New Process to Develop Microbe-derived Polymer to Curb Plastic Pollution

According to the United Nations, plastic accounts for up to 90 percent of all the pollutants in our oceans, yet there are few comparable, environmentally friendly alternatives to the material. 

New Sustainable Tech Developed by TAU Researchers

Now, a new Tel Aviv University study describes a process to make bioplastic polymers that don't require land or fresh water — resources that are scarce in much of the world. The polymer is derived from microorganisms that feed on seaweed. It is biodegradable, produces zero toxic waste and recycles into organic waste.

The invention was the fruit of a multidisciplinary collaboration between Dr. Alexander Golberg of TAU's Porter School of Environmental and Earth Sciences and Prof. Michael Gozin of TAU's School of Chemistry. Their research was recently published in the journal Bioresource Technology.

Using Seaweed as "Fuel" for Decontamination

"Plastics take hundreds of years to decay. So bottles, packaging and bags create plastic 'continents' in the oceans, endanger animals and pollute the environment," says Dr. Golberg. "Plastic is also produced from petroleum products, which has an industrial process that releases chemical contaminants as a byproduct."

"A partial solution to the plastic epidemic is bioplastics, which don't use petroleum and degrade quickly. But bioplastics also have an environmental price: To grow the plants or the bacteria to make the plastic requires fertile soil and fresh water, which many countries, including Israel, don't have. Our new process produces 'plastic' from marine microorganisms that completely recycle into organic waste."
The researchers harnessed microorganisms that feed on seaweed to produce a bioplastic polymer called polyhydroxyalkanoate (PHA). "Our raw material was multicellular seaweed, cultivated in the sea," Dr. Golberg says. "These algae were eaten by single-celled microorganisms, which also grow in very salty water and produce a polymer that can be used to make bioplastic."

Fighting Pollution Without Using Fresh Water

"There are already factories that produce this type of bioplastic in commercial quantities, but they use plants that require agricultural land and fresh water. The process we propose will enable countries with a shortage of fresh water, such as Israel, China and India, to switch from petroleum-derived plastics to biodegradable plastics."

According to Dr. Golberg, the new study could revolutionize the world's efforts to clean the oceans, without affecting arable land and without using fresh water. 

"Plastic from fossil sources is one of the most polluting factors in the oceans," he says. "We have proved it is possible to produce bioplastic completely based on marine resources in a process that is friendly both to the environment and to its residents."

"We are now conducting basic research to find the best bacteria and algae that would be most suitable for producing polymers for bioplastics with different properties," he concludes.

The research was partially funded by the TAU-Triangle Regional R&D Center in Kfar Kara under the academic auspices of Tel Aviv University, and by the Israeli Ministry of Energy and Infrastructures.

Source: Tel Aviv University

Researchers Develop Plant-based 100% Biodegradable and Edible Food Packaging

University of Nottingham researchers have developed 100 percent biodegradable and edible food packaging made from plant carbohydrates and proteins to replace polluting plastic materials and improve storage, safety and shelf life.

Solution to Develop Advanced Materials for Packaging

 The Sino-UK project is led by Professor Saffa Riffat, from the Faculty of Engineering, whose research group is world-renown for innovations in sustainable materials, energy and building technologies. 

This includes their investigations into the structure and functionality of sustainable natural materials such as plant polysaccharides (carbohydrates) and proteins to develop advanced materials for applications in:

• Buildings
• Energy technologies
• Packaging 

Using a special technical approach, the team is working on plastic films derived from konjac flour and starch, cellulose or proteins that are fully edible and harmless if accidentally eaten by people or animals - unlike health issues associated with microplastics and other plastic waste that make their way into the food chain.

The researchers have found that plant carbohydrate and protein macromolecules bond together into a special network structure during the film-forming process. The network structure provides the film with a required mechanical strength and transparent appearance for the film to be used as packaging materials.

Degradable Solutions to Tackle Plastic Pollution

The project is jointly investigated by Marie Curie Research Fellow, Professor Fatang Jiang, an expert in biodegradable polysaccharide materials for moisture control, thermal insulation and infiltration. He recently joined the University of Nottingham from Hubei University of Technology in China, where part of the study is being worked on.

Prof Riffat, also a Fellow of the European Academy of Sciences and President of World Society of Sustainable Energy Technologies, said: “While plastic materials have been in use for around a century, their poor degradability is now known to cause serious environmental harm. This has led to more stringent recycling targets and even bans coming into force."

“Queen Elizabeth, for example, banned plastic straws and bottles from the royal estates in February 2018, and the EU plans to make all plastic packaging recyclable or reusable by 2030. We need to find degradable solutions to tackle plastic pollution, and this is what we are working on now.”

Plant-based Packaging: Edible, Degradable, Strong and Transparent

Fully-biodegradable bags could not only solve the safety and pollution issues of food packaging materials, but also efficiently lengthen the shelf life of fruit and vegetables and other fresh produce.

“In addition to being edible, degradable, strong and transparent, the packaging materials we are working on have low gas permeability, making them more air tight. This feature cuts moisture loss, which slows down spoilage, and seals in the flavor. This is of great importance for the quality, preservation, storage and safety of foods,” Professor Riffat adds.

The primary market for these plant-based packaging materials will be superstores and food supply chains. The research team is also aiming to advance the technology for general packaging in construction, express delivery and magazines, etc.

The project, currently supported by the £220K Horizon 2020 Marie Curie fellowship, will last two years with the potential to extend for another three to five years if further funding is secured.

Source: University of Nottingham

New Lightweight Bio-composite Using Date Palm Fiber Biomass for Automotive

A team of researchers have developed a bio-composite material using date palm fiber biomass. The new material can be used to produce sustainable, lightweight and low-cost applications in the automotive and marine industries. (non-structural parts, such as car bumpers and door linings).
The team involved researchers from:

• The University of Portsmouth 
• The University of Cambridge 
• INRA (Institut national de la recherche agronomique, a French public research institute dedicated to agricultural science) 
  

 University of Britanny, South Unlike synthetic composites reinforced by glass and carbon fibers, the date palm fiber polycaprolactone (PCL) bio-composite is completely:

• Biodegradable, 
• Renewable, 
• Sustainable and 
• Recyclable

Bio-Composite with Enhanced Mechanical Properties

In a study, published in the journal Industrial Crops and Products, the researchers tested the mechanical properties of the bio-composite. They found that the date palm fiber PCL had increased tensile strength and achieved better low-velocity impact resistance than traditional man-made composites.

Dr Hom Dhakal, who leads the Advanced Materials and Manufacturing (AMM) Research Group at the University of Portsmouth and co-author of the study, said:
“Investigating the suitability of date palm fibers waste biomass as reinforcement in lightweight composite materials provides a tremendous opportunity of utilizing this material to develop low-cost, sustainable and lightweight biocomposites. The impact of this work would be extremely significant because these lightweight alternatives could help reduce the weight of vehicles, contributing to less fuel consumption and fewer CO₂ emissions. The sustainable materials can be produced using less energy than glass and carbon fibers and are biodegradable, therefore easier to recycle.”

The study is one of the first to provide a comprehensive assessment of the improved mechanical properties of date palm fiber PCL bio-composites.

Waste Leaf Sheath Date Palm Fibers for Composite Reinforcement

Date palm fibers are one of the most available natural fibers in North Africa and the Middle East. Date palm trees produce a large quantity of agriculture waste, which is burned or land-filled, causing serious environmental pollution as well as the destruction of important soil micro-organisms. The part of the date palm tree which is often used as fibers is the sheath. The sheath is the part of the tree which surrounds the trunk of the plant. It is often torn lose when pruning the leaves.

“It’s a long journey,” said Dr Dhakal, “and we have to have patience and perseverance to make an impact. The challenge is getting consistent, reliable properties. It takes a long time to convince people to use a new class of materials, such as natural fiber reinforced composites for non-structural and structural applications.

“Meeting these challenges requires further research and innovation between academic institutions and industry.”

Dr Dhakal and his team have been working closely with industry to test the strength and viability of parts made from sustainable materials, such as date palm, flax, hemp and jute fibers. The AMM Research Group has been working in collaboration with researchers from institutions from around the world.

In the last 18 months, the group has published many high impact factor papers in journals including the Composites Science and Technology, Composites Part A and Composites Part B.

A recent collaborative study, published in the journal of Composite Part A: Applied Science and Manufacturing explored the potential of waste leaf sheath date palm fibers for composite reinforcement.


Source: University of Portsmouth

New Method to Prevent Clumping of BNNTs Using Common Surfactants

Boron nitride nanotubes sure do like to stick together. If they weren’t so useful, they could stay stuck and nobody would care. But because they are useful, Rice University chemists have determined that surfactants — the basic compounds in soap — offer the best and easiest way to keep boron nitride nanotubes (BNNTs) from clumping. That could lead to expanded use in protective shields, as thermal and mechanical reinforcement for composite materials and in biomedical applications like delivering drugs to cells.

BNNTs with “Super Cool Properties”

The research led by Rice chemist Angel Martí appears this month in the Royal Society of Chemistry journal Nanoscale Advances.
BNNTs are like their better-known cousins, carbon nanotubes, because both are hydrophobic – that is, they avoid water if at all possible. So in a solution, the nanotubes will seek each other out and stick together to minimize their exposure to water.
But unlike carbon nanotubes, which can be either metallic conductors or semiconducting, BNNTs are pure insulators: Current shall not pass.

“They have super cool properties,” said lead author Ashleigh Smith McWilliams, a Rice graduate student. “They’re thermally and chemically stable and they’re a great fit for a bunch of different applications, but they’re inert and difficult to disperse in any solvent or solution."

“That makes it really difficult to make macroscopic materials out of them, which is what we would eventually like to do,” she said.

Surfactants Separating BNNTs Effectively

Surfactants are amphiphilic molecules, with parts that are attracted to water and parts repelled by it. BNNTs are hydrophobic, so they attract the similar part of the surfactant molecule, which wraps around the nanotube. The surfactant’s other half is hydrophilic and keeps the wrapped nanotubes separated and dispersed in solution.

Of the range of surfactants they tried, cetyl trimethyl ammonium bromide (CTAB) was best at separating BNNTs from each other completely, while Pluronic F108 put the most nanotubes – about 10 percent of the bulk – into solution.

Once separated, they can be turned into films or fibers through processes like those developed by co-author Matteo Pasquali and his Rice lab, or mixed into composites to add strength without increasing conductivity, McWilliams said. The surfactant itself can be washed or burned off when no longer needed, she said.

A side benefit is that cationic surfactants like CTAB are particularly good at eliminating impurities like flakes of hexagonal boron-nitride (aka white graphene) from BNNTs. “That was a benefit we didn’t expect to see, but it will be useful for future applications,” McWilliams said.

Boron Nitride Nanotubes: The Great Building Block 

 “Boron nitride nanotubes are a great building block, but when you buy them, they come all clumped together,” Martí said. “You have to separate them before you can make something usable. This is what Ashleigh has achieved.”
He envisions not only ultrathin coaxial cables with carbon nanotube fibers like those from Pasquali’s lab surrounded by BNNT shells, but also capacitors of sandwiched carbon and BNNT films.

Enhanced Electronics with Insulating BNNTs

“We’ve had metallic and semiconducting carbon nanotubes for a long time, but insulating BNNTs have been like the missing link,” Martí said. “Now we can combine them to make some interesting electronics. It’s remarkable that a common surfactant found in everyday products like detergents and shampoo can also be used for advanced nanotechnology.”
Co-authors of the paper are Rice graduate student Carlos de los Reyes and undergraduate student Selin Ergülen; graduate student Lucy Liberman and Yeshayahu Talmon, professor emeritus of chemical engineering, at Technion – Israel Institute of Technology; and Pasquali, a Rice professor of chemical and biomolecular engineering, of materials science and nanoengineering and of chemistry. Martí is an associate professor of chemistry, of bioengineering and of materials science and nanoengineering.
The National Science Foundation, the Air Force Office of Scientific Research, the U.S.-Israel Binational Science Foundation and the Welch Foundation supported the research.
Source: Rice University

 

New Catalysis Concept to Obtain Polyester from Castor Oil

The development of future technologies that are not based on mineral oil and can be used for producing chemicals and plastics is one of the major tasks in modern materials science and a key challenge that needs to be addressed if sustainable industrial production is to have a future.

Synthetic Polyester from Plant Oil Feedstock

 A range of theoretical concepts and laboratory processes must be devised and tested to resolve challenges and problems arising in connection with the natural materials before potential applications for materials obtained from renewable resources can be probed.
One such concept has just been described by Professor Stefan Mecking in a current study on obtaining polyester from castor oil entitled “Synthetic Polyester from Plant Oil Feedstock by Functionalizing Polymerization” in the journal “Angewandte Chemie”.
With his colleague Dr Ye Liu, an Alexander von Humboldt Fellow and the first author of the study, Stefan Mecking presents a new way of obtaining polyester from fats and oils, more specifically, from castor oil. A well-known and chemically established building block that can be obtained from castor oil is Undecenol.
“Our idea was to interlink many of these molecules to form one large molecule, a plastic molecule. We wanted the whole process to be effective and readily accomplishable ‘in one go’”, Stefan Mecking elaborates.

Suitable Catalysts to Create Polyester Effectively

Undecenol has a group of alcohols at one end of the molecule and a double bond at the other. It was decisive to interlink these two groups to form an ester group in such a way as to enable simultaneous linkage with long-chain molecules, i.e. plastics. Such long-chain bonds are required to obtain the desired material properties. One of the major general challenges in regard to these procedures is to identify suitable catalysts.

“They are especially important because the reaction leading up to the formation of the desired long-chain molecules must be incredibly effective and proceed without any variance”, explains Stefan Mecking.

For the production of polyester as described in their study, the chemists used carbonylation to obtain the ester groups. “The problem is that Undecenol reacts with another smaller molecule, an aldehyde. If this happens, it does not become part of the molecule chain, which means that it gets lost”, says Stefan Mecking, summarizing the gist and great success of his research.

By using suitable catalysts, the researchers were able to prevent this loss and to create polyester effectively. While developing the catalysts, they also worked out the conceptual steps required for adjusting the melting point of the products. “Due to the insights we gained, we should be able to infer how to handle the melting points of other long-chain substrates”, concludes Stefan Mecking, alluding to potential transfer applications of his concept for other renewable resources that are even more readily available than castor oil.

Source: University of Konstanz

Graphene nanotubes make difference in the PVC plastisol industry

Graphene nanotubes are becoming a mainstream conductive additive. This technology is helping to create new business opportunities in various industries, including the PVC plastisol market. Successful market products with graphene nanotubes include ventilation ducting and fiberglass mesh for mining applications, anti-static textiles, and treadmill belts.

With their unique properties, graphene nanotubes push PVC plastisol performance higher, to fully satisfy market demand for 105 – 109 Ω/sq resistivity, to preserve a permanent and stable form even after harsh working conditions, to maintain abrasion resistance, and to demonstrate flexibility in the colouring of final products. This all is possible with just 0.25–2 wt.% of graphene nanotube concentrate, recently developed by OCSiAl.  

New technology is able to eliminate the common friction points in the usage of conventional anti-static additives, such as carbon black or ammonium compounds. Application of carbon black usually affects PVC plastisol’s mechanical performance very negatively, and turns final products black, whereas ammonium compounds can become unstable over time and provide only humidity-dependent resistivity. On the top of that, processing itself is complex – carbon black influences the rheology of material and facilitates dust formation on the surface. Graphene nanotubes, which can solve all these challenges, bring vast improvements to the PVC plastisol industry.

Nanotubes create new business opportunities for conductive PVC plastisol manufacturers. They enjoy an overwhelming welcome in the mining industry, where assurance of safety is vital. Here are a few examples of graphene nanotubes blazing their own trail in this market. 0.4–0.5 wt.%  graphene nanotube concentrate in PVC plastisol-based flexible ventilation ducting and fiberglass mesh for mining applications enable manufacturers to obtain a resistivity of 107 Ω/sq with maintained mechanical performance. PVC plastisol-based anti-static textiles and treadmill belts mapping out graphene nanotubes extensive application in industry. Uniform, permanent, stable and humidity-independent electrical conductivity – all guaranteed by graphene nanotubes.

Graphene nanotubes may have started as a “wonder-material,” but they are quickly becoming a conventional, economically viable technology for many industries. These tiny tubes are being used in a multitude of materials with increasing frequency, including PVC plastisol, polyurethane, epoxy, polyester, and acrylic polymers.   

 Source:OCSIAL

An eco-friendly vinyl hybrid resin made with zero styrene

Perma-Liner Industries, the manufacturer and supplier of trenchless pipeline rehabilitation equipment and materials in North America, is introducing a eco-friendly resin called Perma-Liner vinyl hybrid resin.

The newest resin in the company’s robust catalog is the only vinyl hybrid that was designed with zero styrene, extremely low VOC’s and is a hybrid vinyl ester with high-rigid polymer backbone.

“Our newest resin, the Vinyl Hybrid, has an array of benefits that are attractive to those looking for reduced labor costs, fast cure times and more,” said Rishi Vasudeva, business excellence manager at Perma-Liner. “This Resin is formulated with zero styrene – a potentially harmful substance per OSHA – allows it to be used in areas that would previously need to be evacuated due to the presence of styrene, such as schools, hospitals, churches, office buildings and more.”

The vinyl Hybrid resin has a standard pot life of more than eight hours and uses an easy initiator with one percent cumyl hydroperoxide (CHP) by weight making it cheap, easy and effective. With this new resin, it can be hot water or steam cured at a minimum of 140°F temperature held for 28 minutes with no post cure. The lower cure temperature of 140°F means it’s safer, gentler on equipment, a short time to maintain the temperature and easier temperature to reach for longer shots. Perma-Liner’s vinyl hybrid boasts consistent viscosity and is resistant to sag and draining around vertical surfaces and reinforcement.

Perma-Liner’s newest resin joins the company’s other resins: the high-performance vinyl ester, styrene-free silicate and the ever-popular 100 percent solids epoxy.

Source:perma-liner