carbon phthalates (DINP/DIDP) or terephthalates (DOTP) as the primary plasticizers; small amounts of DOA / epoxidized vegetable oil can be added	30–50 phr	General-purpose flexible PVC formulations focus on balanced performance and cost. Small additions of epoxidized soybean oil can improve heat stability. When cost reduction is required, chlorinated paraffins, petroleum-based plasticizers, etc. may be introduced as auxiliary plasticizers, but attention must be paid to odor, migration, and aging behavior.
Cold-resistant flexible products (cold-room strip curtains, low-temperature hoses, cables for cold regions)	High-carbon phthalates / DOTP + aliphatic dicarboxylates (DOA, DOS, DOZ, etc.)	30–50 phr (cold-resistant plasticizers can account for 20–50% of the total)	Low-temperature flexibility is improved by increasing the proportion of DOA/DOS/DOZ. DOS offers the best cold resistance, but cost and compatibility must be balanced. Volume resistivity and mechanical strength retention at low temperatures should be monitored. Epoxidized plasticizers can be used as auxiliaries to enhance heat and aging resistance.
Non-toxic / environmentally friendly products (toys, food-contact items, medical tubing, etc.)	Citrates (TBC, ATBC) + fatty acid esters + polyester plasticizers + epoxidized vegetable oils (ESO, ELO)	30–50 phr	Avoid restricted phthalates, short-chain chlorinated paraffins, and certain high-risk phosphate esters. During selection, priority should be given to regulatory compliance and migration behavior. It is not advisable to pursue “phthalate-free” alone while neglecting long-term durability (e.g., fogging, cracking).
Cable sheathing compounds (70 °C rating, general / cold-resistant)	Primary plasticizers: DINP/DIDP/DOTP; for cold-resistant grades add DOA/DOS; for flame-retardant grades add small amounts of phosphate esters + chlorinated paraffins	30–50 phr (cold-resistant plasticizer typically around 5 phr, adjustable)	Typical formulation: plasticizer 30–50 phr, stabilizer 6–8 phr, lubricant 1.5–2 phr, filler 10–20 phr. General sheathing focuses on mechanical strength and weatherability. For cold-resistant or flame-retardant grades, adjust the levels of aliphatic dicarboxylates, phosphate esters, and chlorinated paraffins while maintaining electrical performance.
Cable insulation compounds (high insulation, 70–90 °C)	Primary plasticizers: trimellitates (TOTM) + polyester plasticizers; small amounts of high-carbon phthalates (DINP/DIDP) can be added to improve processability	40–50 phr	Typical formulation: plasticizer 40–50 phr, stabilizer 6–8 phr, lubricant 1–1.5 phr, filler ~10 phr. Key metrics are volume resistivity and long-term heat resistance. Primary plasticizers should be based on TOTM + polyesters. Phosphate esters are not recommended as main plasticizers in high-insulation formulations and should only be used in small amounts in flame-retardant insulation compounds.
High-temperature cable compounds (90 °C, 105 °C)	90 °C: high-carbon phthalates (e.g., C10/C12 esters) + partial trimellitates; 105 °C: predominantly TOTM + polyester plasticizers	40–50 phr	Higher levels of stabilizers are required, in combination with antioxidants and light stabilizers. The higher the temperature rating, the more the formulation relies on trimellitate + polyester systems. High-carbon phthalates are mainly used to improve processability and balance cost.
Transparent flexible PVC (transparent films, clear cables)	High-purity phthalates / terephthalates (e.g., DOTP) and specific polyester plasticizers; used together with organotin or other transparent stabilizers	30–45 phr	Compatibility and purity have a critical impact on transparency. Lubricant dosage must be tightly controlled to avoid increased haze or exudation. Fillers are usually minimized or omitted.
Non-migrating flexible products (non-migrating cables, wallcoverings, flooring, etc.)	Polyester plasticizers + trimellitates (e.g., TOTM) as the core system; high-carbon phthalates used only as minor auxiliaries	35–55 phr	The focus is on extraction resistance, volatility resistance, and long-term stability. These systems are commonly used in long-life applications, in contact with oils, or where plasticizer migration is critical. Lower plasticizing efficiency and higher processing viscosity must be accepted.
High-insulation flexible products (high-insulation cables, specialized insulation materials)	TOTM + polyester plasticizers; fillers selected from high-resistivity materials such as calcined kaolin and alumina	40–50 phr	Control metallic impurities, polar additives, and moisture content. Reduce additives that significantly lower volume resistivity where possible. If necessary, further increase the proportion of polyesters to reduce migration and dielectric loss.

Notes:

1. The dosage ranges in this table are typical reference values based on 100 phr PVC resin. Actual formulations should be adjusted according to the specific PVC K value, plasticizer type, downstream standards, and experimental data.

2. During selection, priority should be given to regulatory compliance and migration behavior. Judgments on “non-toxic / environmentally friendly” must be based on the regulations of the target market (such as REACH, RoHS, relevant GB food-contact standards, pharmacopoeias, etc.) and actual test results.

How to Quickly Build Your Own Plasticizer Selection Strategy?

Given the wide variety of plasticizers available, a simple “three-step approach” can help quickly narrow down the options:

1. Start from the application scenario:

(1) General-purpose / cold-resistant / high-temperature / flame-retardant / high-insulation / non-toxic / non-migrating / transparent, etc.

2. Then choose the structural category:

(1) General-purpose → high-carbon phthalates / terephthalates

(2) Cold-resistant → aliphatic dicarboxylates

(3) High-temperature + high-insulation → trimellitates + polyesters

(4) Non-toxic → citrates + epoxidized vegetable oils + specific polyesters

(5) Flame-retardant → phosphate esters + chlorinated plasticizers

(6) Non-migrating → polyesters + trimellitates

3. Finally, fine-tune according to formulation metrics:

(1) Use hardness, volume resistivity, Martin heat resistance temperature, low-temperature brittleness temperature, and volatility / migration data as feedback to fine-tune plasticizer types and dosage.

Aladdin: https://www.aladdinsci.com/