Two Essential Blowing Agents: Cyclopentane and Pentane

In the world of insulation and polymer manufacturing, blowing agents play a critical role in creating lightweight, energy-efficient materials. Among the most widely used are cyclopentane and pentane, both hydrocarbon compounds known for their effectiveness and environmental advantages. Let’s explore their properties and applications.

Cyclopentane: Properties and Applications

Physical and Chemical Characteristics

Cyclopentane is a colorless, highly volatile liquid with a distinct gasoline-like odor. Key properties include:

• Freezing Point: –94°C
• Boiling Point: ~49°C
• Vapor Density: 2.4 times that of air
• Vapor Pressure: 36.6 kPa at 20°C; 69 kPa at 38°C
• Density (20°C): 0.745 g/cm³
• Flash Point (closed cup): –37°C (Highly flammable)
• Autoignition Temperature: 361°C
• Explosion Limits (vol%): 1.5% – 8.7%
• Occupational Exposure Limit (TLV/TWA): 600 ppm

Technical Specifications

Commercial-grade cyclopentane typically meets the following standards:

• Appearance: Clear, colorless liquid with no suspended solids
• Purity: ≥99%
• Moisture Content: <50 ppm
• Non-volatile Residue: <10 ppm
• Acidity: Neutral, free of acidic substances

Application Highlights

Cyclopentane is prized for its zero ozone depletion potential (ODP) and zero global warming potential (GWP), making it an ideal replacement for CFC-11 in foam production. It is commonly used in:

1. CFC-free refrigerators and freezers
2. Cold storage insulation systems
3. Pipeline thermal insulation

Usage Notes

• Cyclopentane has limited solubility in polyether polyols, so low-viscosity polyols are preferred.
• It can be blended with isopentane to optimize performance.

Pentane: Properties and Applications

Pentane refers to a group of isomers, primarily n-pentane and isopentane, both used in industrial applications.

Physical and Chemical Characteristics

At room temperature, pentane is a clear, colorless liquid with a faint aromatic odor. It is:

• Free of olefins
• Free of suspended solids and water

Technical Specifications

Typical industrial-grade pentane meets the following criteria:

• Appearance: Clear, no sediment or haze
• Purity: ≥99% for n-pentane; ≥98% for isopentane
• Composition: n-pentane is rich in straight-chain alkanes; isopentane contains branched isomers
• Moisture Content: <20 ppm
• Sulfur Content: <1 ppm
• Bromine Index: Low (indicates minimal unsaturated hydrocarbons)

Application Highlights

Pentane is derived from efficient distillation of light hydrocarbons from oil fields. Its main uses include:

1. Desorption agent in molecular sieve dewaxing (n-pentane)
2. Blowing agent for expandable polystyrene (EPS) — often a blend of n- and isopentane
3. Polyurethane foam production, often in combination with cyclopentane

Environmental and Industrial Relevance

Both cyclopentane and pentane are vital in the shift toward eco-friendly insulation materials. Their low environmental impact and high efficiency make them indispensable in modern manufacturing, especially as industries move away from ozone-depleting substances.

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Choosing between n-Pentane, Isopentane and Cyclopenane depends on the intended use. Here are some general differences between them:

• Pentane is a colorless, volatile liquid, mainly used for chemical experiments, solvent and solvent mixture preparation, and also an important raw material in the petroleum industry.
• When buying pentane, you should pay attention to the following aspects:
  • Purity: The higher the purity of pentane, the better its performance and quality, but the higher the price. According to different uses, you can choose different purity grades, such as AR, CP, GCS, GR, HPLC, agricultural residue grade, etc.
  • Packaging: Pentane is a flammable liquid and should be packed and stored in suitable sealed containers to prevent leakage and fire. Generally speaking, the packaging specifications of pentane are 200L steel drums and ISO tank containers.
  • Price: The price of pentane is affected by many factors such as market supply and demand, raw material cost, transportation cost, etc., generally ranging from hundreds of USD to thousands of USD. When buying, you should compare the quotations of different manufacturers and channels, and choose products with high cost performance.
  • Manufacturer: There are many manufacturers of pentane, and there are great differences in production scale, technology level, product quality, etc. You should fully understand the qualifications, reputation, after-sales service, etc. of the manufacturers when buying. You can choose regular, professional and reliable manufacturers through the Internet, industry associations, peer recommendations, etc.

Many manufacturers will be using a new, more environmentally friendly insulation material, called cyclopentane, in the manufacture of select refrigerators and freezers. Cyclopentane is a blowing agent for the polyurethane foams that are used to insulate refrigerators and freezers. Unlike some other chemicals used to insulate refrigerators, cyclopentane does not contain hydro-fluorocarbons (HFCs). Using cyclopentane results in significant reductions in equivalent CO₂ emissions. The most common foam-blowing agents currently used in the U.S. are R134a and R245fa. These industry-standard insulations can have a global warming potential (GWP) as high as 1300 (134a) and 950 (245a). In contrast, the foam-blowing agent cyclopentane has a GWP of approximately 10. When it comes to GWPs, the lower the number is, the better it is for the environment, so cyclopentane is clearly the more environmentally friendly choice. Cyclopentane increases the efficiency of the insulation foam by approximately 4 percent over the R134a foam currently used in most refrigeration products. Cyclopentane has been very popular as a blowing agent in Europe since the early 1990s, but the cost of retrofitting existing production facilities and the lack of U.S. regulations restricting the use of HFCs has delayed implementation in the U.S. However, there are other manufacturers currently selling refrigerators in the U.S. that use cyclopentane. Compared to other insulating foams, cyclopentane is competitively priced and relatively easy to produce. Like many gases, in its pure form, cyclopentane is a highly evaporative and flammable material. However once foamed, the unit is no more hazardous than a unit foamed with other blowing agents. As with any of our manufacturing processes, we’ve integrated a wide variety of redundant engineering and operational safeguards. To learn more about cyclopentane, click here.

 Common questions about cyclopentane

Q: What is this new material being used in the foam insulation?
A: The new material is called cyclopentane, a highly evaporative gas that is used to apply the foam insulations in refrigeration units. 

Q: What is cyclopentane?
A: Cyclopentane is a blowing agent for the polyurethane foams that are used to insulate refrigerators and freezers. 

Q: What are the benefits of using cyclopentane instead of other materials?
A: From an environmental perspective, unlike some other chemicals used to insulate refrigerators, cyclopentane does not contain hydro-fluorocarbons (HFCs). Using cyclopentane results in significant reductions in equivalent CO₂ emissions. 

Q: What foam-blowing agents are most commonly used in the U.S.? How is cyclopentane different?
A: The most common foam-blowing agents in the U.S. right now are R134a and R245fa. These two industry-standard insulations can have a global warming potential (GWP) as high as 1300 (134a) and 950 (245a). Comparatively, the foam-blowing agent cyclopentane has a GWP of approximately 10. When it comes to GWPs, the lower the number is, the less adverse impact on the environment, so cyclopentane is clearly a better choice. 

Q: Are there significant insulating advantages, as well?
A: Yes, cyclopentane is approximately 4 percent more efficient than the R134a foam we currently use in most of our products. 

Q: Do other refrigerators available in the U.S. market use cyclopentane?
A: There are other manufacturers currently selling refrigerators in the U.S. that use cyclopentane. 

Q: Why hasn’t cyclopentane caught on in the United States?
A: It has been very popular as a blowing agent in Europe since the early 1990s, but the cost of retrofitting existing production facilities and the lack of U.S. regulations restricting the use of HFC’s has delayed implementation in the U.S. 

Q: Is it more expensive than other insulating materials?
A: It is competitively priced and relatively easy to produce. 

Q: Is it dangerous?
A: Like many gases, in its pure form, cyclopentane is a highly evaporative and flammable material. However once foamed, the unit is no more hazardous than a unit foamed with other blowing agents. As with any of our manufacturing processes, we’ve integrated a wide variety of redundant engineering and operational safeguards.

The difference between EPS fire resistance grades A, B, and B1:

1. Fire resistance coefficient: Class A is non combustible; Level B is further divided into three levels, with B1, B2, and B3 having different levels of combustion.
2. Flammability: Class A has zero flammability;, B1 is flame retardant, B2 is flammable, and B3 is flammable.
   At present, the common A-grade products in the market include phenolic aldehyde, rock wool, insulation mortar, foam ceramics, foam glass, and foam concrete. At present, the most advantageous A-grade material is foamed concrete, also known as foamed cement.
   EPS polystyrene board itself is a flammable material, so it is not a fireproof material in terms of fire rating. So it’s not at all A-level or B1 level. The fire resistance rating of polystyrene boards on the market is only B2 (flammable) and B3 (flammable).
   Extended Information:
   EPS physical and mechanical properties:
3. Density
   The density of EPS is determined by the expansion ratio of polystyrene particles during the forming stage, which is generally between 10 and 45kg/m3. As EPS used in engineering, its apparent density is generally between 15 and 30kg/m3.
   At present, the density of EPS used as lightweight filling material in road engineering is 20kg/m3, which is 1% to 2% of that of ordinary road filling material. Density is an important indicator of EPS, and its mechanical properties are almost directly proportional to its density.
4. Deformation characteristics
   When the confining pressure exceeds 60KPa, the yield strength significantly decreases, which is clearly different from the variation law of the soil. When axial strain ε When a ≤ 5%, regardless of the confining pressure, the volumetric strain ε V is close to axial strain ε a. The lateral deformation of EPS is small, which means the Poisson’s ratio is small.
   To minimize post construction settlement, after laying the EPS material layer, fill 1.2m of soil on it for preloading. The average compressive settlement of the EPS material layer is 32mm, and it can be calculated that the elastic modulus of EPS is 2.4MPa, and the EPS material is still in the elastic deformation stage.
5. Self-reliance
   The self-sustaining nature of EPS is very beneficial for the stability of high slopes. Due to the small lateral pressure generated by the vertical compression of EPS, the use of EPS as filling material for the roadbed at the bridge head can greatly reduce the soil pressure behind the abutment, which is very beneficial for the stability of the abutment.
   The friction coefficient f between EPS block and sand is 0.58 (dense)~0.46 (loose) for dry sand and 0.52 (dense)~0.25 (loose) for wet sand; The range of f between EPS blocks is between 0.6 and 0.7.
6. Water and temperature characteristics
   The closed cavity structure of EPS determines its good insulation performance. Its biggest characteristic when used as insulation material is its extremely low thermal conductivity, with various specifications of EPS boards having thermal conductivity ranging from 0.024W/m.K to 0.041W/m.K. EPS is a thermoplastic resin that should be used below 70 ℃ to avoid thermal deformation and strength reduction.
   Simultaneously utilizing this feature, electric heating wire processing can be used. Flame retardants can be added in production to form flame retardant EPS. Flame retardant EPS extinguishes itself within 3 seconds after leaving the ignition source. Due to the much lower bulk density of EPS compared to soil, the 1% to 10% increase in bulk density caused by water absorption can have negligible impact on engineering.
7. Durability
   EPS has stable chemical properties in water and soil, and cannot be decomposed by microorganisms; The cavity structure of EPS also makes water infiltration extremely slow; If exposed to ultraviolet radiation for a long time, the surface of EPS will change from white to yellow, and the material will appear brittle to some extent; EPS has stable properties in most solvents, but can be dissolved in organic solvents such as gasoline, diesel, kerosene, toluene, acetone, etc. This indicates that EPS fillers require a good protective layer.
   
   Reference Source: JUNYUAN PETROLEUM GROUP – EPS Blowing Agent Department (Folystyrene Foam)

Expandable polystyrene (EPS)

Revolutionary patented polystyrene production method

Expandable polystyrene (EPS) consists of polystyrene micro-pellets or beads containing a blowing agent and other additives for foaming. We have developed a continuous production process in which the blowing agent is directly injected into the melt, combined with subsequent underwater pelletization.

Commercial EPS is manufactured with the addition of a blowing agent, typically a chlorinated hydrocarbon or a low-boiling petroleum-derived agent with the presence of pentane. These substances are highly flammable; by reducing the amount of flame retardant due to the addition of gypsum, they ignited during the flame propagation test, increasing the burn rate of the GPS.

Main benefits

• The patented EPS process is economical, compact, and easy to operate
• Continuous process for consistent product quality
• Dispersing a wide range of additives and pigments is possible
• Minimized waste production
• Reduction of wastewater and process water
• Recycling possibility for waste EPS pellets/beads/foam
• Process allows developing innovative applications

Main applications

• Expandable Polystyrene

EPS Panel

The self-extinguishing, fire-retardant EPS Panel foam is manufactured from 100% virgin bead and oven-cured after manufacture to ensure the resulting blocks are completely dry and free from all residual pentane.

EPS Panel is a lightweight, CFC-free, non-brittle, closed cell insulator with more consistent thermal performance over time. It has a high dimensional stability and low water vapor transmission.

A special chemical coated to the Expanded Polystyrene beads (raw material) distinguished it from standard/common EPS Panel. Fire-Retardant EPS Panel is a self-extinguishing, non-combustible material.

Fire-retardant EPS Panel with a density of 15 kg/m3 is used for clean rooms, food processing facilities and modular buildings, while the 20 kg/m3 is used for industrial and commercial cold storage.

Core

Width (cover mm)
Thickness (mm)
Length
Exterior Facing Skin
Internal Facing Skin
Standard Colors
Joint System
Finishes
Type of SkinEPS
(Expanded Polystyrene)
1,160
50, 75, 100, 125, 150, 200, 250
Up to 12 meters
0.5mm, 0.6mm G300 CRP Steel
0.5mm, 0.6mm G300 CRP Steel
Off White
Slip Joint
Plain, Ribbed, Diamond
Anti Bacterial (AB)
Food Grade (FG)
Xterior Roof and Wall (XRW)

Features and Advantages

• Fire retardant
• Meets safety requirements
• Energy saving
• Longer lifetime
• Resistant to termites and rodents
• Customized design
• Easy to install saving cost of installation time
• High performance on insulated panel