Today's KNOWLEDGE Share:Petrochemicals Historical Timeline 4

Today's KNOWLEDGE Share:

Petrochemicals Historical Timeline 4

1930s New process of alkanisation and fine powder fluid-bed production increases the octane rating of aviation gasoline.

1931 Neoprene invented by DuPont scientists after attending a lecture by Belgian priest and chemistry professor Dr Julius Nieuwland.

1931 German organic chemist Friedrich Bergius and Carl Bosch share a Nobel Prize for their work in high-pressure hydrogenation.

1933 German scientists invent Buna-S, a synthetic rubber made from styrene and butadiene.Mainly used for car tyres.

1933-1935 Plexiglass was discovered by accident by German researcher Otto Röhm. He developed a method for polymerising methyl methacrylate

which was intended for use as a drying oil in varnishes but found it could also be used as a coating for safety glass. Plexiglass was manufactured from 1938, used in war planes from 1940 and in car exteriors from 1974.

1933 A white, waxy material, is discovered by accident by two organic chemists at the UK’s Imperial Chemical Industries (ICI) research laboratory. ICI chemist Michael Perrin developed a high-pressure synthesis process in 1935 to turn the waxy material into polyethylene. It was available on the mass market in the toy sector from the 1950s.

1935 American chemist Wallace Hume Caothers created a fibre which came to be known as Nylon.Nylon stockings were introduced to the US market in 1940 to great acclaim. The material is used today for multiple purposes including fabrics, carpets, ropes and guitar strings. Solid nylon is used for mechanical parts.

1936 Catalytic cracking, using silica and alumina-based catalysts, introduced by French scientist Eugene Houdry

(to be continued)

Source:WPC Guide

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#petrochemicals #nylon #plastics #polymerscience #neoprene  #butadiene #polyethylene  #development #alumina #mma #bosch

Japanese Researchers Develop Nanoparticle-based Latex Films

A team of researchers from Japan, led by associate professor Daisuke Suzuki from Shinshu University, develop an innovative way to produce tough and crack-resistant elastic nanoparticle-based latex films without using harmful organic solvents and fillers additives.

It is a new class of latex films composed of rotaxane-crosslinked acrylic nanoparticles. These films exhibit remarkable mechanical properties, including excellent crack-propagation resistance without any additives and are easily recyclable, paving the way for more environmentally friendly materials.

Interlocking Mechanism in Rotaxane

Synthetic latex films, a type of nanoparticle-based films, are widely used across many fields, but they usually contain harmful additives, which are also expensive, to enhance their strength. It is essential to ensure that they are safe, durable and sustainable. This is especially true for synthetic latex films, which are widely used in packaging, biomedicine and electronics.

The key to the approach of the researchers was a novel molecular structure known as rotaxane, which comprises two main components, a ring-like molecule and a linear axle molecule. The ring-like molecule is threaded through the axle molecule, which becomes mechanically trapped thereafter owing to the shape of the axle terminations.

The researchers leveraged this interlocking mechanism in rotaxane by making the ring-like molecule chemically bind to one polymer chain and the axle molecule to another chain. Next, they prepared mixtures of water and polymer nanoparticles through standard ultrasonication and subsequent polymerization that, in turn, were used to produce latex films.

The stretching experiments performed on these films revealed that the rotaxane-based strategy resulted in some remarkable properties.

“In contrast to conventional nanoparticle-based elastic polymers, the latex films composed of the rotaxane-crosslinked nanoparticles exhibited unusual crack propagation behavior,” explained Dr. Suzuki. “The direction of crack propagation changed from being parallel to the crack to one perpendicular to the crack, resulting in an increased tear resistance.”

Suitable for Developing Additive-free Polymer Films:

The new approach to making latex films offers many advantages over conventional methods. Most importantly, no toxic additives are needed to achieve reasonable film toughness. Moreover, since only a tiny amount of rotaxane is needed, the total weight of the films can be kept low while preserving flexibility. The proposed latex films are sustainable as well.

“They are degradable and can be easily disassembled into individual nanoparticles by simply soaking them in an environmentally friendly organic solvent, such as an aqueous ethanol solution,” highlighted Dr. Suzuki.

Source: Shinshu University/specialchem

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#nanoparticles #films #elastic #polymers #latexfilms

Today's KNOWLEDGE Share: Maximum shear

Today's KNOWLEDGE Share:

Why is the maximum shear recorded somewhat inside the skin of molded parts ?

Fountain flow brings the material on the walls "sideways". So, the very top skin of a molded specimen is not very oriented at all. Inside the frozen skin (a time/position dependent "moving boundary" line) we get maximum shear and corresponding higher molecular orientation.

The "yellow layer" depicted can often be responsible for delaminations of molded parts, since high shear could expel low molecular fractions or lubricants which accumulate under the first formed skin.

Low viscosity fractions will naturally move (hydrodynamic forces) to the highest shear-stress regions to minimize total flow energy.

Extreme levels of orientation also freeze the material in a lower entanglement state, which can somewhat compromise the interlayer integrity in the thickness direction while boosting in-flow performance.

Source:Vito Leo

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#polymers #plasticsindustry #injectionmolding #shear #materialsscience #freeze #friction #flow

Solar energy demand could rise by 40% in 2023 says Bloomberg Intelligence

#Solar will remain the energy sector’s fastest-growing sub-segment, says a Bloomberg Intelligence report, which suggests that demand could soar by 30-40% in 2023. 

The good news for the solar sector follows a record 2022, when global solar capacity expanded by about 38%. 

Electronics distributor Avnet Abacus recently published data showing that the number of UK solar companies listed on Crunchbase continues to grow year-on-year and in 2022 total investment in the sector was $362 million (around £286 million), with a mean average funding round of $40.2 million (£32 million). 

The Bloomberg report added that profitability metrics for solar companies could also improve with cheaper lower input costs and supply chain constraints.  

Rob Barnett, BI Senior #cleanenergy Energy Analyst, said: “Global solar demand may rise about 30-40% in 2023 with industry revenues increasing about 35%. Despite such fast top-line growth, solar share prices have trailed this year relative to the overall market, though we note that solar shares are performing broadly in line with the energy sector.” 

“We believe the rapid pace of #growth can be sustained in 2023-25, which may boost sentiment and help lift consensus sales expectations in the years ahead,” Barnett added. 

"Rapid solar growth, easing supply-chain disruptions and a potential reversal in commodity prices could help boost Ebitda for most solar-exposed companies in the years ahead,” Bloomberg said in a statement. 

The UK currently lacks investment incetives for renewables to match the US's  Inflation Reduction Act (IRA) and there are concerns that new solar projects are being delayed by planning rules, grid capacity and lack of clarity on future government policy. This week, however, saw the granting of planning permission to a solar farm which is projected to be the UK’s largest in Essex. 

#Bloomberg notes that the price of polysilicon – a key input for the #solarindustry – has fallen nearly 60% since December 2022, which could increase the revenues of module manufacturers, and would eventually feed through to lower costs for other companies. 

Source:solarpowerportal.co.uk

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Today's KNOWLEDGE Share: UNDERSTANDING THE DIFFERENCE BETWEEN SBS & SEBS THERMOPLASTIC ELASTOMERS

Today's KNOWLEDGE Share:

UNDERSTANDING THE DIFFERENCE BETWEEN SBS & SEBS THERMOPLASTIC ELASTOMERS?

Over half a century ago, as I watched a fellow research student produce fascinating colours in his reaction vessel, as he prepared block copolymers using anionic polymerisation, little did I realise I was witnessing the dawn of a new class of materials —thermoplastic elastomers (TPE).

Using this system it was possible to construct precise polymer chains, with a sequence of styrene repeat units, tagged onto a sequence of butadiene repeat units and finished off with another block of styrene units. This gave a styrene-butadiene-styrene block copolymer (SBS).

It was soon discovered that, at ambient temperatures (below the glass transition temperature of polystyrene) the styrene block tails aggregate in clusters (domains) to act as rigid physical crosslinks. This maximises the high elastic properties of the butadiene block. At elevated temperatures the styrene domains disentangle and the polymer becomes a thermoplastic melt, suitable for extrusion and injection moulding.The elastic extension and recovery properties of SBS match those of conventional vulcanised elastomers. However, the advantage is that there is no ‘cure’ stage and process time and energy consumption are greatly reduced. Also SBS can be processed from solution.

The soft touch characteristics of SBS were soon exploited by designers, particularly in hand tools. Applications now stretch to toys, automotive trim, tubing, wire & cable, footwear and to adhesives, sealants and even bitumen additives.

However SBS has degradation issues at high temperatures and the butadiene content makes it prone to oxidation and weathering, without appropriate antioxidants. By converting the butadiene block to ethylene-butylene repeat units, SEBS thermoplastic elastomers have better thermal stability and better weathering resistance, without sacrificing too much in mechanical performance. SEBS is also steam sterilisable.

Trade Names:

SBS:  Kraton D, Evoprene, Dryflex, Solprene, Europrene SOL T, K-Resin

SEBS:  Kraton G, Evoprene G, Dryflex, Thermolast K, Europrene SOL TH

Source:Dr.Charlie Geddes from Hardiepolymers

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#sebs #elastomers #tpe #polymerisation #kraton #butadiene #styrene #adhesives #toys #cables #thermalengineering

Fraunhofer IPT have developed a novel recycling process for used H2 tanks

Unwinding in high quality: Continuously detached and recycled thermoplastic carbon fibre tapes with a new recycling approach.

The sales market for plastic products is growing. At the same time, however, the environmental impact of non-degradable plastics is increasing and requires new recycling strategies. At the Fraunhofer Institute for Production Technology IPT in Aachen, researchers have developed a novel recycling process to recover the fibre composite material of used pressure tanks in a peeling process and reuse it for new lightweight products. The aim is to recycle fibre-reinforced plastics (FRP) without any significant loss of product quality. The Fraunhofer team has now succeeded in doing so in the “Tankcycling” research project: Over 90 percent of the mechanical strength properties are retained in the recycled material.

Fibre-reinforced pressure tanks – light and stable

Since hydrogen is regarded as the energy storage medium of the future and since this odorless gas has to be stored under high pressure, its use in trucks or automobiles inevitably entails the question how to store it safely. This is achieved when hydrogen is stored in high-quality pressure vessels made of carbon fibre-reinforced plastics. These pressure vessels must be highly resilient and at the same time lightweight and corrosion-resistant so that they are suitable for electromobility. In the wake of the energy transition, the demand for high-quality hydrogen tanks has increased. In principle, however, other liquids or gases can also be stored in fibre-reinforced pressure tanks.

Recycling carbon fibre reinforced tapes by unwinding

Such pressure tanks are manufactured in a laser-assisted tape winding process: In this process, thermoplastic glass- or carbon-fibre-reinforced tape is wound over a base body made of plastic, the so-called liner. The unidirectional (UD) tape that covers the pressure tank cannot be reused in the conventional life cycle of the pressure tank and ends up in hazardous waste dumps.

The recycling process patented by Fraunhofer IPT (DE 10 2016 117 559 A1), which it continued to develop in the “Tankcycling” project, makes it possible to remove the UD tape from the liner in a peeling process. In this way, this tape can be reused for other products that are also manufactured with the tape winding process. The Fraunhofer IPT researchers have developed a plant prototype with various modules: the tape passes through one in the recycling process before it is stored onto a spool at the end in another.

Recycling in mini format: The tank recycling module can be connected to a robot head

In downstream tests, the scientists checked the mechanical load-bearing capacity of the recycled material and the original material. Here it was shown that the recycling process did not reduce the quality of the material significantly. Destructive standard tests demonstrated that the recycled material had lost only five to ten percent of its mechanical quality compared with the virgin material. Based on these findings, the researchers were able to define the requirements for the recycling process and develop a tank recycling module. This module represents a further development of the recycling process, which was developed on a stationary test rig. In its miniaturized format, the tank recycling module can be attached to a robot arm. This innovation allows pressure tanks with their complex three-dimensional geometry to be fully recycled. In addition, the recycling process and subsequent rewinding of the tape can be automated in this setup.

Reducing material consumption and environmental impact

The recycling process with its implementation in the tank recycling module efficiently explores the limits of what is technically feasible while saving energy, material and costs. By recycling the fibre-reinforced plastic tapes, the process contributes to advancing the sustainable production of future thermoplastic fibre composite products that can be manufactured using the tape winding process.

Source:fraunhofer IPT/jeccomposites

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#composites #recycling #tanks #carbonfiber #cfrp #tape #pressurevessel #hydrogen