Today's KNOWLEDGE Share:modified PPE

Today's KNOWLEDGE Share

What are modified polyphenylene ethers?

Modified polyphenylene ether (modified PPE or m-PPE) is the common name for a family of polymer alloys formed by blending modified polyphenylene ether (PPE) resin a type of non-crystalline engineering plastic with various other resins. PPE resin is a non-crystalline resin with a glass transition temperature around Tg=210°C; the primary molecular chains in this resin consist of benzene rings linked by ether bonds, making the resin highly resistant to hydrolysis.

PPE resin exhibits low water absorption and boasts a low specific gravity of just 1.06, the smallest of all general-purpose engineering plastics. PPE resin also has the smallest linear-expansion coefficient of all general-purpose engineering plastics, ensuring excellent dimensional stability. Other advantages of PPE resin include its superior electrical properties, including excellent dielectric permittivity and loss tangent over a wide frequency range. PPE resin is further distinguished by its outstanding resistance to acids and alkalis.

On the other hand, drawbacks of pure PPE resin include high molten-state viscosity making it difficult to mold into desired shapes and susceptibility to degradation in the presence of aromatic hydrocarbon-based solvents such as oils.

Modified polyphenylene ether is also called modified polyphenylene oxide (modified PPO or m-PPO). However, PPO is a registered trademark, and the generic name is PPE.

PPE resin is rarely used in its pure form, but is frequently blended with polystyrene (PS) or other resins to yield a wide variety of alloy materials. Alloys of PPE and PS can achieve complete solubility for arbitrary values of the PPE/PS constituent ratio, and this fact can be exploited to improve fluidity and cover a wide range of heat-resistant behavior, making PPE/PS among the most important of all polymer-alloy systems. PPE resins are also easily blended with non-brominated, non-chlorinated flame retardants to yield flame-retardant materials.

Additionally, PPE may be alloyed with materials such as polyamide (PA), polypropylene (PP), polyphenylene sulfide (PPS), or elastomers such as SEBS to yield new materials combining the above-noted advantages of PPE resins with the features of the various partner resins.

The process of alloying PPE resin with other resins to improve material properties is known as modification, and the resulting materials are known as modified PPE (m-PPE) resins.

source:Asahi kasei

Today's KNOWLEDGE Share:Translucent composite tiles

Today's KNOWLEDGE Share

Translucent composite tiles for natural lighting and energy savings! 

More than reducing the electricity bill, companies can improve their work environment by including these GFRP tiles, which have high thermal resistance, on their buildings!

In addition to opaque composite roof tiles, Planefibra is adding translucent versions to its product offerings, highlighting their advantage in providing natural lighting to reduce electricity use, while blocking direct solar radiation to prevent overheating in buildings. According to the company’s website, the translucent tiles are made from glass fiber-reinforced polyester and have UV protection film on both sides.

“Natural lighting strengthens the sustainable profile of companies because consuming less, under any circumstances, preserves the environment. It is also an important ally in improving workplace conditions,” Cyrus Muchalski, general manager of Planefibra, says. 

Depending on the dimensions of the building, the season of the year and the incidence of sunlight, Muchalski calculates that companies are able to reduce their energy bill by up to 95% with lighting during business hours when using its composite tiles. “To obtain this result, the ideal is to cover 10% of the shed area with translucent tiles,” he notes.

With a minimum useful life of ten years, composite tiles have high thermal resistance. That is, even in places where the incidence of sunlight is high, there is said to be no risk of the roof deforming. Another advantage is the production of custom-made tiles, which adapt to the various existing roofing models. “Add to that the price, on average, 30% lower than polycarbonate tiles, the main competitor of those made of composites,” Muchalski compares.

Source: CompositesWorld/ #managingcomposites

Today's KNOWLEDGE Share:Loss of molecular weight

Today's KNOWLEDGE Share

It is correct that the degradation of plastic parts can lead to a decrease in their mechanical performance due to a loss of molecular weight.

However, the explanations provided in some posts I see on this platform may not always be entirely accurate.

The resistance to cavitation, which is the initiation of brittle failure, is controlled by the molecular weight between entanglements (Me) rather than the overall molecular weight (Mw). This means that cavitation will not be greatly affected by a loss of Mw as long as it remains well above Me (which is true in most commercial plastic grades except the very high flow grades).

However, many other mechanical properties, starting already from tensile strength, will sharply decrease as Mw decreases due to progressive disentanglement of the shorter polymer chains. This is especially confirmed by testing polymers at cryogenic temperatures where reputation and plasticity are suppressed.

The above explains why molecular weight does not influence the stress-strain response (measured in compression to avoid failure) while most tensile data will start collapsing with a decrease in Mw.

source:Vito leo

#plastics #molecularweight #entanglement

Today's KNOWLEDGE Share :Marie Curie, née Skłodowska-The Nobel prize in 1911

Today's KNOWLEDGE Share

Marie Curie, née Skłodowska-The Nobel prize in 1911

Marie Curie was a physicist and chemist who became the first woman to win a Nobel prize. Along with her husband Pierre, she discovered two elements: polonium and radium. She also carried out pioneering research into radioactivity.

Born Maria Skłodowska in Warsaw on 7 November 1867, Marie moved to Paris in 1891 to study physics, chemistry and maths at the University of Paris, where she earned two degrees, supporting herself through her studies by tutoring in the evenings. There she met Pierre Curie, who worked at the university, and they married in 1895. The couple set up a joint laboratory in a basement, building their own equipment for their experiments. At the time no one knew about the effects of radioactivity on the body, so they handled the elements they used in their research without any of the precautions or protective clothing we would use today. Marie even kept vials of what she was working on in her pockets or her desk drawers. More than 100 years after their discoveries, the couple’s notebooks are still so radioactive they have to be kept in lead-lined boxes and handled only while wearing protective clothing.

1898 was a busy year for the couple. Marie had been investigating the unusual properties of pitchblende, a black mineral that is rich in uranium. Two years earlier Henri Becquerel had discovered that uranium salts gave off rays that could penetrate objects in a similar way to the newly discovered X rays, but Marie had noticed that pitchblende gave off much more of what she later called radioactivity than would be expected if uranium alone was to blame.

Excited by Marie’s work, Pierre stopped his own research into crystals to help her grind down tonnes of the mineral in search of an answer. That July, the couple announced the discovery of the element polonium, which they named after Marie’s native Poland. But it still didn’t explain all of the radiation seen in pitchblende. Then, on 26 December, they announced the discovery of a second new element: radium. It took Marie another 12 years before she could isolate pure metal radium from pitchblende and definitively prove its existence.

The couple’s work on radioactivity won them a share of the Nobel prize in physics in 1903, alongside Becquerel, making Marie the first woman to win a Nobel prize. It almost didn’t happen – the Nobel committee wanted to honour only Pierre and Becquerel, but Pierre, alerted in advance, complained and Marie’s name was added. She also won the Nobel prize in chemistry, in 1911, for the discovery of radium and polonium, and the isolation of radium. With this she became the first person to win two Nobel prizes. She is still the only person to have won two Nobels in two different scientific fields.

source:New Scientist/Nobel Prize Organization

Stratasys to test 3D-printed material performance on moon

Stratasys Ltd., a leader in polymer 3D printing solutions, announced that it will provide 3D-printed materials for an upcoming lunar mission to test their performance on the surface of the moon. The experiments are part of Aegis Aerospace, Inc.’s first Space Science & Technology Evaluation Facility mission (SSTEF-1). SSTEF is a commercial space testing service, developed by Aegis Aerospace in Houston, Texas under NASA’s Tipping Point program, to provide R&D services on the lunar surface. The SSTEF-1 project focuses on technology development for space infrastructure and capabilities for the moon and near-earth space. The Stratasys experiments are sponsored by Northrop Grumman Corporation.

In this moon mission, Stratasys will provide 3D-printed samples that will be brought to the lunar surface by an unmanned lander in a carrier structure 3D-printed by Stratasys. Three materials will be the focus of two different experiments led by Northrop Grumman.

The first experiment assesses the performance of a sample coupon part made with Stratasys’ Antero® 800NA FDM® filament filled with tungsten. Antero 800NA is a high-performance PEKK-based thermoplastic with excellent mechanical properties, chemical resistance, and low outgassing characteristics. Adding tungsten is intended to provide shielding against harmful radiation such as gamma rays or x-rays.

The second passive experiment is designed to see how 3D-printed materials perform in space. It will include Antero 840CN03 FDM filament, which features ESD properties for use with electronics and was used on the Orion spacecraft. The experiment will also include a new ESD photopolymer manufactured by Stratasys partner Henkel for use with Stratasys’ Origin® One 3D printers and designed for high-heat environments. This experiment will subject coupon samples of the 3D-printed materials to moon dust, low pressure that can lead to outgassing, and the rapid temperature swings that result from virtually no atmosphere on the moon.

“Additive manufacturing is an important technology for space missions where every ounce of weight matters and high performance is essential,” said Chief Industrial Business Officer Rich Garrity. “This set of experiments will help us understand how to fully leverage 3D printing to keep people and equipment safe as we travel to the moon and beyond.”

Parts will be brought to the lunar surface by an unmanned lander in a Stratasys 3D printed carrier structure made from ULTEM™ 9085 thermoplastic, which is a material also commonly used in commercial aircraft interiors.

source:stratasys.com/jeccomposites.com

CARBIOS’ Enzymatic Solution for PLA Biodegradation Gets Food Contact Approval by FDA

CARBIOS announced that CARBIOS Active, its enzymatic solution for the biodegradation of PLA, is included in the U.S. FDA Inventory of Effective Food Contact Substances (FCS) with the assigned Food Contact Notification (FCN) 2325, effective since February 29, 2024.

With this milestone, CARBIOS Active can be used to make packaging materials that are sold in the United States. It can be used in food contact applications, including rigid and flexible packaging and other applications.

Produces PLA that is 100% Compostable at Room Temperature:

Integrated directly into plastic conversion processes, CARBIOS Active enables the creation of a new generation of PLA (polylactic acid). This PLA is 100% compostable, even at ambient temperature, without leaving toxic residues or microplastics. PLA made using this unique enzymatic solution is certified for industrial and home composting. CARBIOS Active was recently certified by the Biodegradable Products Institute (BPI), North America’s leading authority on compostable products and packaging. Food Contact Notification and BPI certification ensure the quality of CARBIOS Active. It provides brand owners and industrial composters with a reliable solution for designing and marketing fully biodegradable packaging, aligning with circularity commitments.

"For CARBIOS, product safety is a top priority and we consider FCN from the FDA as the gold standard. The US is a key market for CARBIOS’ biodegradation solution and we expect the FCN clearance to drive significant additional demand in North America in 2024. Well done to the teams from our biodegradation division for their relentless efforts," said Emmanuel Ladent, CEO of CARBIOS.

"CARBIOS is strategically forging commercial partnerships for its biodegradation solution with a specific focus on the US market. The consumer growing willingness to pay for green combined to increasing EPR regulations are putting pressure on brands and packaging industries to market more sustainable products, and CARBIOS Active answers their needs for improved circularity," said Stuart MacDonald, senior advisor for CARBIOS Biodegradation Division, North America.

Source: Carbios/omnexus.specialchem.com

Storage compartment demonstrates lightweight potential of sandwich construction

ENGEL Austria GmbH, ThermHex Waben GmbH, Edevis GmbH and the Fraunhofer Institute for Microstructure of Materials and Systems IMWS have produced a storage compartment flap for a truck interior in sandwich construction in a recently completed project. The flap, made from thermoplastic sandwich semi-finished products, demonstrates the enormous potential for saving weight with thermoplastic sandwich molding technology and its suitability both for molded components and for use in large-scale production.

The use of fibre composite materials and in particular the sandwich construction method offer particularly great potential for lightweight construction applications in commercial vehicles. Such sandwich structures consist of highly rigid and strong cover layers and a lightweight core. In addition to high material efficiency, this combination also enables very high weight-specific bending and buckling stiffness. The sandwich architecture is therefore also suitable for heavy-duty structural components, for example in aircraft and vehicle applications. It enables potential weight savings of up to 70 percent compared to monolithic structures, with a load-bearing capacity of the components that corresponds to or even exceeds that of (significantly heavier) metallic components.

One challenge to date has been that these components can hardly be manufactured in large-scale production processes. The use of thermoplastic fibre composite sandwich semi-finished products can be the solution here. These can be produced efficiently in continuous processes and turned into components in automated manufacturing processes. The participants in the joint “HyWaSand” project, which has now been successfully completed, have shown what is possible with this.

A flap for a storage compartment in a truck cabin was produced as a demonstrator. “We wanted to prove that the sandwich construction method with continuously produced thermoplastic sandwich semi-finished products is possible for such applications. Together with our partners, we succeeded,” says Dr. Ralf Schlimper, who led the project at the Fraunhofer IMWS.

The thermoplastic sandwich molding technology developed at the institute proved to be particularly valuable in achieving this goal. This is based on a new type of thermoforming process and was developed specifically for the fully automated production of continuous fiber-reinforced sandwich components with a thermoplastic matrix in large series. Thermoplastic sandwich semi-finished products, consisting of a thermoplastic honeycomb core and cover layers of fibre-reinforced thermoplastic UD tape laminates, are heated in an infrared oven and, after automated transfer to the molding tool, 3D thermoformed and functionalized by means of injection molding.

“The TS molding technology proved to be very efficient in our project. We were able to show that it enables the efficient production of 3D-molded and functionalized lightweight components in sandwich construction in the injection molding cycle, i.e. with cycle times of around one minute. This shows the potential for further fields of application, such as the car body sector,” says Schlimper.

In the project, ThermHex Waben GmbH focused primarily on the development of hybrid sandwich semi-finished products with a small cell width and functional polymer and metal foils to improve the surface quality. In addition, the new development of continuously manufactured semi-finished sandwich products with even lower material usage was driven forward. In conjunction with the necessary adaptation of the manufacturing process to make it suitable for series production, it was possible to achieve a further reduction in costs and weight compared to the previous standard configurations and non-recyclable material alternatives from reaction injection molding (RIM) processes. At the semi-finished product level, 30 to 45 percent of the weight can be saved with the same material thickness or up to 22 percent of the weight with comparable mechanical performance and greater material thickness. This improved resource efficiency in the use of materials also has a proportionally positive effect on material costs and CO2 emissions.

In test structures, the project was able to demonstrate that components with Class A surfaces, which are particularly important for the automotive industry, can also be manufactured from thermoplastic semi-finished products in sandwich construction. Progress was also made for metal-plastic hybrid sandwich materials as part of the “HyWaSand” project, for example the lamination of test structures with metallic cover layers within the TS molding process.

“There are still open research questions here that we want to continue working on. This makes it all the more valuable that we have made great progress in the project in providing virtual engineering methods for process and component development and have also developed feasible test tools for various common component design features. The new possibilities for inline inspection and for suitable non-destructive testing methods to ensure component quality also enable us to rapidly bring the technology even closer to application in various cost- and weight-sensitive areas,” says Schlimper.

“We are currently investigating the transferability of the results to customer development projects in order to facilitate entry into new market segments,” says Matthias Biegerl, who led the project at ElringKlinger. “The potential is huge. By manufacturing the components in large series, cost-efficient lightweight structures for interior and body components can be produced.”

The demonstration at JEC World 2024 has already generated a lot of interest. The project partners will also present the component and the technology at the Composite Sandwich Conference on April 24-25, 2024 in Halle (Saale).

source:www.thermhex.com/www.jeccomposites.com