POLYMER MODIFIED BITUMEN (PMB)

WHAT IS POLYMER MODIFIED BITUMEN (PMB)?

Polymer Modified Bitumen (PMB) has polymer additions to improve its characteristics. Bitumen, a thick, black, sticky substance produced from crude oil distillation, is used to bond roads.

The addition of polymers to bitumen modifies its physical and chemical characteristics, making it more robust, resilient, and resistant to temperature fluctuations, rutting, cracking, and aging. PMB is utilized in road building, roofing, waterproofing, and other civil engineering applications.

Styrene-butadiene-styrene (SBS), styrene-butadiene rubber (SBR), ethylene-vinyl acetate (EVA), and polyethylene may change bitumen (PE). Polymer choice relies on PMB characteristics and application.

Polymers increase performance and endurance to bitumen, making it a desirable building material.

Petro Naft manufactures the highest quality Polymer Modified Bitumen PMB in different types and grades and exports them from Iran and the UAE to other countries around the world.

• Iran Polymer Modified Bitumen ( Iran PMB )
• UAE Polymer Modified Bitumen ( UAE PMB )

POLYMER MODIFIED BITUMEN (PMB) HISTORY

Delving into the intriguing journey of Polymer Modified Bitumen, or PMB, we must rewind the clock back to the early 20th century. This was when asphalt material science started making leaps in understanding and practicality. However, the birth of PMB, as we recognize it today, wasn’t until the 1930s when German inventors utilized polymers to enhance the properties of bitumen.

PMB’s existence traces back to the desire to improve bitumen’s durability and resilience, particularly for road construction. This new variant of bitumen, also known as modified bitumen or elastomer modified bitumen, provided a significant increase in performance. It extended the lifespan of roads, reducing maintenance frequency, and proved vital in withstanding diverse climatic conditions.

Progress in the field of PMB was slow yet steady during the mid-20th century. It wasn’t until the 1970s that PMB’s use took a real upswing, especially in Europe. This advancement was due to the commercial production of Styrene-Butadiene-Styrene (SBS) polymers, a critical component in PMB production. The new material provided enhanced elasticity, improved resistance to deformation, and heightened temperature stability.

In the early 2000s, with the development of the Functional Polymer Modified Bitumen (FunPMB), PMB started stepping into an era of sustainable and functional road building. The Functional PMB proved advantageous for their environmental benefits, including reduced emissions during production and installation, and noise reduction for the end-user.

Today, PMB is considered an essential tool in the construction industry, promising sustainability, durability, and superior performance. The journey of PMB reflects our constant pursuit for improvement and innovation, signifying the role of materials science in shaping our infrastructural future.

As we continue to traverse this road, we are equipped with the power of history and the promise of science, driving the evolution of products like PMB. Here’s to paving the way forward with Polymer Modified Bitumen, transforming landscapes and setting new standards in infrastructure development.

POLYMER MODIFIED BITUMEN OTHER NAMES

Polymer Modified Bitumen, a vital material in construction, particularly in paving and roofing applications, is known by several other names, including:

1. Modified Bitumen
2. Modified Asphalt
3. Elastomer Modified Bitumen
4. Plastomer Modified Bitumen
5. PMB
6. Bitumen Modifier (when the focus is on the additive)
7. Thermoplastic Bitumen
8. Rubberized Bitumen (particularly when using certain types of polymers)
9. SBS Modified Bitumen (when Styrene-Butadiene-Styrene is the polymer used)
10. APP Modified Bitumen (when Atactic Polypropylene is the polymer used)

These names all refer to Bitumen that has been altered by the addition of polymers to enhance its physical properties, including durability, flexibility, and resistance to environmental elements. The specific name used often depends on the type of polymer added or the application the modified bitumen is intended for.

POLYMER MODIFIED BITUMEN (PMB) HS CODE, CHEMICAL FORMULA AND CAS NUMBER

The Harmonized System (HS) Code for Polymer Modified Bitumen falls under the category of 2715, specifically 27150000, which comprises bituminous mixtures based on natural asphalt, natural bitumen, petroleum bitumen, mineral tar or mineral tar pitch.

As for its chemical composition, PMB doesn’t have a specific chemical formula due to its complex, varied structure depending on the type of polymer used. However, the chemical formula for bitumen, which is the base material for PMB, is roughly C25H32. The specific structure and formula will change with the addition of polymers.

Likewise, due to the varied nature of the PMB depending on the specific polymer modification, there isn’t a single Chemical Abstracts Service (CAS) number applicable. The CAS number for Bitumen is 8052-42-4. Polymers used, such as APP or SBS, have their own CAS numbers: 9003-07-0 and 9003-55-8 respectively.

POLYMER MODIFIED BITUMEN (PMB) COMPONENTS AND MATERIALS

Polymer Modified Bitumen (PMB) is a composite material that consists of the following primary components:

1. Bitumen: Bitumen, also known as asphalt, is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It forms the base of PMB and is the component that provides the initial adhesive and waterproofing characteristics.

2. Polymers: Polymers are added to the bitumen to improve its physical properties. There are primarily two types of polymers used:

   • Elastomeric Polymers: These polymers, including Styrene-Butadiene-Styrene (SBS) and Styrene-Butadiene Rubber (SBR), enhance the elastic properties of the bitumen, increasing its flexibility and resilience at both high and low temperatures.

   • Plastomeric Polymers: These polymers, such as Atactic Polypropylene (APP) and Ethylene Vinyl Acetate (EVA), provide increased rigidity and resistance to aging.

3. Fillers: Materials like limestone, fly ash, or carbon black may be used as fillers to improve the stiffness and reduce the cost of the PMB.

4. Additives: Various additives may be incorporated to further enhance the properties of the PMB. These can include antioxidants for improved resistance to aging, adhesion promoters for better bonding with the aggregate in road construction, and fire retardants for increased fire resistance in roofing applications.

5. Stabilizers: To ensure the polymer doesn’t separate from the bitumen during storage or transport, stabilizers are added.

The specific composition of PMB can vary greatly depending on the intended application, the performance requirements, and the specific manufacturing process used. However, the goal is always to create a product that combines the adhesive and waterproofing properties of bitumen with the enhanced durability, flexibility, and resistance to environmental stresses provided by the polymers.

POLYMER MODIFIED BITUMEN (PMB) GRADES MOST COMMONLY USED

1. PMB 120:

Characteristics:

• Penetration at 25°C: This grade has a relatively high penetration range of 90-150 (1/10mm under 100g for 5 seconds).
• Softening Point: PMB 120 has a minimum softening point of 50°C.

Usage and Applications: Given its higher penetration, PMB 120 is likely to be more ductile and flexible, making it suitable for regions with colder climates or applications that require more pliability.

2. PMB 70:

Characteristics:

• Penetration at 25°C: PMB 70 has a mid-range penetration value between 50-90.
• Softening Point: Its softening point is a bit higher than PMB 120, with a minimum of 55°C.

Usage and Applications: PMB 70 can be considered an intermediate grade in terms of its rigidity and ductility. It could be ideal for temperate regions or applications that require a balance between flexibility and stability.

3. PMB 40:

Characteristics:

• Penetration at 25°C: This grade has the lowest penetration range of 30-50, indicating it’s the least ductile among the three.
• Softening Point: PMB 40 possesses the highest minimum softening point of 60°C among the three grades.

Usage and Applications: With its lower penetration and higher softening point, PMB 40 is likely to be the most rigid and stable of the three. It’s suitable for hotter climates or applications where resistance to softening and rutting is crucial.

BEST WAY TO CLASSIFY POLYMERS IS BY THEIR APPLICATION AND TEMPERATURE BEHAVIOR

There are many different ways to classify polymers, including whether they are natural or synthetic, the type of arrangement of monomers, the arrangement of chains, and the method of polymerization. However, from the perspective of the scientific community, the classification of polymers that is most useful is based on how they behave in terms of their applications and temperatures, and this classification is broken down into three subgroups:

• Thermoplastic
• Thermoset
• Elastomer

Thermoplastics:

These types of polymers are softened by heat and melted by heat and can take the shape of the mold, and by removing the cooled heat, they turn into a solid state, and this cycle can be repeated several times without changing the properties of the polymer. be repeated Polypropylene (PP), polyethylene (PE) and polystyrene (PS) are part of this category.

Thermosets:

These are semi-solid polymers that harden due to the application of heat and are no longer soft and meltable, and are destroyed and lose their properties when heated continuously. In fact, if we examine the intermolecular force of these two groups of polymers, thermoplastics have a weak intermolecular force that can change the shape of the polymer by heating, but thermoset polymers have strong crosslinks that allow shaping and reprocessing. They do not exist. Polyester, polyurethane, resins and silicones are examples of this group.

Elastomers:

The name elastomer is derived from the combination of two words, elastic polymer. Elastic means to be elastic, which means that when a force or stress is applied to elastomers, they first change their shape, and when the stress is removed, they rearrange their chains and return to their original state. One of the main features of these materials is having a very low glass transition temperature. That is, these materials are soft at low temperatures. (It should be noted that polymers are very hard and brittle below their glass transition temperature). All kinds of rubbers, including butadiene rubber, natural rubber, are members of this group.

Thermoplastic elastomers are another kind of polymer:

In addition to thermoplastic polymers and elastomer polymers, there is also a category of polymers known as thermoplastic elastomers. These thermoplastic elastomers are created by combining two different types of polymers. This is due to the fact that the beneficial characteristics of both groups are combined, resulting in the formation of a copolymer that is capable of making use of the primary and functional characteristics of both groups. For instance, elastomers are unable to melt and would be destroyed if heat is repeatedly applied, but thermoplastics have both the capacity to melt and the property of being plastic. Polyurethane, polyether-polyester copolymer, olefinic copolymer, and styrene block copolymers are the four primary categories of thermoplastic elastomers. Polyurethane is the most common kind. The findings of the final group have shown to be the most successful when combined with bitumen. In a nutshell, the thermoplastic nature of TPE polymers, in addition to their low viscosity at high temperature and their capacity to open up in bitumen, as well as many other important characteristics, have led to this polymer being recognized as the most effective modifier of the properties of bitumen. For instance, the styrene component of SBS polymer, which is a styrene-butadiene-styrene block copolymer and is an elastomer thermoplastic, is of the thermoplastic kind, while the butadiene component is of the elastomer variety.

The temperature at which butadiene rubber (PB) undergoes its glass transition is -70 degrees Celsius, but the temperature at which polystyrene undergoes its glass transition or softening temperature is 100 degrees Celsius. The thermal stability of this material is improved by combining these two polymers, which allows for a wider temperature range at which it can maintain its integrity. The usefulness of using SBS polymer to generate modified polymer bitumen has been shown, making it one of the best polymers, if not the greatest polymer, employed in the industry that produces bitumen and asphalt. Because a portion of it is composed of rubbers, which, thanks to their very low glass transition temperature, increase the performance of bitumen when exposed to low temperatures and throughout the winter.

Other polymers used:

One of the polymers that has garnered attention in the bitumen and asphalt sector nowadays is polyphosphoric acid. Another one of these polymers is polyethylene glycol. The combination of polyphosphoric acid and bitumen has been the subject of a significant amount of penetration, and the findings have revealed that even a minute quantity of this polymer can boost the softening point of bitumen by ten degrees and reduce the degree to which it can be penetrated by five degrees. Additionally, polyphosphoric acid may be used as a bitumen compatibilizer when combined with other polymers such as rubber powder; however, it is essential to keep in mind that a high-speed mixer is required for this process.

POLYMER MODIFIED BITUMEN (PMB) ADVANTAGES AND BENEFITS

Because the temperature at which bitumen breaks is approximately -10 to -12 degrees, the use of bitumen in areas where the temperature drops below -12 degrees during the winter will cause the bitumen to break and create cracks on the asphalt surface. This is due to the fact that bitumen is both hard and fragile. Because of the usage of rubbers, the temperature at which asphalt will break may be lowered to as low as -30 degrees or even lower. This lowers the temperature at which cracks and other types of asphalt damage can occur during the winter. On the other hand, the addition of this polymer to bitumen causes a rise in the viscosity of the bitumen and a rise in the temperature at which it begins to soften at high temperatures and hot conditions. This helps to prevent the bitumen from becoming loose and rutting in asphalt. In point of fact, one of the reasons why bitumen and asphalt are modified with polymers is in order to make the roadway surface more durable in a variety of climates.

Normal bitumens develop fatigue cracks in a very short amount of time on roads that have a high traffic load; however, the usage of polymer-modified bitumen and asphalt enables us to have longer periods of time. For there to be no cracks in the asphalt and for the coating to be in good condition. Because of this, it is not necessary to apply protective asphalts while stamping and sealing the asphalt surface, which results in savings in both money and energy. When thermoplastics like polyethylene or polypropylene, which are examples of thermoplastics, are added to bitumen, the characteristics of the bitumen are improved, and the result is a higher softening point and a lower degree of penetration. Additionally, this component raises the high temperature at which PG or performance grade bitumen can be used, which results in improved performance of bitumen in tropical regions. However, the findings of the study and the experiments have shown that the use of polyethylene leads in the bitumen being more brittle at lower temperatures. It is important to keep in mind that the use of polyethylene polymer in colder places not only does not result in an improvement in the qualities of bitumen, but it actually degrades the substance.

In general, depending on the kind of polymer, bitumen may take on a variety of characteristics, and here are a few of those characteristics that we will mention:

1- Raising the bitumen’s soft point, which prevents asphalt from being rutted during the summer and when temperatures are high.

2- Lessening the degree to which the bitumen penetrates the asphalt, which stops moisture from getting into the asphalt infrastructure when it rains.

3- Raising the elasticity or reversibility of bitumen, which raises the bitumen’s resistance against permanent deformations and, more crucially, lowers the number of fractures produced by the cold during the winter season.

POLYMER MODIFIED BITUMEN (PMB) PRODUCTION PROCESS

In a stirred tank, a bitumen component is heated to a temperature between 185° C. and 221° C. and a block copolymer composition is added while the bitumen component is being stirred to form a homogeneous mixture. This method produces a PMB polymer modified bitumen binder composition in the substantial absence of cross-linking agents. A cured polymer modified bitumen binder composition is created by mixing the block copolymer composition with the homogeneous mixture and keeping the temperature between 185° C and 221° C for a length of time between 4 hours and 30 hours. Different types of polymers are utilized in this procedure, and they are selected based on a certain formula.

 POLYMERS MODIFIED BITUMEN (PMB) TYPES

POLYMER MODIFIED BITUMEN (PMB) SPECIFICATIONS

Polymer Modified Bitumen (PMB) specifications can vary depending on the intended use, such as roofing or paving, and the specific type of polymer used. However, there are some general characteristics and properties that are often specified:

1. Penetration: This is a measure of the hardness or softness of the bitumen, assessed by the depth a standard needle penetrates into a bitumen sample under specific conditions. PMB typically has a lower penetration value than unmodified bitumen, indicating a harder material.

2. Softening Point: The softening point is the temperature at which the bitumen becomes soft and less viscous. PMB generally has a higher softening point than unmodified bitumen, which means it can withstand higher temperatures before softening.

3. Elastic Recovery: This measures the bitumen’s ability to recover its original shape after being stretched or deformed. For PMB, the elastic recovery should be high, often above 70%, indicating a high level of flexibility and resilience.

4. Fatigue Resistance: PMB should exhibit excellent resistance to fatigue, meaning it can withstand repeated cycles of stress without failure.

5. Rutting Resistance: PMB is expected to have a high resistance to rutting, which is deformation or grooving that occurs over time, particularly in high-temperature conditions or under heavy loads.

6. Resistance to Aging: PMB should have a high resistance to aging, which means it can withstand exposure to the elements, including UV light and varying temperatures, without significant degradation over time.

7. Compatibility: PMB should be compatible with the aggregates used in road construction or the materials used in roofing applications.

8. Polymer Content: The amount and type of polymer used in the PMB must be specified. Common types include SBS (Styrene-Butadiene-Styrene) and APP (Atactic Polypropylene), and the polymer content is usually between 3-7%.

It’s important to note that specifications can vary by region and application, and different standards may apply. Examples of organizations that provide specifications for PMB include the American Association of State Highway and Transportation Officials (AASHTO), the Asphalt Institute, and the European Committee for Standardization (CEN). Always refer to local and application-specific guidelines when working with PMB.

POLYMER MODIFIED BITUMEN (PMB) PROPERTIES

Polymer Modified Bitumen (PMB) boasts several distinctive properties that set it apart from traditional bitumen. The addition of polymers enhances the bitumen’s original qualities and introduces new characteristics, making it suitable for a variety of applications.

1. Enhanced Elasticity: PMB is more elastic than traditional bitumen, thanks to the inclusion of elastomeric polymers. This increased elasticity allows PMB to regain its original shape after being deformed, enhancing its resistance to rutting and fatigue cracking.

2. Improved Durability: PMB exhibits superior durability. The polymers help protect the bitumen from the effects of aging, oxidation, and UV radiation, leading to a longer lifespan and improved performance over time.

3. Greater Resistance to Temperature Extremes: PMB can withstand a broader range of temperatures without losing its structural integrity. It retains its flexibility in cold temperatures, reducing the risk of thermal cracking, and it is more resistant to softening and rutting in hot conditions.

4. Increased Adhesion: PMB’s adhesive properties are improved, ensuring better bonding with aggregate materials in road construction or with roofing materials, contributing to the overall durability of the finished structure.

5. Enhanced Resistance to Water Damage: PMB is more resistant to water damage than traditional bitumen. This quality makes it excellent for waterproofing applications and in environments where water damage could be a concern, such as roadways.

6. High Skid Resistance: PMB has high skid resistance, making it a safe option for high-traffic roadways and other areas where skid resistance is important for safety.

7. Superior Fatigue Resistance: PMB can handle repeated cycles of stress without failure, a crucial feature in applications like road construction where the material experiences constant loading and unloading from traffic.

These properties make PMB a preferred choice for applications demanding high-performance, longevity, and durability, such as road construction, roofing systems, and waterproofing projects.