Esin Ozyazgan – A Glance at the Evolution of Antifreeze and Coolant Technology

Antifreeze, a crucial component of engine coolant, has a history dating back to 1916. Coolant, a mixture of antifreeze and water, helps regulate engine temperature. The first application of ethylene glycol antifreeze was proposed in the UK, and in 1927, the Prestone brand introduced it to the market. By the 1940s, as the importance of reducing engine wear became evident, ethylene glycol antifreeze gained widespread use. Over time, advancements in radiator and engine component materials spurred further development in antifreeze technology. This evolution has played a significant role in the automotive industry, enabling engines to operate more efficiently and safely.

Esin Özyazgan, the Technical Manager at ADCO, which is a trusted distributor in the lubricants sector and excels in meeting customers’ additive and antifreeze needs through long-standing global collaborations, shares historical insights into the development of coolants and discusses the advanced technologies used in this field.

Historical Development

Antifreeze is an additive that lowers the freezing point of water-based liquids, commonly used as a coolant in motor vehicles. When internal combustion engines first appeared in 1876, pure water was initially used for cooling. However, due to water’s limited freezing and boiling points, it proved insufficient for the efficient operation of engines.

In 1856, French chemist Charles-Adolphe Wurtz synthesized ethylene glycol, a substance with a lower freezing point and a higher boiling point than water. By 1926, ethylene glycol began to be used as automotive antifreeze and became widespread during World War II.

In the 1970s, antifreeze formulations contained nitrites, amines, and phosphates (NAP technology), but these ingredients posed environmental concerns. During the 1980s, Europe pioneered environmentally friendly alternatives by adopting NAP-free formulations. The 1990s saw the introduction of long-life organic antifreeze standards, particularly Organic Acid Technology (OAT), marking a significant step towards enhancing environmental sustainability and improving engine protection.

Today, organic compounds like ethylene glycol and propylene glycol are widely utilized. Ethylene glycol is favored for its superior heat transfer capacity, while propylene glycol is chosen in certain applications due to its lower toxicity. Additionally, modern antifreezes incorporate corrosion and cavitation inhibitors, which help extend the lifespan of engines and cooling systems.

Composition of Modern Antifreeze

The composition of modern antifreeze is carefully formulated to ensure efficient and safe engine operation. The basic ingredients include ethylene glycol (EG), the most commonly used base fluid, and propylene glycol (PG), which is preferred in some applications due to its lower toxicity. Additionally, silicates, phosphates, and organic acids are used as corrosion inhibitors, while pH buffers help maintain pH balance. Dyes are added for color and leak detection, and thickeners are included to achieve the desired consistency. This combination of ingredients allows modern antifreeze to ensure safe and efficient engine operation, even at extreme temperatures.

Corrosion inhibitors in coolants prevent corrosion risks in engines in two ways: in inorganic technologies, by forming an external film on metal surfaces, and in organic technologies, by promoting oxidation on metal surfaces. In inorganic types of antifreeze containing silicates, particularly in heavy-duty engines, gelation problems occurred due to silicates’ polymerization. Organic Acid Technology (OAT) was developed to address this issue, effectively solving the gelation problem.

At this point, let’s compare coolers for light-duty (LD) and heavy-duty (HD) vehicles:

There are significant differences between LD and HD engine coolers. Heavy-duty engines require more effective cooling systems due to their high performance requirements and harsh operating conditions. Coolants play a critical role in enhancing engine efficiency and extending engine life. LD coolants typically last up to 250,000 km, while HD coolants can last up to 1,200,000 km.

The advantages of Organic Acid Technology (OAT) are as follows:

• Long Life: OAT provides protection for 250,000-500,000 km, especially in heavy-duty applications.
• Environmentally Friendly: It has biodegradable properties.
• Heat Resistance: It withstands high temperatures and meets the engine’s cooling needs.
• Material Protection: It prevents wear and corrosion of aluminum and other metal surfaces.

OAT is used in many sectors, including agricultural machinery, construction machinery, and heavy-duty vehicles. This technology not only improves engine performance but also increases business efficiency by reducing maintenance costs.

Engine Downsizing

Traditional internal combustion diesel and gasoline engine manufacturers have begun downsizing their engines to create more efficient vehicles and lower emissions in response to legal requirements. By reducing engine capacity and the number of cylinders, and incorporating turbocharging and direct injection technologies, smaller engines can now perform as well as larger ones. This process has improved efficiency and reduced carbon emissions, while also increasing vehicle agility.

These advancements in engine technology have heightened the need for effective heat dissipation in coolants. Consequently, the use of coolants with high reserve alkalinity and heat resistance has become more important. In light of these developments, three key trends in antifreeze technologies have emerged:

1. Increasing Alkalinity Reserve Values: Over time, alkalinity reserve values have risen, enhancing the protective properties of antifreeze products.
2. Improved Heat Resistance: New formulations exhibit better resistance to high temperatures, boosting engine performance.
3. Silanization of Pure OAT Technology: Special organic acids are used to protect aluminum and light alloys.

Research ın the 1990s ındıcated that mıxıng OAT and ınorganıc antıfreeze ıncreased corrosıon rates, suggestıng that the mıscıbılıty of dıfferent types of antıfreeze should be lımıted. However, ın 2003, VW conducted extensıve fleet testıng, whıch demonstrated that laboratory results were not consıstent wıth actual servıce performance. The testıng proved that there was no problem wıth mıscıbılıty between OAT (ref. Spec.: TL 774D/F) and ınorganıc antıfreeze.

Specification Developments

The specifications for engine coolants have evolved significantly over time. ASTM D3306, published in 1974, established the first standards for light-duty and heavy-duty engine coolants. By 1989, separate specifications were needed for heavy-duty applications, leading to the creation of ASTM D4985 and ASTM D5752, which set standards for low-silicate ethylene glycol-based coolants for heavy-duty engines.

These specifications have been updated to reflect changes in engine material composition and environmental impacts, with increased emphasis on protecting aluminum and light alloys.

Organic acid technology enhances environmental sustainability and improves the cost-effectiveness of industrial applications. In the future, further optimization of these technologies will play a significant role in reducing the automotive industry’s environmental impact.

The color of antIfreeze ındıcates ıts composıtıon and helps consumers select the approprıate product. However, dıfferent manufacturers use varıous color codes, makıng ıt challengıng for users to choose the correct antıfreeze. Therefore, standardızıng antıfreeze colors ıs crucıal.

As ADCO, the leading distributor in the lubricants and chemicals sector in the Turkish market since 1977, we closely follow the evolving antifreeze technology with the Italian company Tecnofluid, which we represent.

With our ever-expanding product portfolio, Tecnofluid, renowned for its deep-rooted history and expertise in antifreeze and coolants, offers high-quality products designed to meet your needs.