Ethylene propylene copolymer (EPM), or a terpolymer with a diene (EPDM), is a type of synthetic rubber, which is characterised by a wide range of applications. The ‘E’ letter refers to ethylene, ‘P’ to propylene and ‘D’ to diene and ‘M’ refers to a kind of monomer with respect to its classification in ASTM standard D-1418. The M class includes rubbers having a saturated chain of the polymethylene type.

EPDM rubber, therefore, is a terpolymer of ethylene,propylene and a diene-component and the Dienes currently used in the manufacture of EPDM rubbers are dicyclopentadiene (DCPD), ethylidene norbornene (ENB) and vinyl norbornene (VNB). Hexadiene (HD) is rarely being used in making EPDM these days.

The ethylene and propylene monomers combine to form a chemically saturated, stable polymer backbone providing excellent heat, oxidation, ozone and weather aging. A third, nonconjugated diene monomer is terpolymerized in a controlled manner to maintain a saturated backbone and place the reactive unsaturation in a side chain available for vulcanization or polymer modification chemistry.

The two most widely used diene termonomers are primarily ethylidene norbornene (ENB) followed by dicyclopentadiene (DCPD).Each diene incorporates with a different tendency for introducing long chain branching or polymer side chains that influence processing and rates of vulcanization by sulfur or peroxide cures. Generally, ENB type is better heat resistant than DCPD type. Peroxide cure EPDM, boosted with coagents provide better heat resistant than sulphur/accelerator cured EPDM.

This polymer is the most water resistant rubber available, and this resistance is maintained to high temperatures (up to 180°C in steam with peroxide cured compound). The highest temperature resistance is achieved by using peroxide cured grades. It is thus used extensively under water cables (sea water as well). Before EPDM, Chloprene rubber (CR) was extensively used wherever weather resistance properties were important. Upon discovery of EPDM in 1963 , it quickly took over existing weather resistant market of Chloroprene rubber (CR).

Ethylene-propylene-diene rubber (EPDM) is one of the most widely used and highly-developing synthetic rubbers. EPDM business will reach US 6.9 b $ by end 1Q,2020. Currently, their total capacity is about 1.65m ton/ Yr. and it takes the third place in the world synthetic rubber consumption after styrene-butadiene and butadiene rubber. As of August 2019, there are 15 big companies in the world that produce EPDM.

In order to present a competitive landscape of the global EPDM market, key market players are witnessed as LANXESS AG (Germany), ExxonMobil Chemical (U.S.), Dow Elastomer (U.S.), Mitsui Chemical (Japan), Kumho Polychem (South Korea), Lion Copolymer (U.S.), Versalis (Italy), JSR Corporation (Japan), Jilin Chemical (China), SK Global Chemical (Japan), Nizhnekamsk Neftekhim Inc (Russia), and Sumitomo Chemical Company Ltd (Japan) have been profiled. With a huge number of EPDM manufacturers worldwide and with a number of different grades by each of these manufacturers, EPDM is one of the versatile elastomer in India now . EPDM has different grades in the industry based on :

• Mooney viscosity
• Type of diene content
• Percentage mole of diene content and
• Ethylene propylene ratio
• Bimodal Type

With current increase in EPDM uses , India now badly need EPDM manufacturing plant to protect its foreign currency. Another important application India need is compulsory application of EPDM based Roofing in rainy states to protect against damage of multistory buildings (Mumbai). EPDM has been used as a covering to waterproof roofing in western countries, Japan, China, Taiwan and countries in South East Asia. Major applications of EPDM are :

• Other than automobile glass-run channels, EPDM is also used in radiators, garden and appliance hose, tubing, pond liners, washers, belts, electrical insulation, vibrators, O-rings, solar panel heat collectors and speaker cone surrounds.
• It is also used as a medium for water resistance in electrical cable-jointing, geomembranes, rubber mechanical goods, plastic impact modification, thermoplastic etc.
• EPDM is used as blends in Butyl rubber for Inner-tube application.
• EPDM is used in PC side wall , black or white. Extensively used in color BC tyres for children.
• EPDM roofing is very popular in developed countries.
• With EPDM Roofing membranes rainwater harvesting is also very popular. EPDM roofing does not pollute the run-off rainwater.

Rubber roofing has the benefit that it does not pollute the runoff rain water. Water could be used for personal sanitation / gardenining / hygiene. White oil may be the best processing oil. They are manufactured in the form of calendared sheet and covered with a plastic such that its application on floor is easy upon removal of plastic and then they are applied in roof floor. EPDM rubber sheet can be installed either fully adhered, mechanically attached or ballasted, with the seams of the roofing system sealed with liquid adhesives or specially formulated tape. EPDM Waterproof Roofing system has delivered more than six decades of commercial roofing success by building upon a heritage of innovation in rubber polymer technology.

Dr Samir Majumdar, Rubber Consultant (India & Asia pacific), has served in leading tyre companies like JK Tyre, Kyoto Japan Tire, among others. He was technical and R&D head (Asia Pacific) in ExxonMobil. He has authored several research papers and technical books. smajumdar501234@yahoo.co.in

The Rubber Board, which is observing its 77th anniversary this year, organised a press conference to showcase a novel method developed by the Rubber Research Institute of India (RRII) for recovering high-quality rubber from skim latex.

The new technique creates rubber lumps by treating the skim latex with a specific chemical mixture for 24 hours, then allowing the acid to coagulate. After that, these lumps may be dried and turned straight into skim crepe. About 3–4 percent of the rubber used to make Centrifuged Latex (Cenex) is skim latex, a by-product of the process. Cenex is frequently used in the production of goods including balloons, condoms, and gloves. About 10 percent of the natural rubber produced in India is converted into Cenex via centrifugation, which is accomplished at more than 40 centrifuging facilities.

The current method for recovering skim rubber is the acid coagulation of skim latex, which produces a slurry of skim rubber. After being packed into many plastic sacks, this slurry is allowed to solidify and dewater for two weeks. Skim crepe is made by further processing the resultant skim powder. But this traditional approach is labour-intensive, unrefined and results in bad odours, and it only generates rubber of poor grade. It has also caused public outcry and legal conflicts in the vicinity of Cenex enterprises, and it presents difficulties for wastewater treatment facilities. With the innovative method created by RRII, plastic bags are no longer used and processing takes only twenty-four hours. In addition to improving environmental sustainability and guaranteeing full recovery of premium rubber from skim latex, it drastically reduces offensive odours.

The Federation of Latex Processors (FLP), a group of owners of centrifuged latex factories, has been granted access to this technology on a fee basis. Other organizations and Cenex units can also purchase it. The product is marketed as Indian Purified Skim Rubber (IPSR) by the Rubber Board, which is also working on a patent for the concept. Rubber companies nationwide have expressed a strong interest in employing IPSR in product manufacture as it provides a competitive edge because of its improved quality and reduced cost.

Several efforts to solve various problems that exist in the rubber value chain were also addressed at the press conference. At the press conference, it was revealed that a nationwide celebration of the Silver Jubilee of the National Institute for Rubber Training (previously the Rubber Training Institute) would be organised, with participation from all relevant parties. M Vasanthagesan IRS (Executive Director, Rubber Board), Dr T Siju (Rubber Production Commissioner), Dr M D Jessy (Director-in-Charge, Rubber Research Institute of India) and representatives of the Federation of Latex Processors were in attendance.

Kraton Corporation, a leading global sustainable producer of speciality polymers and high-value bio-based products derived from pine wood pulping co-products, has expanded its CirKular+ product line with the launch of CirKular+ Paving Circularity Series C5000 in line with its long-term vision to create innovative solutions for a sustainable tomorrow.

The CirKular+ Paving Circularity Series addresses the changing demands of the paving industry to use more reclaimed asphalt and lower greenhouse gas (GHG) emissions. It allows for the addition of up to 50 percent or more reclaimed asphalt to the asphalt mix in surface layers while enhancing performance and processability. It increases the modified asphalt's resilience while maintaining resistance to permanent deformation and lowering the pavement's lifetime carbon footprint.  C5000 satisfies requirements for asphalt surface materials and is compatible with Warm Mix Asphalt technology.

Pedro Lopes, Kraton Global VP of Strategic Marketing, Product Management and Supply Chain, said, “Launching the Paving Circularity Series is a testament to our commitment to sustainability and innovation. In Europe, the paving industry is actively working to increase circularity and reduce GHG emissions in alignment with the European Green Deal and the EU’s 2050 climate neutrality goals. The new series helps unlock value-added circularity by enabling polymer-modified bitumen (PMB) producers and contractors to increase the reuse of reclaimed asphalt, thereby reintegrating it back into the road surface layer.”

Perth-based CTS Tyre Recycling is forging ahead with its plans to reshape the options for disposal of end-of-life tyres in Western Australia.

The company, a part of the wider Cometti Group, a family-owned business with more than 40 years of experience in the tyre industry, has invested more than USD 40 million in a state-of-the-art recycling plant at Neerabup, north of Perth, that processes waste tyres into crumb rubber, tyre derived products, reusable high tensile steel wire and reusable textile. The company also made some additions to its management ranks and expanded its links with industry associations as it moves forward with its strategy. These tyres, along with all other sizes, will be remanufactured in the new Neerabup factory into new, high-value goods like load-restraining matting, gym matting, equestrian and farm matting and acoustic underlay.

Leigh Cometti, the company’s Managing Director, identified a potential to diversify into the recycling of end-of-life tyres, concentrating on some of the huge off-the-road tyres utilised in the mining services and agricultural industries. Over 90 percent of the bigger OTR tyres now in use in Western Australia are thought to end up in landfills. Tyres are commonly buried in pits left behind during excavation, which results in the greatest landfill disposals in the Pilbara area. The recycling programmes will lessen the need for more virgin products in addition to decreasing landfill discharge.

Cometti has brought on two seasoned senior level managers to support him as the company grows. Joseph Jeevaraj has joined as Chief Financial Officer, while Darren Rodwell has been named Chief Operating Officer. Both positions work for the Cometti Group, which also owns the Bunbury Trucks Sales and Service dealership, CTS People and Mechanics Recruitment.

Continental and the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH have extended their project to improve sustainability in smallholder natural rubber farming by three years. About 5,000 indigenous smallholders in West Kalimantan, Borneo, Indonesia, have already received training since 2018 on how to grow premium natural rubber in accordance with well-defined sustainability standards. Co-funded by Continental and the German Federal Ministry for Economic Cooperation and Development (BMZ), the initiative aims to engage an additional 1,000 smallholders by 2027.

Lack of knowledge and low farmer income are two major issues in natural rubber farming that are addressed by the Continental and GIZ initiative in the region of Kapuas Hulu, which is home to a UNESCO biosphere reserve. Farmers are taught sustainable agriculture practices and cultivation techniques through the training offered by Continental and GIZ. This enhances the rubber's quality, boosts yield, streamlines the supply chain and raises rubber producers' profits. Additionally, this aids in putting into practice the crucial subject of preserving or reviving biodiversity in the project region. Transparency is also guaranteed across the natural rubber supply chain, from the rubber tree to its usage in Continental's manufacturing, thanks to the implementation of a digital tracking system.

In addition to increasing local capacity, both the companies are actively assisting in enhancing smallholders' quality of life and encouraging environmentally friendly methods of growing natural rubber. The objectives of the EU Regulation on Deforestation-Free Supply Chains (EUDR) are clearly supported by Continental, which has long been actively dedicated to increased supply chain sustainability and transparency. In addition to Continental's tyre facilities, other manufacturers can purchase the sustainably sourced natural rubber produced as part of the project, and more partners are being invited to join.

Dr Michael Radke, Head of Sustainability in Purchasing, Continental, said, “As one of the largest tyre manufacturers in the world, we have a particular responsibility in the natural rubber supply chain. That is why we are committed at all levels and are building capacity locally. Over the past few years, together with GIZ, we have shown that we can make the natural rubber supply chain transparent and at the same time increase farmers’ incomes. Now we want to reach even more smallholders and create the framework conditions for the successes achieved to be sustained.”