U.S. Develops New Thermoplastic ABL

[Chinese Packaging Network News] has heat softening, cooling and hardening properties of plastic, collectively referred to as thermoplastics. Most plastics used in our daily lives fall into this category. When heated, it softens and flows, and cooling hardens. This process is reversible and can be repeated.

Recently, researchers at the US Department of Energy's Oak Ridge National Laboratory replaced styrene in abs plastics with plant-derived lignin and developed a new and better thermoplastic plastic, ABL (acrylonitrile-butadiene-lignin). The initials).

They invented a solvent-free production process that interconnects nano-sized lignin dispersed in a synthetic rubber matrix to produce a fusible, moldable tough material that is at least ten times tougher than abs. ABL can also be recycled and still perform well after melting three times. The results of this study, published in the magazine Advanced Functional Materials, may provide different manufacturers with cleaner, cheaper materials.

"The new thermoplastics perform better than commercial plastics such as ABS," said the author of the article, Amit Naskar, who has filed for the new material with the first author, Chau D. Tran. “We can call it green, because 50% of its parts are renewable, which makes its commercialization process less demand for petrochemicals.”

In order to develop this material, Oak Ridge National Laboratory team needs to solve several problems: whether it can overcome the diversity of lignin raw materials to obtain superior performance plastic products? Can lignin integrate smoothly into soft polymer matrix? How to better understand the chemical and physical properties of lignin-derived polymers in order to better control their performance? Can lignin-derived polymers be modified?

"Lignin is a very fragile natural polymer, so it needs to be toughened," Naskar explained. One of the team's main goals is to produce enough tough industrial polymers so that they do not break during deformation.

Various lignin also have different thermal stability. The scientists evaluated lignin from wheat straw, softwood (such as pine) and hardwood (such as oak). They found that the hardwood-derived lignin has the best thermal stability, and some types of softwood lignin can also be in the molten state. keep it steady.

Next, researchers need to combine lignin with a soft polymer matrix. Typically, chemists achieve this by synthesizing the polymer in the presence of a solvent. However, because lignin and synthetic rubbers containing acrylonitrile and butadiene (known as nitrile rubbers) all have chemical groups with inhomogeneous distribution of electrons, interactions are likely to occur, so Naskar and Chau Tran try to work in solvent-free conditions. The two substances are fused in the molten state.

At the same time, the researchers are also optimizing the composition and production process of ABL plastics. They found that the synthetic rubber matrix with 41% acrylonitrile can achieve the best balance of toughness and rigidity for ABL. The mixing temperature of each component is between 140 and 160 degrees Celsius. The best time effect.

Plastic is probably one of the most widely used materials created by chemists. Take ABS plastic as an example. This thermoplastic polymer consists of acrylonitrile, butadiene, and styrene. It is light and strong, and is widely used in automobile insurance. Bars, ventilation ducts, safety helmets, kitchen appliances, Lego bricks, and many more. However, the raw materials needed to produce such plastics need to be obtained from petroleum-derived chemicals, which is not quite right with the current emphasis on sustainable development.

The researchers found that the final material consisted of lignin formed 5-100 nm flakes and a high-modulus rubber interface. The final material yield stress was as high as 15–45 MPa. The team's future research will explore the possibility of using different raw materials, especially biomass industrial waste, for ABL.