Plastic from wood

March 03, 2020

The biopolymer lignin is a by-product of papermaking and a promising raw material for manufacturing sustainable plastic materials. However, the quality of this naturally occurring product is not as uniform as that of petroleum-based plastics. An X-ray analysis carried out at DESY reveals for the first time how the internal molecular structure of different lignin products is related to the macroscopic properties of the respective materials. The study, which has been published in the journal Applied Polymer Materials, provides an approach for a systematic understanding of lignin as a raw material to allow for production of lignin-based bioplastics with different properties, depending on the specific application.

Lignin is a class of complex organic polymers and responsible for the stability of plants, stiffening them and making them "woody" (i.e. lignification). During paper production, lignin is separated from cellulose. Lignin forms so-called aromatic compounds, which also play a key role in manufacturing synthetic polymers or plastics. "Lignin is the biggest source of naturally occurring aromatic compounds, but until now it has been viewed by the paper industry primarily as a by-product or a fuel," explains Mats Johansson from the Royal Institute of Technology (KTH) in Stockholm, who led the research team. "Millions of tonnes of it are produced every year, providing a steady stream of raw material for new potential products."

Some first applications of hard lignin-based plastics (thermosets) already exist. However, their properties often vary and until now it has been difficult to control them specifically. The Swedish team has now shed light on the nanostructure of different fractions of commercially available lignin at DESY's X-ray source PETRA III. "It turns out that there are lignin fractions with larger and smaller domains," reports the principle author Marcus Jawerth, of Stockholm's KTH. "This can offer certain advantages, depending on the particular application: it makes the lignin harder or softer by altering the so-called glass transition temperature at which the biopolymer adopts a viscous state."

Among other things, the X-ray analysis revealed that those types of lignin whose central benzene rings are arranged in the shape of a T are particularly stable. "The molecular structure affects the macroscopic mechanical properties," explains DESY's Stephan Roth, who is in charge of the P03 beamline at which the experiments were conducted and who co-authored the paper. "This is the first time this has been characterised." As a natural product, lignin comes in numerous different configurations. Further studies are needed to provide a systematic overview of how different parameters affect the properties of the lignin. "This is very important in order to be able to manufacture materials reproducibly, and in particular to predict their properties," says Roth, who is also a professor at KTH Stockholm. "If you want to use a material industrially, you need to understand its molecular structure and know how this is correlated with the mechanical properties."

According to Jawerth, up to two thirds of the lignin produced during the paper production process could be turned into polyesters and serve as a starting material for making plastics. "Along with cellulose and chitin, lignin is one of the most ubiquitous organic compounds on Earth and offers enormous potential for replacing petroleum-based plastics," says the scientist. "It's far too valuable to simply burn it."
The KTH Stockholm, the Swiss Federal Institute of Technology in Lausanne, the Swedish research institute RISE and DESY were involved in the research.

DESY is one of the world's leading particle accelerator centres and investigates the structure and function of matter - from the interaction of tiny elementary particles and the behaviour of novel nanomaterials and vital biomolecules to the great mysteries of the universe. The particle accelerators and detectors that DESY develops and builds at its locations in Hamburg and Zeuthen are unique research tools. They generate the most intense X-ray radiation in the world, accelerate particles to record energies and open up new windows onto the universe. DESY is a member of the Helmholtz Association, Germany's largest scientific association, and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent).


Mechanical and Morphological Properties of Lignin-based Thermosets; Marcus E. Jawerth, Calvin J. Brett, Cédric Terrier, Per T. Larsson, Martin Lawoko, Stephan V. Roth, Stefan Lundmark & Mats Johansson; „ Applied Polymer Materials", 2020; DOI: 10.1021/acsapm.9b01007

Deutsches Elektronen-Synchrotron DESY

Related Lignin Articles from Brightsurf:

Utilizing a 'krafty' waste product: Toward enhancing vehicle fuel economy
Researchers from Kanazawa University have chemically modified Kraft lignin -- ordinarily considered in the paper industry to be a waste product -- and used it to produce quality carbon fiber.

CRISPRing trees for a climate-friendly economy
Researchers led by prof. Wout Boerjan (VIB-UGent Center for Plant Systems Biology) have discovered a way to stably finetune the amount of lignin in poplar by applying CRISPR/Cas9 technology.

New process boosts lignin bio-oil as a next-generation fuel
A new low-temperature multi-phase process for upgrading lignin bio-oil to hydrocarbons could help expand use of the lignin, which is now largely a waste product left over from the productions of cellulose and bioethanol from trees and other woody plants.

Lightweight green supercapacitors could charge devices in a jiffy
In a new study, researchers at Texas A&M University have described their novel plant-based energy storage device that could charge even electric cars within a few minutes in the near future.

From biopaste to bioplastic
Forest scientists develop innovative wood-based materials for 3D printing.

Key technology for mass-production of lignin-bio-aviation fuels for reducing greenhouse gas
The team, led by Dr. Jeong-Myeong Ha of the Clean Energy Research Center at the Korea Institute of Science and Technology(KIST), has developed a technology that can be used to mass-produce aviation-grade fuels from wood wastes.

Researchers develop sustainable method for extracting vanillin from wood processing waste
Scientists at Johannes Gutenberg University Mainz (JGU) in Germany have developed a new sustainable method of extracting the flavoring agent vanillin from lignin, a component of wood.

A model for better predicting the unpredictable byproducts of genetic modification
Researchers are interested in genetically modifying trees for a variety of applications, from biofuels to paper production.

A novel biofuel system for hydrogen production from biomass
A recent study, affiliated with South Korea's Ulsan National Institute of Science and Technology (UNIST) has presented a new biofuel system that uses lignin found in biomass for the production of hydrogen.

Plastic from wood
The biopolymer lignin is a by-product of papermaking and a promising raw material for manufacturing sustainable plastic materials.

Read More: Lignin News and Lignin Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to