Mastering the technology of fireproof paint using modification additives of the Institute of Materials Science

Helps steel structure withstand fire up to 120 minutes 

Iron and steel are like the backbone supporting a building. When a fire breaks out, the temperature rises so rapidly that it destabilizes the steel structure leading to collapse. With public buildings, ensuring the occupants have enough time to escape in the event of a fire is essential. Therefore, choosing a high-quality fireproof paint is extremely important and shows its use when a fire occurs.

In fireproof paint systems, the heating of steel structures is slowed down. Fireproof paint forms a thermal insulation on the steel surface by foaming in the presence of high temperatures. Foam insulation helps steel structures remain stable for 30-120 minutes, depending on the paint system. In terms of construction, steel materials can withstand an average heat of 350 - 750oC depending on the load.  Therefore, the choice of the best fire retardant paint system should be based on the load of the structures. The more floors and large loads a building has, the more stable fire retardant paint is needed. 

Dr. Nguyen Viet Dung, Director of Research Department of Polymer and Composite Materials, Institute of Materials Science, said that fireproof paint to protect steel structures has been the research topic of scientists since 2013. At that time, fireproof paint was just beginning to appear on the Vietnamese market. At this time, studies are focused on evaluating the applicability of minerals available in water such as sericite minerals, talc minerals in flame retardant paints based on epoxy resins. With high protective properties and especially high thermal resistance, sericite and talcum mineral powder products have had outstanding results, demonstrating their application potential in flame retardant paints.

Starting from 2018, the Research Department of Polymer and Composite Materials has perfected the formula of fireproof paint products containing modified additives as well as consulted and transferred modified additive products to domestic flame retardant paint manufacturers. Fireproof paint products with the combination of research laboratories right after its inception have shown the difference to existing products on the market, both in terms of properties and prices, helping businesses create a reputation in the field of fireproof paint production.

By the beginning of 2021, when the management agency changes the requirements for testing fireproof paint products (Decree 136) in the direction of improving quality and close to actual requirements, the Research Department of Polymer and Composite Materials immediately embarked on the process of researching and testing new fireproof paint product systems according to ISO 834-10:2014 and BS EN 13381-8:2013. Studies have focused more on the role of talc, as previous studies have shown that, in the presence of talc, the swelling coal layer forms voids inside the inflated structure that increase thermal insulation.

Figure 1: Photo of the swelling paint layer containing talcum mineral and the coalized layer pore structure

In addition, the Polymer and Composite Materials Research Department also experiments with the role of different adhesives, focusing on the molecular weight of polymers in order to find the optimal adhesive for the adhesion process of the bulge layer to steel structures (Nguyen Viet Dung et al, "The effect of binder molecular weight and talc mineral filler on expansion ratio and hardness in intumescent material" Vietnam J. Chem., 2022, 60 (special issue), 148-153). After completing the research, the Research Department of Polymer and Composite Materials has cooperated with enterprises to test products on structural samples in accordance with current standards and conduct tests at the Institute of Structural Construction, Institute of Construction Science and Technology (IBST).

Figure 2: The process of constructing test samples at Tui Liet technology deployment area (left image) and sample testing at IBST (right image)

Finishing fireproof paint products to meet new requirements

The sample testing process carried out at IBST according to ISO 834-10:2014 took place successfully in early 2022. Based on this successful test, the partner enterprise of Institute of Material Science has started the process of official registration and inspection of steel structure protection fireproof paint products with the Police Department of Fire Prevention, Fire Fighting and Rescue, meeting the requirements of the current Decree 136. After nearly 1 year of testing as well as completing legal procedures, by March 31, 2023, flame retardant paint products using modified additives provided by the Institute of Material Science have officially been granted an inspection certificate 1363/KD-Fire-P7 by the Police Department of Fire Prevention, Fire Fighting and Rescue. 

Figure 3: Photo of the inspection process and fire resistance paint inspection paper according to Decree 136

The successful development of a new system of additives for fire retardant paint has helped the fireproof paint enterprise partner of Institute of Material Science to be granted accreditation certificates for products by authorities, through which thousands of domestic construction projects and steel structure factories are eligible for fire prevention and acceptance to come into operation. The results of research cooperation between Institute of Materials Science and domestic fireproof paint manufacturers to meet the new requirements and regulations were highly appreciated by the Association of Fire Protection and Rescue in the meeting with Vietnam Academy of Science and Technology.

Modified additives for fireproof paints are developed steadily and continuously, bringing great revenue to Institute of Materials Science, Vietnam Academy of Science and Technology. In 2023 alone, the contract amount of fireproof paint products of Institute of Materials Science has reached over VND 17 billion. This figure also confirms the role of scientists and the potential of applied research in developing products with high scientific content, bringing valuable products to businesses, people and society.

Mastering the technology of solar thermal reflective paint using domestically produced nanomaterials of Institute of Tropical Technology

Weather resistance higher than 1500 hours 

Vietnam is entirely in the tropics. The average annual total radiation is high (about 120 kcal/cm2/year). Very hot weather in summer (direct radiation intensity can reach a maximum of 0.6 kcal/cm2/day in June and 8 in the North and months 4-5, 8-9 in the South) causes a great negative impact, causing a hot heat island effect in big cities such as Hanoi, Ho Chi Minh City, .... consuming a lot of energy due to cooling damage, making the power shortage even more serious, the petroleum industry is greatly damaged by the loss due to evaporation.

Recognizing the urgency and seriousness of the problem, since the 1990s, the research team at Institute of Tropical Technology - Vietnam Academy of Science and Technology has focused on researching and developing solar thermal reflective paint applied to prevent heat for petroleum storage tanks. The solar heat reflective coating works on the principle of diffuse reflection. Diffuse reflection occurs when incident beam radiation penetrates the powder and is reflected by the particle boundaries of the reflected particles.

Diffusion reflectivity depends on the shape, particle size and as the particle size decreases, the number of rays reflected at the particle boundaries will increase. As a result, the deep penetration of incident light decreases resulting in reduced absorption and increased reflection. The consequence will be a decrease in the absorbed part and an increase in the reflected part of the light. Highly diffuse reflective materials are usually pure metals such as Al, Ag and Cu; Metals with surface coatings such as AgS on Ag; Metal oxides CeO₂, TiO₂, MgO, Al₂O₃, and ZnO; Multilayer structures: TiO₂/Au/TiO₂; Silicon powder and intermediate sphere particles are coated with metal. 

Figure 4: Structure of heat-reflecting coating of micro(a) particle structure, nanoparticle structure interspersed between microparticles (b)

Heat reflectivity reaches more than 99% according to Japanese standards 

Absorbing and inheriting advanced science and technology achievements in the world in general and of Institute of Tropical Technology in particular, with the strong support of Vietnam Academy of Science and Technology through research and development projects, solar thermal reflective paint technology at Institute of Tropical Technology has been developed, continuously improved in quality, focusing on 2 main groups of criteria: heat reflection efficiency and weather durability. Currently, Institute of Tropical Engineering has completely mastered the technology of manufacturing heat-reflecting additives on the basis of nano-sized materials and applying them in making highly effective solar heat-reflecting paints. Solar thermal reflective paint products manufactured by the Institute fully meet strict foreign technical standards and are equivalent to imported products but have higher economic efficiency that have been applied in civil and defense projects (construction roofs, petroleum tanks, fishing vessels...).

With a structure consisting of highly heat-reflecting nanoparticles scattered interspersed between microparticles to create a tight structure in a transparent polymer substrate, the coating has a high reflectivity in the near-infrared region, so when using nano-reflective paint, the surface temperature of the steel tank can be reduced by up to 10-19^oC and the temperature in the tank is about 8-15^oC compared to when using common paint. In addition, the weather resistance of nanocoating is higher than 1500 hours of weather acceleration test.

Figure 5: Application of nano-reflective paint for petroleum tanks (type 5000 m³) with an area of 1400 m² at Cai Lan Petroleum Joint Stock Company, Quang Ninh

Figure 6. Application of nano-reflective paint at Petrol Depot 101-Border Guard in Tay Tuu, Nam Tu Liem, Hanoi

Figure 7: Application of nano-reflective paint at PETEC Hiep Hoa, Lien Chieu, Da Nang City

Figure 8: Experimental application of solar thermal reflective paint system on the basis of acrylic resin emulsion against heat part of the roof of Alexandre Yersin French School in Ngoc Thuy, Long Bien, Hanoi (In 2019) 

The solar thermal reflective paint products of Institute of Tropical Technology (ITT symbol) have been tested and evaluated by SuzukaFine (1 of the 5 largest paint companies in Japan, established since 1948) according to Japanese standard JIS K 5675 (High solar reflectant paint for roof) (Figure 9). The results of the analysis showed that samples of solar thermal reflective paints developed by the Institute of Tropical Engineering had much higher thermal reflectivity than domestic and international commercial solar thermal reflective paints. Specifically:

(1) In visible light regions, wavelengths from 300 – 780 nm: Reflectance is >= 99.73% and 99.73%. 

(2) In the near and far infrared regions, the wavelength is from 780 – 2500nm: The reflectance is >=98.93%. 

(3) In the region from visible to far infrared, wavelength 300 – 2500nm: Reflectance is >= 99.38%. [Thermal reflectivity measurement results for paint samples (symbols ITT15_230428_111538 and ITT23_230428_113647) of the Institute according to Japanese JIS standards]

Figure 9: Thermal reflectivity measurement results for nano-reflective paint samples of the Institute according to Japanese JIS standards

Suitable solar thermal reflective paint application for surfaces outside buildings, volatile liquid fuel/chemical storage tanks are an effective and low-cost solution to combat the urban heat island effect, which can save up to 40% of energy consumed by cooling equipment,  combating the loss of volatile fuels/chemicals, contributes to ensuring energy security, preventing climate change, contributing to sustainable development, towards the goal that Vietnam committed to at the United Nations climate change summit (COP26).

Translated by Phuong Ha
Link to Vietnamese version