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

Specialty material solutions provider Trinseo has announced that it has established a tool that provides cradle-to-gate Product Carbon Footprint (PCF) and Life Cycle Assessment (LCA) data.

The tool features nearly 6,000 Trinseo products, which can be accessed by customers to know the exact carbon footprint associated with a particular product.

On the other hand, LCA assess the environmental impacts of a product beyond PCF, including the use of resource, human health, ecological impacts, and more. This data the company said is crucial for understanding the environmental impact of products, allowing effective material comparison, enhancing R&D innovations, and ultimately contributing to a customer’s sustainability goals.

The Trinseo’s PCF and LCA tool follow the TfS guidelines and the latest European Product Environmental Footprint (PEF) methodology and are compliant with the GHG Protocol and ISO standards 14040, 14044, and 14067.

Longxing Chemical Stock has announced plans to acquire 100 percent of China Rubber (Chongqing) Carbon Black from CSRC (Singapore), according to a filing with the Shenzhen Stock Exchange.

The target company is a key producer of carbon black, a vital material used in the manufacture of automobile tyres and other rubber products.

Longxing Chemical initially proposed purchasing a 55 percent stake in the company, with its actual controller, Liu Jiangshan, set to acquire the remaining 45 percent. However, the plan has been revised, and Liu Jiangshan will no longer participate in the acquisition.

The updated proposal is still in the planning stage, with specific terms and conditions yet to be finalised. Further details are expected as the process progresses.

PPG has formally announced the completion of the sale transaction of its silicas products business for USD 310 million (approximately) in pre-tax proceeds to Qemetica, a leading manufacturer of soda ash, silicates and other speciality chemicals.

The deal covers PPG’s precipitated silicas manufacturing plants in Lake Charles, Louisiana and Delfzijl, The Netherlands. Additionally, Qemetica will lease silicas production and R&D activities from PPG in Barberton, Ohio and Monroeville, Pennsylvania.

Tim Knavish, Chairman and CEO, PPG, said, “We are pleased to complete this transaction with Qemetica, and I want to thank the silicas products business employees for their dedication and commitment to the business and to PPG customers throughout the years.”

Kraton Corporation, a leading global sustainable producer of speciality polymers and high-value bio-based products derived from pine wood pulping co-products, has increased the price of its SIS polymer products by USD 330 per MT.

The company said the price hike was due to continued increase in raw materials and process chemicals.

The price hike will be global and comes into effect from 1 January 2025.