Media Resouces
NUS researchers successfully engineer the world’s first aerogels made from scrap rubber tyres
18 Mar 2020
  • Patented technology cuts rubber waste; Novel rubber aerogels are ultra-light, highly absorbent, durable, and traps heat and sound
  • Mapletree Investments commits S$155,000 for further research and public education of green aerogel technology 
     
  • SINGAPORE – A team of researchers from the National University of Singapore (NUS) has achieved a major technological breakthrough by converting waste rubber tyres into super-light aerogels that have a wide range of applications. This is the first time that aerogels are made from waste rubber tyres. The new rubber aerogels demonstrate remarkable properties – they are extremely light, highly absorbent, very durable, and they are also very efficient at trapping heat and sound. 

    By upcycling waste rubber into products of a higher commercial value, this new technology promotes a wider use of scrap tyres, and offers an eco-friendly way to recycle used rubber. This novel technology was published in the print version of scientific journal Colloids and Surfaces A: Physicochemical and Engineering Aspects in September 2019, and a patent has been filed. 

    To boost the research efforts of the team and raise public awareness of recycling, Mapletree Investments, a leading real estate developer with a strong focus on environmental sustainability, has recently made a gift of S$155,000 to NUS.  

    Scrap tyres – A significant waste problem

    Every year, about 1 billion scrap tyres are generated worldwide. Rubber tyres are highly durable and non-biodegradable. Only 40 per cent are recycled into low-value-added products, while 49 per cent are incinerated to generate energy, and at least 11 per cent end up in landfills. Although landfills are commonly practised, landfills sites are running out and there is also a risk of the consequential leachate causing environmental pollution. Furthermore, burning rubber produces toxic substances that pose health and safety concerns. 

    “Although 40 per cent of waste rubber tyres are recycled, the rate of recycling worldwide remains low because processing used rubber is costly and energy-intensive, coupled with a lack of monetary incentive. Our team has decided to focus on creating rubber aerogels from used rubber tyres because they are a cheap and abundant source of raw materials. By converting waste rubber tyres into high-value aerogels, we could enhance the monetary incentive for recycling rubber and in turn, cut down rubber waste,” explained Associate Professor Duong Hai-Minh, who leads the research team from the Department of Mechanical Engineering at NUS Faculty of Engineering.

    Mr Edmund Cheng, Mapletree Chairman, said, “Mapletree has always placed great emphasis on integrating sustainable designs into our developments. This project which aims to turn plastic rubber waste into aerogel materials via green technology is aligned to our commitment to reduce negative environmental impact. We are excited that part of the support will also fund the refurbished lab facility for applied research and education on the potential of recycling technology. It is our hope that through education, one of our key corporate social responsibility pillars, there will be more awareness on environmental issues.”

    Simple, cost-effective and eco-friendly production process 

    To create the rubber aerogels, recycled car tyre fibres are first blended into finer fibres. These fine rubber fibres are then soaked in water and very small amount of chemical cross-linkers. Next, the mixture of rubber fibres and eco-friendly solvents is dispersed uniformly using a stirrer for 20 minutes. The uniform suspension gel is then freeze-dried at minus 50 degrees Celsius for up to 12 hours to produce rubber aerogels. 

    Assoc Prof Duong said, “The fabrication process is simple, cost-effective and eco-friendly. The entire production process takes between 12 to 13 hours to complete and it only cost less than S$10 to produce a sheet of rubber aerogel that is 1 sqm in size and 1cm thick. The process can also be easily scaled up for mass production. This makes rubber aerogels a commercially attractive product.” 

    Highly versatile rubber aerogels 

    The novel rubber aerogels created by the NUS team possess remarkable properties for many applications:

    • Extremely light and stiffer than commercial foam
    • Highly porous: This makes rubber aerogels good absorbents for removal of spilled oil. They are two times more absorbent than conventional absorbents such as the polypropylene mat.
    • Excellent sound adsorption: Rubber aerogels are 27 per cent more effective than the commercial foam absorber with the same thickness.
    • Excellent heat insulation: Rubber aerogels have high heat resistance. A piece of rubber aerogel with a thickness of one inch (2.54 cm) has a heat transfer limit that is equivalent to 25 standard glass window panes.
    • Highly durable: Most aerogels are extremely brittle and friable (i.e. they tend to fragment and pulverise), but rubber aerogels can spring back to its original shape after compression. This unique property makes them suitable as insulation material for industrial purposes such as in subsea systems, oil refineries and industrial buildings, and also in homes, refrigerators, as well as personal items such as jackets and shoe insoles.
    • When coated with a chemical called methoxytrimethylsilane, the rubber aerogels become extremely water-repellent and they can be used to prevent moisture from corroding or damaging insulation equipment.

    “Potential markets of aerogels are huge. For example, vehicle noise and thermal comfort are vital in vehicle designs - the global automotive heat and sound insulation solution market are expected to reach US$3.2 billion by 20221. In addition, the global oil spill management market is expected to reach US$182.7 billion by 20252,” added Professor Nhan Phan-Thien, who is a senior member in the research team.

    Commercialisation and new applications

    Assoc Prof Duong, Prof Nhan and their team are looking forward to realising the positive environmental impact of aerogels by working with Mapletree and industry partners to commercialise and scale up this novel technology. With the generous contribution from Mapletree, the NUS team will be able to conduct further studies to enhance the performance of the rubber aerogels, explore other applications as well as using other types of waste materials to convert into aerogels.

    Photo credit: National University of Singapore

     

    A team of researchers from the National University of Singapore, led by Associate Professor Duong Hai-Minh (front row, first from left) and Prof Nhan Phan-Thien (front row, centre), developed the world’s first aerogels made from scrap rubber tyres.

    MEDIA CONTACTS

    Grace Sung    

    Senior Executive, Corporate Communications  
    Tel: +65 6804 8474  
    Email: grace.sung@mapletree.com.sg
     
       

     

    ABOUT MAPLETREE

    Mapletree is a leading real estate development, investment, capital and property management company headquartered in Singapore. Its strategic focus is to invest in markets and real estate sectors with good growth potential. By combining its key strengths, the Group has established a track record of award-winning projects, and delivers consistent and high returns across real estate asset classes.

    Mapletree currently manages four Singapore-listed real estate investment trusts (REITs) and six private equity real estate funds, which hold a diverse portfolio of assets in Asia Pacific, Europe, the United Kingdom (UK) and the United States (US).

    As at 31 March 2019, Mapletree owns and manages S$55.7 billion of office, retail, logistics, industrial, residential and lodging properties.

    The Group’s assets are located across 12 markets globally, namely Singapore, Australia, China, Europe, Hong Kong SAR, India, Japan, Malaysia, South Korea, the UK, the US and Vietnam. To support its global operations, Mapletree has established an extensive network of offices in these countries.

    For more information, please visit www.mapletree.com.sg.

     

    ABOUT NATIONAL UNIVERSITY OF SINGAPORE (NUS)

    The National University of Singapore (NUS) is Singapore’s flagship university, which offers a global approach to education, research and entrepreneurship, with a focus on Asian perspectives and expertise. We have 17 faculties across three campuses in Singapore, as well as 12 NUS Overseas Colleges across the world. Close to 40,000 students from 100 countries enrich our vibrant and diverse campus community. 
     
    Our multidisciplinary and real-world approach to education, research and entrepreneurship enables us to work closely with industry, governments and academia to address crucial and complex issues relevant to Asia and the world. Researchers in our faculties, 29 university-level research institutes, research centres of excellence and corporate labs focus on themes that include energy, environmental and urban sustainability; treatment and prevention of diseases common among Asians; active ageing; advanced materials; as well as risk management and resilience of financial systems. Our latest research focus is on the use of data science, operations research and cybersecurity to support Singapore's Smart Nation initiative.

    For more information on NUS, please visit www.nus.edu.sg