Scientists Advance Hemp-Derived Plastic for Plastic Pollution Alternatives
Researchers have developed a non-toxic hemp-derived plastic alternative that stretches up to 1,600% of its size, offering a new route for packaging and other products tied to plastic pollution. The material was described in a study recently published in Chem Circularity and tested as a hemp-based plastic film for wider use.
Gregory Sotzing on hemp-derived plastics
Gregory Sotzing, a professor in the UConn Department of Chemistry and an author on the study, said, “We are finding new ways to use the entire plant.” Sotzing also said, “Current day polycarbonate is made from bisphenol-A, a known endocrine disruptor. The hope here is that cannabidiol (CBD) can take the place of bisphenol-A found in today’s processed plastics,” linking the hemp-derived approach to a material that is already used in common plastic products.
The team said the hemp material is suitable for transparent plastic films, coatings, and other products now made from petroleum-based materials such as polyethylene terephthalate, or PET. PET is widely used in single-use water bottles, food packaging, and substrates for flexible electronics, and it requires large quantities of crude oil and natural gas.
Purdue University processing framework
Mukerrem Cakmak, an author at Purdue University, said, “Our work has established CBD-based colycarbonates as sustainable replacements for widely used thermoplastics such as PET.” Cakmak added, “We have developed a rigorous processing science framework that links molecular architecture to melt processability, orientation development, and stretchability without compromising manufacturability.”
The researchers said they achieved melt processability in a hemp-based polycarbonate for the first time, and they also tested the processing parameters needed to give the film the right structure and properties for wider use. Sotzing said, “Very few, if any, plastics made from natural resources have this quality,” referring to the material’s high glass transition temperature.
Petroleum plastics and PET
The study places the hemp material against a plastic economy built around PET, a petroleum-based product that the researchers said is common in packaging and flexible electronics. When discarded, PET breaks down into tiny particles called microplastics, which is part of the push to find alternatives that can be made from plant-based feedstocks without losing stretchability or practical processing characteristics.
Sotzing also said, “This polycarbonate has, as a smooth film, a very high contact angle with water. We were not expecting our polyCBD-carbonate to have a higher contact angle than most polyolefins,” describing one of the film’s performance traits. For manufacturers looking at packaging, coatings, or film products, the immediate question is whether this hemp-derived material can scale without giving up the properties that make PET so useful in the first place.
