polymerguru

  Today's KNOWLEDGE Share: Fourier transform infrared spectroscopy (FTIR) is a fundamental tool for the qualitative compositional analysis of polymeric materials. It allows the user to identify the material being tested. In order to properly interpret the results of FTIR, the key considerations regarding spectral band formation must be understood.    FTIR bombards with infrared energy, and certain frequencies are absorbed by the sample and others transmitted. The frequencies at which the material absorbs infrared energy correspond to molecular vibrations that are produced within the sample. The infrared spectrum representing a material consists of absorption bands associated with discrete functional groups, the building blocks that make up the molecule. The frequency at which a functional group absorbs is based on a number of factors:   Atomic weight of the bonded species: Frequency decreases (lower cm-1) with increasing atomic weight.   Bond energy: Freque...

Why does carbon fibers possess such a high modulus in the direction of the fiber? As many questions related to materials engineering, to answer that we have to understand the unit cell structure of the material, in this case, graphite. The crystal structure of graphite, consists of sp2 hybridized carbon atoms arranged two-dimensionally in a honeycomb structure in the x-y plane. The layers, termed graphene layers, are stacked parallel to each other in a 3D structure. The most common stacking sequence of the layer planes is the hexagonal form with an ABABAB packing sequence. This way, some atoms (α) have neighbors directly above and below in adjacent planes, while others (β) don’t. The bonding between the layers is van der Waals bonding, so the carbon layers can easily slide with respect to one another. Due to the difference between the in-plane and out-of-plane bonding, graphite has a high modulus of elasticity parallel to the plane and a low modulus perpendicular to the plane. Thus, gr...

Today's KNOWLEDGE Share: FIRST APPLICATION OF CARBON FIBERS Carbon fibers are older than you imagine! The first carbon fibers date back to 1860! In 1879, a certain guy named Thomas Edison chose carbon fibers to manufacture light bulb filaments. At that time, they were not petroleum-based. Instead, they were produced through the pyrolysis of cotton or bamboo filaments. These filaments were ''baked'' at high temperatures to cause carbonization to take place. But why were they chosen? The answer is pretty straightforward and has nothing to do with high strength! At the time, Edison noticed that their high heat tolerance made them ideal electrical conductors. However, soon later tungsten took over as the light bulb filament of choice in the early 1900s, and carbon fiber became obsolete for the next 50 years or so. During the 1960s, a Japanese researcher named Akio Shindo, manage to manufacture carbon fibers using PAN as a precursor. This way, his team was able to achiev...

  The order comprises 40 Airbus A350s, 20 Boeing 787s and 10 Boeing 777-9s widebody aircraft, as well as 210 Airbus A320/321 Neos and 190 Boeing 737 MAX single-aisle aircraft. The A350 aircraft will be powered by Rolls-Royce engines, and the B777/787s by engines from GE Aerospace. All single-aisle aircraft will be powered by engines from CFM International. Commenting on the occasion, Tata Sons and Air India Chairman, Mr N Chandrasekaran, said: “Air India is on a large transformation journey across safety, customer service, technology, engineering, network and human resources. Modern, efficient fleet is a fundamental component of this transformation. This order is an important step in realising Air India’s ambition, articulated in its Vihaan.AI transformation program, to offer a world class proposition serving global travellers with an Indian heart. These new aircraft will modernise the Airline’s fleet and onboard product, and dramatically expand its global netwo...

  Today's KNOWLEDGE Share: Dry-jet wet spinning process to produce aramid fibers Aramid fiber is a generic term for a class of synthetic organic fibers called aromatic polyamide fibers. The U.S. Federal Trade Commission gives a good definition of an aramid fiber as “a manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in which at least 85% of the amide linkages are attached directly to two aromatic rings.” Well-known commercial names of aramid fibers include Kevlar and Nomex (DuPont) and Twaron (Teijin Aramid). The basic chemical structure of aramid fibers consists of oriented para-substituted aromatic units, which makes them rigid rod-like polymers. The rigid rod like structure results in a high glass transition temperature and poor solubility, which makes the fabrication of these polymers, by conventional drawing techniques, difficult. Instead, they are spun from liquid crystalline polymer solutions by dry-jet wet spinning. The dry-jet wet...

  Today's Knowledge Share: HYDROGELS: Hydrogels are one of the hottest topics in bioelectronics. Conductive hydrogels, in particular, might prove crucial for treating nerve injuries.Hydrogels are networks of polymers that hold a large amount of water - like a jelly. By inserting polyacrylamide and polyaniline, researchers in China were able to create hydrogels that conduct electricity. They demonstrated that this new material could treat nerve injuries by forming a conducting biocompatible link between broken nerves. Peripheral nerve injury – for example, when a peripheral nerve has been completely severed in an accident – can result in chronic pain, neurological disorders, paralysis, and even disability.They are traditionally very difficult to treat. The new hydrogel could change this. The team implanted the hydrogel into rats with sciatic nerve injuries. The rats’ nerves recovered their bioelectrical properties – as measured by electromyography one to eight weeks following the op...

  In recent years, environmental problems caused by global warming have become more apparent due to greenhouse gases such as CO2. In natural photosynthesis, CO2 is not reduced directly, but is bound to organic compounds which are converted to glucose or starch. Mimicking this, artificial photosynthesis could reduce CO2 by combining it into organic compounds to be used as raw materials, which can be converted into durable forms such as plastic. Fumaric Acid from CO2 A research team led by Professor Yutaka Amao from the Research Center for Artificial Photosynthesis and graduate student Mika Takeuchi, from the Osaka Metropolitan University Graduate School of Science, have succeeded in synthesizing fumaric acid from CO2, a raw material for plastics, powered—for the first time—by sunlight. Their findings were published in Sustainable Energy & Fuels. Fumaric acid is typically synthesized from petroleum, to be used as a raw material for making biodegradable plastics such as ...