Healing Halogens

 Healing Halogens #medicine

A significant number of drugs are halogenated.

Typically, insertion of halogen atoms on hit or lead compounds is performed to occupy the binding site of molecular targets in order to improve the drug−target binding affinity and/or reduce metabolism. 14 out of the 50 molecules approved by the FDA in 2021 contain halogens.

The introduction of F onto a chemical scaffold is able to infer changes that affect the physicochemical properties and the conformation of a molecule. Being the most electronegative element in the periodic table, F plays an important role in the modulation of pKa of neighboring functionalities. Substituting F for H on aromatic groups is also well known to improve metabolic stability.

Lipophilicity is also affected by the addition of F onto aliphatic and aromatic scaffolds. The monofluorination or trifluoromethylation of saturated alkyl groups usually decreases the lipophilicity due to the strong electron-withdrawing capabilities of fluorine. F-arenes are more lipophilic than des-F ones due to the low polarizability of the C-F bond. The installation of a fluorine atom in the ortho-position to an NH function on the aromatic ring is often used to enhance membrane permeability.

From a conformational perspective, the addition of one single F has a reduced steric effect, leaving mostly unchanged the interaction with the receptor site if compared to the same interaction with a molecule bearing an H atom in the same position. This can be explained by the similar van der Waals radii of F and H: 1.47 Å and 1.20 Å, respectively.

The commonly used trifluoromethyl group is sterically more demanding and almost equivalent to an ethyl group. The highly electronegative nature of fluorine makes it a hydrogen bond acceptor from HBD but does not establish as good of halogen bonds as Cl and Br, because it does not typically feature a σ-hole. Another important use is that fluorinated functionality can be incorporated into endogenous substrates or ligands through 19F-markers to investigate protein functions.

Cl is greater in size than F, and the C–Cl bond is stable enough that it allows its insertion in diverse heterocyclics. Cl is a better halogen bond acceptor compared to F. The most important impact of a nonreactive Cl atom on the biological activity of many compounds comes when it is a substituent on an aromatic, heteroaromatic or olefinic moiety. In these cases, the steric and/or electronic effects of the chlorine substituents lead to local electronic attraction or repulsion and/or to steric interference with any surrounding amino acids of target proteins. The Cl atom is often viewed as isosteric and has similar physicochemical properties to the methyl group; therefore, it is very often selected as a bioisosteric replacement because of its ability to alter the in vivo metabolism.

>250 FDA-approved chlorine-containing drugs are available on the market (as of 2019). 

Leonardo, Vertical Aerospace to jointly develop VX4 eVTOL carbon fiber fuselage!

 📢Spreading the Word!📢 Leonardo, Vertical Aerospace to jointly develop VX4 eVTOL carbon fiber fuselage!

"Vertical Aerospace an aerospace and technology company pioneering zero-emissions aviation has agreed to a joint development program with Leonardo for the design, testing, manufacture, and supply of the carbon fiber composite fuselage for Vertical’s VX4 electric aircraft."

"The VX4 is a near-silent, entirely electric, piloted aircraft that is expected to have a range of more than 100 miles and to reach top speeds of up to 200 miles per hour. With a four-passenger capacity, Vertical says the zero-operating emissions VX4 will also have a low cost-per-passenger mile, similar to that of a taxi."

"Vertical and Leonardo will work together on optimizing lightweight composite structures, modular design, systems installation, and structural testing for the co-development of the aircraft’s fuselage. According to Vertical, this is currently in place for at least six certification aircraft, up to the successful certification of the VX4."

Source:#managingcomposites

Evonik Develops Osteoconductive PEEK Filament for Improved Bone and Implant Fusion

Evonik is further expanding its portfolio of 3D-printable biomaterials for medical technology: The specialty chemicals company has developed VESTAKEEP® iC4800 3DF, a new osteoconductive PEEK filament that improves fusion between bone and implants.

The high-performance polymer can be processed in common extrusion-based 3D printing technologies such as fused filament fabrication (FFF). Evonik will present the new product for the first time at the AAOS trade show in Chicago, USA (March 22-26, 2022).

Excellent Biocompatibility and Biostability

The new PEEK filament is a biomaterial from Evonik's VESTAKEEP® Fusion product line launched in 2020. The high-performance polymer impresses with excellent biocompatibility and biostability as well as improved osteoconductive properties. The osteoconductivity was achieved by using a functional special additive - biphasic calcium phosphate (BCP). The BCP additive allows bone cells to adhere to implants more quickly, thus positively influencing the boundary, so-called osteointegration, between the bone and the implant. This, in turn, will accelerate bone fusion and thus patient recovery.

VESTAKEEP® iC4800 3DF was developed for use in the Fused Filament Fabrication (FFF) technology. With a diameter of 1.75 mm, the PEEK filament in natural color is wound onto 250 gram or 500-gram spools. They can be used directly in standard FFF 3D printers for PEEK materials. Tests on various 3D printers as well as customer feedback confirm the excellent processability of Evonik’s new filament.

Manufactured Under Strict Quality Management

Furthermore, VESTAKEEP® iC4800 3DF has been specially designed so that the functional additives are available directly on the surface of the 3D printed implant without further post-processing steps - a novelty for osteointegrative PEEK biomaterials. Like all products of the Fusion range, VESTAKEEP® iC4800 is manufactured under strict quality management for biomaterials.

"No other application field showcases more the classic advantages of 3D printing, such as individualization or design freedom, than medical technology," says Marc Knebel, Head of Medical Systems at Evonik. "Since the product launch of the first PEEK filament a good three years ago, we have been expanding the possibilities of modern medical technology in the individual treatment of patients using additive manufacturing by constantly developing new innovative biomaterials."

Source:EVONIK

A carbon fiber electric skateboard

 📣Composites Showcase!📣

A carbon fiber electric skateboard?

Conventional skateboards usually consist of a relatively flat wooden board where the rider stands, also known as the deck. Underneath the deck for electric skateboards is a plastic box containing equipment, including the battery. EMI's design, however, features a trough-shaped deck. With the exception of the motors, which are mounted on the back of the skateboard, this houses all the electric and electronic functions, including the battery. The trough is enclosed by a cover. Using @Lanxess' Tepex, EMI is able to manufacture the trough-shaped part with a wall thickness of just three millimeters, and despite the thin walls, the electric and electronic components in the deck are said to be safely protected against impact as well as moisture.

The result is a very light structure: the Okmos SL-01 deck weighs just 2.5 kilograms!

According to the manufacturer, the trough-shaped composite part is manufactured in a single hybrid molding process step. A robot inserts the metal base plate used to attach the truck axles into an injection molding tool. Then, a heated and plasticized Tepex section is placed within the tool. In one operation, the section is formed and the entire structure overmolded with a short glass-fiber-reinforced plastic compound. 🕵🏻‍♀️

The composite section is made from polyamide-6 (PA6)-based Tepex dynalite 102-RG600(6), which is reinforced with six layers of continuous glass fiber rovings. The deck cover is also made from this material. Lanxess’ PA6 Durethan BKV30H2.0EF is used for overmolding. Containing 30% short glass fibers by weight, the compound melt flows easily, making it suitable for this type of application.

Source: CompositesWorld

TheNativLab

Scientists Develop Cellulose Nanocrystals-based Composite with Bone-hard Toughness

 An MIT team has engineered a composite made mostly from cellulose nanocrystals mixed with a bit of synthetic polymer. The organic crystals take up about 60 to 90 percent of the material — the highest fraction of CNCs achieved in a composite to date.

The researchers found the cellulose-based composite is stronger and tougher than some types of bone, and harder than typical aluminum alloys. The material has a brick-and-mortar microstructure that resembles nacre, the hard inner shell lining of some molluscs.

The Recipe for CNC-based Composite

The team hit on a recipe for the CNC-based composite that they could fabricate using both 3D printing and conventional casting. They printed and cast the composite into penny-sized pieces of film that they used to test the material’s strength and hardness. They also machined the composite into the shape of a tooth to show that the material might one day be used to make cellulose-based dental implants — and for that matter, any plastic products — that are stronger, tougher, and more sustainable.

“By creating composites with CNCs at high loading, we can give polymer-based materials mechanical properties they never had before,” says A. John Hart, professor of mechanical engineering. “If we can replace some petroleum-based plastic with naturally-derived cellulose, that’s arguably better for the planet as well.”

Hart and his colleagues looked to develop a composite with a high fraction of CNCs, that they could shape into strong, durable forms. They started by mixing a solution of synthetic polymer with commercially available CNC powder. The team determined the ratio of CNC and polymer that would turn the solution into a gel, with a consistency that could either be fed through the nozzle of a 3-D printer or poured into a mold to be cast. They used an ultrasonic probe to break up any clumps of cellulose in the gel, making it more likely for the dispersed cellulose to form strong bonds with polymer molecules.

They fed some of the gel through a 3-D printer and poured the rest into a mold to be cast. They then let the printed samples dry. In the process, the material shrank, leaving behind a solid composite composed mainly of cellulose nanocrystals.

“We basically deconstructed wood, and reconstructed it,” Rao says. “We took the best components of wood, which is cellulose nanocrystals, and reconstructed them to achieve a new composite material.”

Nacre-like Architecture Resists Cracks

Interestingly, when the team examined the composite’s structure under a microscope, they observed that grains of cellulose settled into a brick-and-mortar pattern, similar to the architecture of nacre. In nacre, this zig-zagging microstructure stops a crack from running straight through the material. The researchers found this to also be the case with their new cellulose composite.

They tested the material’s resistance to cracks, using tools to initiate first nano- and then micro-scale cracks. They found that, across multiple scales, the composite’s arrangement of cellulose grains prevented the cracks from splitting the material. This resistance to plastic deformation gives the composite a hardness and stiffness at the boundary between conventional plastics and metals.

Going forward, the team is looking for ways to minimize the shrinkage of gels as they dry. While shrinkage isn’t much of a problem when printing small objects, anything bigger could buckle or crack as the composite dries.

“If you could avoid shrinkage, you could keep scaling up, maybe to the meter scale,” Rao says. “Then, if we were to dream big, we could replace a significant fraction of plastics, with cellulose composites.”

Source: MIT

LM Wind Power reports it will produce zero waste blades by 2030!

 📢Spreading the Word!📢 L

M Wind Power reports it will produce zero waste blades by 2030!

"LM Wind Power announced its pledge to produce zero waste blades by 2030 in order to reduce the carbon footprint of the company’s products. The commitment represents a step forward in the company’s sustainability journey after becoming what it says was the first carbon-neutral business in the wind industry back in 2018."

"LM Wind Power will play a central role in supporting its customers to develop fully circular wind turbines that generate less waste during their production. In practice, LM Wind Power’s vision of zero waste blades means the company aims to send no manufacturing materials and packaging to landfill and incineration without energy recovery by 2030."

"Waste from manufacturing represents one of the biggest challenges faced by many industries as they seek to reduce their carbon footprint. Nearly one-third of its operational carbon footprint comes from waste disposal. Moreover, in the wind industry, around 20-25% of the materials purchased by wind turbine blade manufacturers do not go into the final product, and research indicates that blade manufacturing waste volumes are expected to be larger than decommissioned blade volumes during the coming decade."

"For wind turbine and blade manufacturers alike, LM Wind Power says, the key to reducing the product carbon footprint lies in the supply chain. In the blade life cycle, around 75% of CO2 emissions occur in the supply chain."

Source :managingcomposites

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Pitch based carbon fiber

 We have developed PotenCia™, pitch-based fine #carbonfiber, which can be applied as additives for the #LiB system. When used in the LiB system, it shows higher performance and can improve the durability of #battery with low concentration.

Find out more: https://lnkd.in/gtsW8ZSu

We, Teijin Group, are working tirelessly to refine our #automotive technologies and solutions for reduced CO2 emissions without compromising high performance.

Source:Teijin

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