Today's KNOWLEDGE Share: Is Graphene Safe?

Today's KNOWLEDGE Share

Is Graphene Safe?

 

Graphene is a nanomaterial that is made from pure carbon. It is often described as a two-dimensional (2D) material because it is only a few carbon atoms thick and therefore is almost entirely surface area.

Graphene can also be considered a “family” of materials because it comes in many forms and types including graphene oxide, reduced #grapheneoxide, graphene sheets, graphene flakes and other versions of this amazing material.

 

It is precisely because of the 2D characteristics and dimensions that make graphene one of the strongest and most electrically and thermally conductive materials ever measured. These attributes make it an extremely interesting material to use to make other materials better, lighter, stronger, more durable and more recyclable.

 

Because it is based on carbon, graphene can be used in an astonishingly wide scope of applications, from extremely sensitive sensors to high performance textiles, to much more efficient batteries, to advanced high strength composites and even to be used in concrete to reduce the amount of embedded CO2. #Graphenematerials are also being used and tested for use in biological and #medicalapplications from tissue engineering to #drugdeliverysystems. 

 

It is very important to remember that when graphene is used as a nano-additive in other products like #plastics, #textiles, #coatings or even concrete, it is typically used in very small quantities, often much less than just 1% by weight. Despite these small amounts, it contributes significant benefits to the materials it is added to. This also means the graphene is typically fully embedded into the host material it has been added to.

 

It is also important to note that nearly twenty years ago, the Royal Society published a landmark report that made it clear that nanomaterials that were embedded into any material matrix posed no more health and safety threat than any other materials.

 

Since the Royal Society report, #graphene , as a new nanomaterial, has faced inevitable questions that naturally arise over how to safely handle it, and if it poses any risks to #humanhealth. 

 

Any risk assessment for graphene, or any other material, has to be based on the formula: Hazard x Exposure = Risk. In this formula, you can see that a highly #hazardoussubstance like an acid may have restricted access, limiting its exposure and in so doing reducing its risk. When this formula is applied to the difference between engineered nanoparticles, such as graphene, and those found in the air because of air pollution, we can begin to put the risks into perspective.In addition, because graphene is both relatively new and there is confusion or misinformation about the health risks of nanomaterials in general, it is important to refer to scientific tests and studies that have thoroughly evaluated the risk profile of graphene materials for #dermal (skin) contact.

No nanomaterial in its raw form should be handled directly without the necessary precautions to prevent inhalation (safe handling settings and personal protective equipment for trained personnel). However, as the Royal Society report established nearly twenty years ago, once a nanomaterial (including graphene) has been incorporated into a product, it is virtually impossible to liberate the graphene particles from the host material.

 

This has been demonstrated conclusively in research commissioned by The Graphene Council and conducted by researchers at Virginia Tech (soon to be published by Nature/Springer) that showed once graphene had been embedded into protective gloves, it was impossible to separate the graphene from the gloves without completing destroying the gloves.

 

 

Source:Terrance Barkan

Blog : http://polymerguru.blogspot.com

 

Today's KNOWLEDGE Share:Toray developed Glass fiber reinforced PPS recycling technology

Today's KNOWLEDGE Share

Toray Developed Glass Fiber Reinforced PPS Recycling Technology

-Established New Technology which matches initial performance with virgin material and reduces CO2 emission -

Toray Industries, Inc., announced today that it has developed a technology that makes it possible to recycle glass fiber-reinforced #polyphenylenesulfide (PPS-GFRP) whose performance matches initial performance of virgin resins. By Increasing recycling ratio of PPS GFRP, it will contribute to reducing #CO2emission. 

PPS resin is an #engineering plastic with excellent #heatresistance and chemical resistance. More than 90% of PPS resin is glass fiber reinforced and applied for various types of industrial applications. Also, PPS resin has excellent insulation resistance. It is applied for #electronicparts such as #semiconductors and #EVparts. Demand of PPS resin is expected to increase along with these applications and the need of PPS recycling reins. 

The conventional process for recycling PPS-GFRP shortens #glassfibers and break them. This significantly decreases mechanical strength. To meet the performance requirements of resin molded products, manufacturers generally apply them in applications with lower quality requirements. This makes it difficult to increase the #recycling ratio of PPS resin.

Toray developed pellets for recycling materials by leveraging proprietary compounding technology to blend PPS resin with special #reinforcingfibers. Blending these pellets with recycled material makes it possible to maintain comparable performance with virgin material and can be applied to same application, such as horizontal recycling and expected to be used for various applications.

This technology can deliver comparable mechanical strength with injection grade moldings wholly made with virgin material. This is even when recycled material accounts for 50% or more of the #PPS-GFRP. Another benefit of 50% recycled content is that it reduces CO2 emission by at least 40%.

The company is working on technologies to broaden variations by designing different resins and additives in pellets for recycling materials. It looks to supply recycled PPS-GFRP pellets after engineering optimal pellet blend ratios and formulations that meet customer demand requirements and by drawing on Materials Informatics-based prediction technologies.

Collaborating with several molding companies and other business partners, Toray has already embarked on closed recycling initiatives with its technology. One move has been to supply customers with recycled PPS-GFRP pellets blended with those for materials recycling based on process remnants from customer plants. The company is also conducting tests to verify horizontal recycling and prepare for commercialization with cooperations from customers.

Source:Toray

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Evonik Launches Carbon-fiber Reinforced PEEK Filament for 3D Printed Medical Implants

Evonik is introducing a new #carbonfiber reinforced #PEEKfilament, for use in 3D printed medical implants.

This smart biomaterial can be processed in common extrusion-based 3D printing technologies such as #fusedfilamentfabrication (FFF). The specialty chemicals company will present the new product for the first time at coming next medical technology and #3Dprinting related trade shows.

High Bio-compatibility for Metal Allergy-patients:

Dubbed VESTAKEEP® iC4612 3DF and VESTAKEEP® iC4620 3DF, the two available filaments feature 12% and 20% carbon fiber content, respectively. The two grades offer a choice of material depending on the required strength and flex properties of 3D printed implants such as #bone plates and other reconstructive #prostheses.

Evonik’s VESTAKEEP® iC4612 3DF and VESTAKEEP® iC4620 3DF offer great benefits from the strength from the high carbon-fiber content, matched with the #ductility of its PEEK component. Additional product benefits include the ability to define the alignment of the carbon fibers during the 3D printing process, high bio-compatibility for metal allergy-patients, and the no x-rays artifacts.

“By introducing the world’s first carbon-fiber reinforced PEEK filament for long-term #medicalimplants, we continue to design biomaterials that open up new possibilities in today’s medical technology for patient-specific treatment,” says Marc Knebel, head of Medical Systems at #Evonik. “As passionate experts with decades of experience in polymer chemistry, we combine a unique set of competencies in materials science, manufacturing technologies and regulatory expertise to customers to accelerate time-to-market of new medical technologies for people's lives beyond limits.”

With a diameter of 1.75 mm, VESTAKEEP® iC4612 3DF and VESTAKEEP® iC4620 3DF are supplied on 500g and 1,000g spools that can be used directly in standard FFF/FDM 3D printers for PEEK materials. The filament is subjected to strict quality management for medical materials.

Grades for Short-term as well as Long-term Body Contact Applications:

Over the last five years, Evonik has been gradually developing new PEEK-based filaments for medical 3D printing applications and thus setting material quality standards in medical technology with #additivemanufacturing. The current portfolio includes different grades for long-term and short-term body contact applications:

Long-term body contact applications:

VESTAKEEP® i4 3DF – Implant grade (long-term)

VESTAKEEP® i4 3DF-T – Test and development grade

VESTAKEEP® iC4800 3DF – Osteoconductive implant grade

VESTAKEEP® iC4612 3DF – Carbon-fiber reinforced (12%) implant grade

VESTAKEEP® iC4620 3DF – Carbon-fiber reinforced (20%) implant grade

Short-term body contact applications:

VESTAKEEP® Care M40 3DF - Medical care grade

Source: Evonik/specialchem.com

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Perstorp Launches 100% Renewable 2-Ethylhexanol with Mass-balanced Carbon

#Perstorp launches 2-EH Pro 100, a new grade of #2Ethylhexanol (2-EH), now available with 100% renewable, traceable mass-balanced carbon content. When including the biogenic CO2 uptake absorbed by the renewable raw materials used, the product has a negative carbon footprint cradle to Perstorp gate.

Developed based on both physical and chemical traceability, 2-EH Pro 100 is designed to minimize the carbon footprint throughout the value chain, while supporting sustainable sourcing of renewable and recycled raw materials.

Enable Sustainable Transformation in Industry:

Offering a wide array of applications, 2-EH Pro 100 demonstrates the wide impact the #chemicalindustry has in so many areas of life. The launch of 2-EH Pro 100 is the newest in a series of additions of 100% renewable products based on traceable mass balance to Perstorp’s Pro-Environment portfolio including Evyron T100, Neeture N100, Valeric Acid Pro 100, and 2-EHA Pro 100.

“We have launched a number of grades of partially renewable products in the past years, but these new additions are especially exciting as they are some of the first 100% renewable sourced products of this type on the market.” Remarks Betty Lu, vice president of Business Unit Oxo and Plasticizers at Perstorp. “It showcases and further strengthens our commitment and continuous efforts to enable a sustainable transformation in the industry and value chain.”

2-EH Pro 100 is Perstorp's most recent step towards becoming Finite Material Neutral™, heralding a significant shift in the industry's dependence on virgin fossil raw materials while allowing downstream industries to reduce their Scope 3 emissions while also creating products with a reduced carbon footprint, without compromising on performance. 2-EH Pro 100 is an #ISCC PLUS (International Sustainability & Carbon Certification) certified product. Being ISCC PLUS certified means that all sustainable raw materials are ISCC PLUS or ISCC EU certified in all parts of the value chain all the way back to the point of origin.

“The 2-EH Pro 100 will enable our customers to use 2-EH based on 100% renewable traceable mass balanced #feedstock in their formulations,” says Magnus Hindsö, business manager for Oxo Products at #Perstorp. “This will provide a significant reduction of the product carbon footprint throughout the entire value chain and support the needed transition to more sustainable chemical solutions using less finite raw materials.”

Break Fossil Dependence and Incentivize Innovation:

Emphasizing transparency and traceability, the Traceable Mass Balance applies chemical and physical traceability. Applying both physical and chemical traceability means that it is possible to find the recycled/renewable molecules in the output product and enables brand owners to make credible product claims.

Source: Perstorp/specialchem.com

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Today's KNOWLEDGE Share:PU Memory Foam

Today's KNOWLEDGE Share:

In general, flexible PU foams that slowly return to their original state are called memory foam or LR (low resilience) foam.

To achieve this feature, the following should be considered.

1- Basic polyols: The correct choice of basic polyols is one of the most critical factors. At least two types of polyol should be used in this PU foam.

One of them should have a low OH value (20-30) and high Mw (6000-7000), and on the other hand, the second one should have a higher OH value (200-300) and lower Mw (500-800) to increase the recovery time. Also, you can use POP to adjust stiffness and flexibility.

2- Silicone/cell opener: PU memory foams have pneumatic properties. In order to create this feature, cell membranes do not have to be fully open, so air can flow in cells slowly.

3- Catalysts: as everyone knows, we need to balance gelling and blowing reactions in PU foams. In addition, air pressure should be controlled by catalysts.

4- Isocyanate: to synthesize PU memory foams, the isocyanate should be modified by 2 conventional base polyols like number 1.

5- Blowing agent: Water as a chemical blowing agent has an important role in viscoelastic properties. In this type of PU foam, water should not be high in the formula because the cells have not been large and fully open.

Source:Behzad Afrasan

Visit MY BLOG http://polymerguru.blogspot.com

#polymers #polyol #pufoams #blowingagent

Today's KNOWLEDGE Share:Carbon Fiber Chasis

 Today's KNOWLEDGE Share

A carbon fiber chassis for your dream build! 

Leading advanced engineering company Dash with its DNA derived from F1 technology has launched a ground-breaking new carbon monocoque chassis, the TR01! 

Delivering a step change in price to performance ratio, it will enable exciting projects in the growing performance automotive and motorsport industries as an affordable and versatile solution for hypercar, supercar, and motorsport projects.

Dash developed the TR01 chassis to fulfil an unaddressed market need for an affordable high-performance 'off-the-shelf' carbon fibre monocoque chassis. As a large, single carbon component, chassis manufacture is incredibly challenging – particularly when performance, quality, and consistency are concerned. Given the substantial growth of the hypercar market as well as motorsport demands for more affordable monocoques, the TR01 offers a compelling ‘off-the-shelf’ solution. 

The TR01 is suitable for any two-seat vehicle requiring a lightweight and stiff carbon monocoque and, although predominantly standardised, can be adapted to customer requirements. It offers a stiffness of 35,000Nm/Deg, weighs only 50 kilograms, and is priced under £30,000 – around 50% less than those currently available. 

Source:#Managingcomposites

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#composites #carbonfiber #autmotive #chasis #DASH