Strong Against Fire, Yet Reusable... Development of 'Recyclable Flame-Retardant Material' [Reading Science]

KRICT Secures Processability, Flame Retardancy, and Recyclability with a Single Additive
Anticipated Applications in Electric Vehicles and UAM

A technology has been developed to overcome the limitations of flame-retardant composites that, while strong against fire, could not be reused once hardened. By adding a single inexpensive additive, both flame retardancy and processability are improved, and after use, over 90% of the additive can be removed, allowing the material to be reverted to its raw form. This is expected to contribute to the lightweighting and recyclability of next-generation mobility parts, such as electric vehicles and urban air mobility (UAM).

On August 18, the Korea Research Institute of Chemical Technology announced that the research team led by Dr. Jincheol Kim, Dr. Jieun Jeong, and Dr. Youngjae Jin from the Precision Chemical Research Center had developed a “self-reinforced composite” manufacturing technology that simultaneously delivers processability, flame retardancy, and recyclability by using a low-molecular-weight polyolefin additive.

Flame-retardant composite manufacturing process. Multiple layers of flame-retardant films and fiber reinforcements are stacked and thermally pressed, with constituent materials made from the same series to enhance recyclability. Provided by the research team.

For automotive parts, electronic circuit boards, and electrical outlets that must withstand fire, thermoset fiber-reinforced composites are typically used. While these materials retain their shape under heat, ensuring a high level of safety, they cannot be remelted once hardened, making reprocessing difficult. After use, most are either sent to landfills or incinerated at high temperatures, presenting a significant limitation.

To address this, the research team created self-reinforced composites by stacking layers of high-density polyethylene (HDPE) fibers and films that can be reprocessed when heated. The key was the incorporation of a small amount of low-cost, low-molecular-weight polyolefin in the film.

The Additive Plays 'Three Roles'... Achieves the Highest Flame-Retardant Rating

The additive softens the material, enabling the film and fiber to bond seamlessly, and also prevents flame retardant particles from clumping, ensuring they are spread evenly. It is also designed to be easily removable during the recycling process after use.

The application of this additive resulted in an approximately 40% improvement in adhesion between the film and the fiber compared to existing materials. Even when up to 40% flame retardant was added, the material achieved the highest 'V-0' grade in flame retardancy from Underwriters Laboratories (UL) in the United States, without any deterioration in mechanical properties. The V-0 rating means that even if the material ignites, it quickly self-extinguishes and does not transfer fire to adjacent combustible materials when molten drops fall.

Recycling performance was also enhanced. With conventional commercial additives, more than 40% of the additive remains after recycling, weakening the material properties. However, with the newly developed material, over 90% of the additive could be removed through a washing process. This yielded high-purity recycled raw materials with color and strength nearly equivalent to new plastic.

Research team at the Precision Chemistry Research Center, Korea Research Institute of Chemical Technology. From the left, Hyungeun Bae, Senior Researcher; Haemin Jung, Senior Researcher; Youngjae Jin, Senior Researcher; Jincheol Kim, Principal Researcher and Research Director; Hyochul Jung, Principal Researcher; Jieun Jung, Senior Researcher; Youngil Park, Principal Researcher. Photo provided by KRICT

The research team plans to conduct further studies to verify whether flame retardants accumulate through repeated recycling and additional flame-retardant testing. They also aim to collaborate with industrial partners for property evaluations and demonstration studies, with the goal of applying these materials as structural components for next-generation mobility platforms such as electric vehicles and UAM.

Jincheol Kim, Principal Researcher at the Korea Research Institute of Chemical Technology, said, “With a single inexpensive additive, we have addressed the chronic challenge of simultaneously improving processability and recyclability in flame-retardant composites. This innovation is expected to promote resource circulation and help reduce the weight of components for next-generation mobility platforms, including electric vehicles and urban air mobility.”

The research results were published in the international journal 'Composites Part B' in March 2026.

This content was produced with the assistance of AI translation services.