The biodegradable plastics could replace conventional plastics that are used to make stretch wrap for large cargo items, food containers, eating utensils and other plastics used at sea, the researchers say. The biodegradable plastic has not yet been tested in freshwater. The development was described today at the 233rd national meeting of the American Chemical Society.
“There are many groups working on biodegradable plastics, but we’re one of a few working on plastics that degrade in seawater,” says study leader Robson F. Storey, Ph.D., a professor of Polymer Science and Engineering at USM, located in Hattiesburg, Miss. “We’re moving toward making plastics more sustainable, especially those that are used at sea.”
Conventional plastics can take years to break down and may result in byproducts that are harmful to the environment and toxic to marine organisms, conditions that make their disposal at sea hazardous. The new plastics are capable of degrading in as few as 20 days and result in natural byproducts that are nontoxic, Storey and his associates say. Their study is funded by the Naval Sea Systems Command (NAVSEA), which is supporting a number of ongoing research projects aimed at reducing the environmental impact of marine waste.
The new plastics are made of polyurethane that has been modified by the incorporation of PLGA [poly (D,L-lactide-co-glycolide)], a known degradable polymer used in surgical sutures and controlled drug-delivery applications. Through variations in the chemical composition of the plastic, the researchers have achieved a wide range of mechanical properties ranging from soft, rubber-like plastics to hard, rigid structures, depending on their intended use.
When exposed to seawater, the plastics degrade via hydrolysis into nontoxic products, according to the scientists. Depending on the composition of the plastics, these compounds may include water, carbon dioxide, lactic acid, glycolic acid, succinic acid, caproic acid and L-lysine, all of which can be found in nature, they add.
Because the new plastics are denser than saltwater, they have a tendency to sink instead of float, Storey says. That feature also could prevent them from washing up on shore and polluting beaches, he notes.
The plastics are undergoing degradation testing at the U.S. Army Natick Soldier Research, Development, and Engineering Center in Natick, Mass., and in the Gulf of Mexico at the USM Gulf Coast Research Laboratory in Ocean Springs, Miss. Initial results have been favorable, Storey says.
The plastics are not quite ready for commercialization. More studies are needed to optimize the plastics for various environmental conditions they might encounter, including changes in temperature, humidity and seawater composition, Storey says. There also are legal hurdles to overcome, since international maritime law currently forbids disposal of plastics at sea.
Charmayne Marsh | EurekAlert!
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine