Source: Rubber Technology Network

The third-generation material for rubber is bio-based rubber. With its environmentally friendly, sustainable, and renewable properties, this new material is gradually becoming a favorite in the rubber industry and holds great promise to lead a green revolution in rubber materials in the future.

As a widely used material—from natural rubber to synthetic rubber—rubber has already undergone two generations of transformation. However, as global environmental issues become increasingly prominent and the concept of sustainable development takes root in people’s minds, traditional rubber materials can no longer meet the demands of modern society. Thus, bio-based rubber—a third-generation rubber material—has emerged, gaining rapid popularity in the field of materials science thanks to its environmentally friendly, sustainable, and renewable characteristics.

Bio-based rubber, also known as bio-rubber or biomass rubber, is a new type of rubber produced from renewable biological resources as the primary raw materials through methods such as biofermentation or chemical synthesis. Compared to conventional petroleum-based rubber, bio-based rubber boasts a lower carbon footprint, superior biodegradability, and greater renewability, aligning with the green development trend of modern society.

The development of bio-based rubber can be traced back to the early 21st century. With the rapid advancement of biotechnology and humanity’s growing pursuit of renewable energy sources, an increasing number of research institutions and enterprises have begun to devote themselves to the research, development, and production of bio-based rubber. After years of dedicated effort, bio-based rubber has now been widely adopted in fields such as automobiles, tires, footwear materials, and wires and cables, yielding remarkable environmental and economic benefits.

However, the development of bio-based rubber still faces several challenges. First, the production cost of bio-based rubber is relatively high, mainly because the technologies for sourcing and processing raw materials are not yet fully mature. Second, the performance and stability of bio-based rubber still need to be improved to meet the demands of more diverse applications. In addition, the market promotion and application of bio-based rubber also require greater policy support and financial investment.

Nevertheless, the future prospects for bio-based rubber remain extremely promising. As technology continues to advance and costs continue to decline, bio-based rubber is poised to replace traditional petroleum-based rubber in an increasing number of applications, eventually becoming the dominant material in the rubber industry. Meanwhile, with the world placing greater emphasis on sustainable development and the rise of the green economy, bio-based rubber will also play a crucial role in driving green growth and addressing climate change.

In short, the third-generation rubber material—bio-based rubber—is leading a green revolution in the field of rubber materials thanks to its unique advantages and tremendous potential. Looking ahead, we have every reason to believe that bio-based rubber will become a key driving force behind sustainable development and the building of a green economy.

Natural rubber is produced by processing latex extracted from plants such as rubber trees and guayule. Synthetic rubber, on the other hand, is obtained through polymerization reactions involving various monomers. Non-grain bio-based synthetic rubber refers to rubber materials synthesized using non-grain biomass resources—such as crop straw and corn cobs—as raw materials, via technologies like microbial fermentation. This type of rubber does not compete with arable land or consume food crops, and its carbon emissions during production are 50% to 80% lower than those of petroleum-based synthetic rubber. It represents a key material for addressing the dual challenges of “oil dependence” and “food security.”
Research on the Substitution of Bio-based Rubber for Petroleum-based Rubber

Same-structure replacement

The biggest difference between bio-based and petroleum-based rubber lies in their raw material sources. Bio-based rubber is derived from sources such as potatoes, corn, and straw. For example, if ethylene and propylene derived from bio-based feedstocks are used to produce ethylene-propylene rubber, the resulting product is bio-based ethylene-propylene rubber. On the other hand, if ethylene and propylene derived from petroleum-based feedstocks are used to produce ethylene-propylene rubber, the resulting product is petroleum-based ethylene-propylene rubber. When the structural composition remains the same—meaning that the molecular structure, monomer polymerization methods, product performance, and downstream application fields are all identical—the only difference lies in the source of the raw materials.

New structure replacement

This means that the rubber molecular structures prepared are novel and distinct from those of conventional, widely used synthetic rubbers. Take, for example, the bio-based polyester rubber and bio-based itaconate rubber developed by our team: compared to traditional rubbers, these bio-based rubbers exhibit similar mechanical properties and application areas, yet they also possess unique characteristics—such as oil resistance and biodegradability.

Industrialization of bio-based rubber materials

Jingbo Zhongju: 10,000 tons/year of non-grain bio-based rubber

In November 2024, the 10,000-ton-per-year non-grain bio-based rubber production line of Jingbo Zhongju was approved for construction, marking the entry of non-grain bio-based rubber products into the ten-thousand-ton-scale industrialization phase. This bio-based itaconate ester rubber project, now entering industrialization, aims to establish a complete industrial chain for non-grain bio-based synthetic rubber. The project uses agricultural waste—corn cobs—as raw material to produce itaconate ester rubber, combining technological innovation with environmental benefits.

“Compared to conventional petroleum-based synthetic rubber, producing one ton of bio-based itaconate rubber can reduce CO₂ emissions by approximately 1.4 tons, and the bio-based carbon content of the product can range from 20% to 100%,” Liu Xiao explained. Currently, the project has obtained ISCC PLUS certification for the entire value chain, fully implementing the concept of green development—from raw material sourcing to the production process. It is understood that this achievement has already been applied and promoted in products across various fields, including high-end footwear materials, protective gloves, and tires.

The Henghui Security’s annual production project for 110,000 tons of biodegradable polyester rubber is being steadily advanced under a “single-phase planning, three-phase construction” model. Specifically, the first-phase project with a capacity of 10,000 tons officially broke ground in August 2024 and is currently progressing smoothly according to the established schedule, with efforts underway to achieve stable production of qualified rubber compounds that meet the designed performance specifications at an early date.

Bio-based ternary ethylene propylene diene monomer (EPDM) rubber produced by Arlanxeo.

The raw materials are sourced from sugarcane: first, sucrose is produced from sugarcane; then, ethanol is made from the sugar; next, ethanol is converted into ethylene. Meanwhile, ethanol undergoes an isomerization reaction with 2-butene to produce bio-based propylene, which is ultimately polymerized into ternary ethylene-propylene-diene rubber (EPDM). Currently, Arlanxeo offers six different grades of bio-based EPDM, used in automotive components, window and door sealing materials, shoe midsoles, as well as in artificial turf and synthetic running tracks.

Dow Chemical

A bio-based EPDM rubber was launched during the German Rubber Expo. Made from bio-waste residues sourced from other industries, it claims to help customers reduce their carbon footprint.

This type of ethylene propylene diene monomer (EPDM) rubber can be used in automotive weather-sealing gaskets, hoses, architectural profiles, roofing membranes, and wire and cable applications, thereby contributing to the development of the construction and building industries beyond the automotive sector.

In 2021, Beijing University of Chemical Technology successfully developed a new functionalized bio-based itaconate-butadiene rubber. The team led by Professors Zhang Liqun and Wang Runguo from Beijing University of Chemical Technology used bio-based itaconate esters and butadiene monomers as raw materials and, through copolymerization and functionalization modification techniques, successfully created a new generation of high-performance, functionalized bio-based itaconate-butadiene rubber. This innovative achievement not only lays a solid foundation for large-scale engineering applications but also realizes the efficient value-added utilization of biomass resources, thereby promoting the green transformation and sustainable development of the rubber industry. By designing molecular structures, the team from Beijing University of Chemical Technology has achieved the industrial production of high-performance bio-based rubber, obtained multiple patents, and gained international recognition.

Bio-based rubber can be divided into two categories: natural rubber and bio-based synthetic rubber. The latter, in turn, can be further classified into bio-based conventional synthetic rubber and novel bio-based synthetic rubber.

China’s natural rubber tree yield is very low. However, natural rubber can also be extracted from two plant species unique to China: dandelion and Eucommia ulmoides. Although these two plants don’t have particularly high rubber content, we can use genetic modification techniques to increase their rubber yield. Additionally, we can optimize the rubber-extraction process to further boost production efficiency. This is the core issue at hand.

Bio-based conventional rubber is rubber prepared by replacing petroleum-based raw materials with bio-based raw materials of the same structure. Currently, internationally there is a growing trend toward bio-based ethylene, bio-based butadiene, and bio-based isoprene—among others. By substituting petroleum-based olefin monomers with bio-based olefin monomers, it becomes possible to achieve low-carbon and environmentally friendly end products.

The advantage of this type of rubber is that it does not require market validation and can directly replace existing petroleum-based rubbers. Its main current challenges are the high cost of bio-based olefin feedstock and the complexity of the production process, which limit its applications. The key focus for the development of this type of rubber lies in how to improve the conversion rate of bio-based olefins and reduce costs by optimizing bio-refining processes.

The development direction for new bio-based synthetic rubbers lies in leveraging molecular structure design to create an even greater variety of product grades. Since there are no established reference materials for these new rubber types, it is crucial to tailor the molecular structures specifically to target markets—this represents a key research focus in this field. Additionally, it is essential to accelerate market validation of these rubbers and promptly scale up production to the tens-of-thousands-ton level, thereby facilitating their commercialization.

Currently, there is extensive research focused on obtaining raw material chemicals through various biological fermentation processes and on designing and synthesizing new bio-based elastomers. If all currently petroleum-based raw materials could be sourced via biofermentation, then all existing polymer materials could potentially become bio-based as well.