The nature of plastics and their social use. (2023)

Herve Millet,†PatriciaVangheluwe, ChristianBlock, ArjenSevenster, LeonorGarcia e RomanosAntonopoulos, The Nature of Plastics and Their Societal Usage, inPlastics and the Environment, 2018, S. 1-20 DOI:10.1039/9781788013314-00001
eISBN: 978-1-78801-331-4
From the book series:Problems in environmental science and technology

The purpose of this chapter is to review the history of plastics, describe the different types of plastics, their uses and benefits, and provide several examples of plastics found in our everyday lives. The current chapter also provides an in-depth look at the qualitative properties of plastics and describes their chemical nature in simple terms.

1 plastics coming soon

The term "plastic" derives from the Greek words "plastics', meaning 'malleable' and 'Plastic' means 'fit'. Both terms refer to the malleability or plasticity of the material during manufacture, allowing it to be moulded, pressed or extruded into a variety of shapes; such as sheets, fibers, sheets, hoses, bottles, boxes and much more.

In addition, the multiple possibilities of modifying its structure or chemical formulation and, therefore, its final properties, allow its use in countless and varied applications. We find them on the packaging of the food we eat, the houses we live in, the cars we drive, the clothes we wear, the toys we play with, and the televisions we watch. Plastics contribute to our comfort, provide countless solutions in our daily lives and help to improve the environmental impact of products in many applications.

Plastics are synthetic or semi-synthetic materials of a chemical nature; are organic materials such as wood, paper or wool. Normally obtained from crude oil, they can also be produced from renewable raw materials.

Scientifically, there are two main categories of plastics: thermoplastics and thermosets. Thermoplastics can be reheated into products, when these end products are reheated the plastic softens and melts again. Plastic bottles, films, cups and fibers are some examples of thermoplastic products. On the other hand, thermoset plastics are found in products such as electronic chips, dental fillings and eyeglass lenses, they no longer melt after "curing".

At the end of their useful life, plastic products can be recycled back into new products, chemical feedstocks or, where this is not possible or sustainable, used for energy recovery to replace virgin fossil fuels.

1.1 The history of plastics

For over a century, plastics have provided meaningful solutions for people. The development of plastic materials began with the use of natural materials with plastic properties (z.B., chewing gum, shellac), then emerged with the development of chemically modified natural substances (z.B.rubber, nitrocellulose, collagen, gallite). Finally, about 100 years ago, the wide range of fully synthetic materials that we would call modern plastics were developed. The first was discovered by Alexander Parkes in 1862 and is now commonly known as celluloid.1

The development of plastic materials has gone through different historical phases and today it is the most used material in the world. In particular, global plastics production has increased from 1.5 million tonnes in 1950 to 335 million tonnes in 2016.2

1.1.1 19th century: The first polymers

While it is widely recognized that plastics are a modern invention, “natural polymers” such as amber, tortoiseshell and horn are abundant in nature. These materials are similar in structure to manufactured plastics and were often used as a substitute for glass (amber) in the 18th century.

The original breakthrough to the first semi-synthetic plastic material - cellulose nitrate - came in the late 1850s and involved modifying cellulosic fibers with nitric acid.

Cellulose nitrate had many false starts and financial failures until a Briton, Alexander Parkes, introduced what was called "Parkesine" in 1862 as the world's first artificial plastic. The failure of this product due to its high manufacturing cost led to the creation of Xylonite by Daniel Spill. This new material began to be successfully found in the manufacture of items such as decorations, knife handles, boxes and more flexible products such as cuffs and collars.

In 1869, the American John W. Hyatt made a revolutionary discovery, a celluloid manufacturing process, a product that could replace natural substances such as tortoiseshell, horn, linen and ivory. This product went into mass production in 1872.

1.1.2 20th century: the plastics revolution begins

Until the early 1900s, it was impossible to use cellulose nitrate at very high temperatures because it was flammable. The development of cellulose acetate brought a solution to this problem, as it was used as a non-flammable "dope" to stiffen and waterproof the fabric wings and fuselage of early aircraft, and later was widely used as "safety film". cinematic. Casein formaldehyde based on skimmed milk and rennet was developed and used to mold buttons, buckles and knitting needles. In the years since, plastics have experienced a revolution and made them an integral part of our daily lives.

1.1.3 Early 20th century: the discovery of Bakelite

In 1907, Belgian Leo Baekeland (who later coined the term plastic) discovered Bakelite, which at the time was mainly used in the booming automotive and radio industries.3

In 1912, polyvinyl chloride (PVC) and polyvinyl acetate (PVA) were discovered by a German chemist, Fritz Klatte. The following year, Jacques E. Brandenbergen, a Swiss engineer, invented cellophane, a transparent, flexible, waterproof packaging material.

1.1.4 1920: Staudinger and polymers

The first injection molding press, invented by Arthur Eichengrün, appeared in 1921.

Meanwhile, a revolution broke out in 1922 when a German, Herman Staudinger,4Father of macromolecular chemistry, he claimed that molecules could join together to form long chains, making them "macromolecules" or polymers. Staudinger provided sufficient evidence for his macromolecular concept and promoted it despite strong opposition from a number of chemists.

Staudinger provided the theoretical foundations of polymer chemistry and made a significant contribution to the rapid development of the polymer and plastics industry - which is why he received the Nobel Prize in Chemistry in 1953.

Another major scientific breakthrough occurred in 1927, when Waldo Semon, an American researcher, discovered a way to plasticize PVC that had been discovered more than a decade earlier. PVC was thus transformed into a flexible material that can be used for flooring, electrical insulation and roofing membranes. Thanks to that, its real development could start.

1.1.5 1930: Plexiglas™ and Nylon™ are first introduced

In 1930 commercial production of polystyrene began. Meanwhile, in 1933, Otto Röhm invented a great product, Plexiglas™, "a crystalline, unbreakable sheet of polymethyl acrylate"5which found an important market in the aeronautical industry.

In 1935, Wallace Carothers, from the DuPont company, was the first to synthesize Nylon™ (polyamide), which became very famous in socks. The first commercial PVC products were launched in 1934 and 1935, they were flooring and tubes, respectively.

Three years later, a Swiss researcher, Pierre Castan, patented the synthesis of epoxy resins originally used in dentistry (for molds and dental appliances) and medicine. Its properties were also useful as a component of glue.

1.1.6 1940: Great use of plastics in World War II

World War II boosted the production and advancement of plastics, which played a key role in the military supply chain. Plastics have been used for just about everything: nylon has been found in parachutes, ropes, bulletproof vests and helmet panels, for example, while Plexiglas™ has replaced glass in airplane windows.

A variety of innovative materials were invented during the war that are still in use today, such as: Polyethylene, polystyrene, polyester, polyethylene terephthalate, silicone and many more.

1.1.7 1950s: The proliferation of household plastics

The 1950s saw the growth of plastics for household use. Decorative laminates were invented, such as Formica™ tables, which were particularly popular in the United States and were used in espresso bars and cafes. During the same period, plastics also became a major force in the apparel industry. Polyester, Nylon™ and Lycra™ fabrics were easy to wash, did not require ironing and were often less expensive than their natural alternatives.

In 1953, an American chemist named Daniel Fox discovered polycarbonate, a new type of thermoplastic that was very durable and nearly bulletproof. Today it can be found in many modern products such as smartphones.

1.1.8 1960s: Plastics in the fashion industry

The 1960s is known as a decade of mass proliferation of stylish, innovative and impressive plastic products in the fashion world such as: B. Flexible and rigid foams with protective skins, wet looking polyurethane, clear acrylic and faux leather.

Home decor was also enriched, where unconventional designer furniture such as inflatable chairs and acrylic light fixtures became important for fashion-conscious consumers.

In addition, plastic materials played an important role in the manufacture of spacecraft components, their lightness and versatility made them irreplaceable for the success of space exploration.

1.1.9 1970s: Plastics become the most used material worldwide

Without plastics, the technological progress of this era would not have been possible. In mechanical engineering and the computer industry, new polymers have begun to replace the use of metals. Plastics have gained importance in the health area due to their hygienic properties.

1.1.10 1980s: Plastics and the development of communications and transport

The rise of global communications had a direct impact on the production and use of plastics, which provided raw materials for making personal computers, fiber optic cables and portable telephones.

Demand for plastics in cars has also increased in the transport sector. The first flight tests of an all-plastic aircraft took place in the 1980s. In addition, plastic packaging has become very important when shopping, as it helps to distribute and maintain the quality of the products we buy in supermarkets.

1.1.11 1990s and 2000s: The fundamental role of plastic in society

Consumer demands for longer product shelf life and preservation of freshness have led to the development of plastic packaging with superior barrier properties. Society's greater awareness of the need to save fossil fuels has increased the need for plastic products, which has made it possible to improve the energy efficiency of buildings and reduce fuel consumption in transport.

In the 2000s, plastics became key components to meet society's demanding needs. Plastics are used in multiple applications and are currently essential in the construction of structural elements such as insulation, life support systems, spacesuit fabrics, food packaging, guidance and communication systems, solar panels, etc.

2 How is plastic made?

Derived from organic materials, plastics are now mostly made from fossil raw materials. However, plastics production accounts for only 4-6% of global oil consumption.6

The production of plastic from crude oil begins in the distillation process of an oil refinery, where heavy crude oil is separated into lighter fractions. Each fraction is a mixture of hydrocarbon chains (chemical compounds formed by carbon and hydrogen) that differ in the size and structure of their molecules. One of these fractions, naphtha, is the main raw material for the production of plastics. Naphtha is used to break down the various necessary monomers (ethylene, propylene, styrene,etc.).

These monomers are the building blocks for making plastics through what is known as the polymerization process. The two most important polymerization processes are called polyaddition and polycondensation and both require special catalysts. In a polyaddition process, monomers such as ethylene or propylene simply combine to form long polymer chains. Polycondensation is the process by which the polymer is formed from sequential bonds between monomers, using a small molecule (water, ammonia,etc.) during the pasting process. Each plastic has its own characteristics that depend on the different types of base monomers used, their structure and formulation.

Research and innovation continue to diversify the raw material base for plastics production. Biomass, in particular, can be used to produce so-called bio-based plastics. There are two possible categories of plastics that can be obtained from renewable raw materials. The first includes polymers similar to those derived from crude oil, but whose monomers are produced from biomass: for example, sugar cane can be used to produce ethylene and therefore polyethylene. The second category includes new polymers derived from new monomers. For example, lactic acid and therefore polylactic acid (PLA) can be produced from starch. In 2017, global production of bioplastics was around 2 million tons.7

2.1 The different types of plastics

There are different types of plastics that can be divided into two main families of polymers,thermoplasticetermofixos.

thermoplasticare a family of plastics that can melt when heated and harden when cooled. These homonymous properties are reversible. That is, it can be repeatedly reheated, reshaped and hardened. This quality also makes them mechanically recyclable.

thermofixes:Thermosetting or thermosetting plastics are synthetic materials that chemically change when treated, forming a three-dimensional network. Once heated and shaped, these molecules cannot be fused and reformed again.

2.1.1 thermoplastic

Thermoplastics can be categorized according to the organization of their chemical structure and the level of their properties and performance.illustration 1🇧🇷 They account for nearly 80% of plastics demand.

2.1.1.1 standard plastics

Commodity plastics are the most widely used plastics, accounting for more than 85% of global thermoplastics demand.Figure 2).

Polyolefin:They represent the largest family of thermoplastics (55%), which includes all types of polyethylene (LDPE, LLDPE, HDPE) and polypropylene. They are mainly made from crude oil and natural gas by polymerizing ethylene (PE) or propylene (PP). Thanks to their versatility, polyolefins are used in a wide range of applications, from packaging, automotive, construction, medical, sports to consumer goods. LDPE: Used in plastic film, bags, agricultural film, milk carton liners, electrical wire liners, and heavy industrial bags. LLDPE: used in stretch film, film for industrial packaging, thin wall packaging and heavy, medium and small bags. HDPE: used in boxes and boxes, bottles (for food, detergents and cosmetics), food containers, toys, gas cylinders, packaging and industrial films, pipes and household utensils. PP: Used in food packaging, including yogurt and margarine containers, candy and snack containers, microwave containers, carpet fibers, garden furniture, medical packaging and equipment, luggage, cooking utensils, and pipes.

Polyvinylchloreto:PVC is the third largest thermoplastic and one of the first plastics. It is derived from salt (57%) and oil or gas (43%). It can be in the rigid form, which is mainly used for the manufacture of pipes and fittings or window frames, or in the soft form, as in flooring or cable applications.

polystyrene:Polystyrene (PS) is a thermoplastic polymer that can be solid or foamed. It is made from styrene monomer. It is widely used in packaging, cosmetic packaging, toys, and refrigerator trays, among many other applications.

Expanded polystyrene:Expanded polystyrene (EPS) is a rigid foam with a unique combination of properties such as light weight, insulating properties, durability and excellent processability. EPS is used in thermal insulation boards in buildings, in packaging, padding of valuable goods, and in food packaging.

Polyethylenerephthalate: Polyethylene terephthalate (PET) consists of polymerized units of ethylene terephthalate monomers. It is used in fibers for clothing and in food and beverage containers.

2.1.1.2 engineering plastics

Engineering plastics are a subset of plastic materials used in applications that generally require increased performance in the areas of heat resistance, chemical resistance, impact resistance, fire retardancy, or mechanical strength (Figure 3🇧🇷 They account for 10% of the global demand for thermoplastics.

Acrylonitrile butadiene styrene (ABS) is the most widely used engineering plastic, accounting for one-third of total demand, followed by polyamide (PA), polycarbonate (PC), PET injection molding (PET), polybutylene terephthalate (PBT), polyoxymethylene (POM) and Polymethylmethacrylate (PMMA). A quarter of global demand comes from the two largest market sectors: electrical and electronic applications and consumer goods, with the transportation sector being the third largest single market.

2.1.1.3 high performance plastics

This family includes plastics with very high mechanical and chemical performance, allowing for exceptional end uses and specialized niche products. they includefluoropolymerthe most common known type is called polytetrafluoroethylene (PTFE). Fluoropolymers are among the smoothest and strongest materials. Other high performance plastics include; Polyimide (PI), Polyamideimide (PAI), Polyetherimide (PEI), Polysulfone (PSU), Polyetheretherketone (PEEK), Liquid Crystal Polymer (LCP), Polyphenylenesulfide (PPS) and Polyphthalamide (PPA).

2.1.2 termofixos

Epoxy resins:Its physical state can be changed from a low viscosity liquid to a high melting solid, which means that a wide range of materials with unique properties can be produced. They are used as an inner lining in food and beverage cans and specialty packaging to prevent metal corrosion and thus improve the shelf life of packaged products. They are also used as a protective coating for everything from beds, lawn chairs, office and hospital furniture to shopping carts and bicycles. Most industries use them in protective coating materials. They are used, for example, in special paints to protect the surfaces of ships and oil platforms from the effects of the weather and in wind turbines.

Polyurethane:Polyurethane is a polymer composed of organic units linked by carbamate (urethane) bonds. Most polyurethanes are thermosetting polymers that do not melt when heated, but thermoplastic polyurethanes also exist. Main applications are insulated building panels, mattresses and upholstery, car seats, domestic refrigerators and freezers, footwear, etc. Other thermosetting plastics include phenolics, acrylics, unsaturated polyester and vinyl ester resins.

2.1.3 biodegradable plastics

Biodegradable plastics are plastics that, under certain conditions, can be broken down by microorganisms into water, carbon dioxide (or methane) and biomass. Biodegradable plastics offer a value proposition from a waste management point of view for one-off and/or short-term uses: as bags for collecting organic waste, mulch films or potted plants in agriculture and horticulture, packaging of food and disposable tableware ( used indoors, for example B. at events). An example of biodegradable plastic is PLA.

3 Use of plastics in our daily life

3.1 Packing

Packaging is the main application for plastics, covering around 40% of European plastics demand (Figure 4).

Flexibility, strength, lightness, stability, impermeability and ease of sterilization are the main characteristics of plastics that contribute significantly to the commercial success of this application. In this regard, plastics are a preferred packaging material for all types of commercial and industrial users.

The taste and quality of food is not affected by plastic food packaging. Indeed, the barrier properties of plastics preserve the organoleptic properties of food and protect it from external contamination. This property of plastics is evident in various applications such as packaging films for fresh meat, beverage bottles, edible oils and sauces, fruit yogurt pots or margarine pots.

The main advantages of plastics in packaging are briefly presented in the following sections.

3.1.1 Light as a feather

Plastic is the lightest packaging material. Although 50% of all packaging in Europe is made of plastic, plastic packaging accounts for only 17% of the total weight of packaging on the market.8Furthermore, this weight has been reduced by 28% in the last 10 years. Lightweight packaging means lighter loads or fewer trucks needed to ship the same number of products, helping to reduce transport energy consumption, reduce emissions and reduce shipping costs. It also helps to reduce the amount of waste.

3.1.2 Preservation and preservation of food

Plastic packaging protects and preserves perishable foods for longer. For example, the shelf life of beef can be extended from five to ten days or even more when using state-of-the-art plastic packaging solutions. Another example is Parmigiano cheese, an expensive and perishable product packaged in high-barrier film made up of seven layers of different plastics. If such a complex packaging solution were not available on the market, food producers would have to use significantly more material to ensure a sufficient level of protection. In this way, food waste and the use of preservatives are reduced, preserving the flavor and nutritional value of the food.

3.1.3 provision of comfort

Today's consumers prefer packaging with clear identification and labeling that is easy to open and use. Plastic packaging technology has evolved to make this possible. In the near future, packaging is expected to become smarter, thanks to multifunctional plastic films and surfaces capable of detecting and indicating the state of the product to the consumer, with small and inexpensive chips (RFIDs, based on conductive polymers) thin or enough to be printed on aluminum foil. This “smart” packaging alerts retailers and customers to temperature changes that could affect product integrity or when the expiration date is approaching. Similar potato chips can help with food preparation by letting the consumer know when food has been properly cooked and is safe to eat.

3.1.4 safety and hygiene

Plastic packaging prevents contamination of food and medicine and helps prevent the spread of germs during manufacturing, distribution and presentation. Tamper-proof closures provide additional protection and security, while clear packaging allows people to see food without having to touch it, preventing bruising and other damage.

3.1.5 Environmental benefits of plastic packaging

Plastic packaging offers significant environmental benefits thanks to its light weight and ability to keep food fresh longer than alternative materials. If food were packaged with materials other than plastic, the associated energy consumption would double and greenhouse gas (GHG) emissions would nearly triple.9This was accompanied by a significant increase in package weight.

3.2 build and build

Construction is the second largest application of plastic after packaging (20% of plastic consumption in Europe). It covers a wide and growing range of applications where plastic products make a significant contribution to reducing the environmental impact of buildings and, in particular, their energy consumption. In addition to enabling various functionalities and designs inside the house (flooring, wallpaper, wire winding,etc.), some of the most important applications reside in the building structure, as explained below.

3.2.1 Windows: Saving Energy for Decades

The saving of heat through modern plastic window profiles, due to the enormous technological progress of recent years, makes them the area of ​​choice in low-energy houses. If the 80 million new windows needed in Europe every year were fitted with plastic frames, there would be no need for five large power plants. Furthermore, their durability and resilience means that quality PVC windows can last for over 50 years with little or no maintenance. This saves the cost and time of repairing or repainting them, as well as the financial and energy resources required to replace them. Another advantage is the wide range of design options that plastic window profiles offer. They are available in almost every color, style and mood to suit any type of architecture, from the most modern design to renovated historic buildings.

3.2.2 plastic tubes

Plastics are a common choice for modern water, gas and sewer lines because of their high corrosion resistance, light weight and flexibility, making them particularly durable, easy to install and requiring very little maintenance over time. They help to minimize water losses and represent an economically viable solution.

Plastic pipes make it possible to combat the shortage of drinking water. Often, some areas have too much water, while others have too little. To solve this problem, durable plastic piping systems allow water mains to transport water from plastic-constructed reservoirs to arid areas.

3.2.3 isolation

Plastics effectively insulate against cold, heat and noise. The use of plastic insulating materials allows significant long-term financial and energy savings. Over its lifetime, plastic insulation saves more than 200 times the energy used in its manufacture. Furthermore, the use of plastics significantly contributes to the reduction of energy and GHG emissions compared to other materials. According to studies z.9Medium plastic insulation materials use 16% less energy and generate 9% less greenhouse gas emissions than alternative materials.

The excellent self-insulating properties of plastics make plastic insulation efficient even with a limited amount of material. Plastics allow for optimal use of space, for example in cladding the interior walls of buildings.

Plastic insulation materials are easy to install, very durable and of a high standard throughout the lifetime of the building.

3.3 Transport

In transportation, it's all about finding the right balance between high performance, competitive pricing, style, reliability, comfort, safety, strength, fuel efficiency and minimal environmental impact. Plastics have revolutionized automotive design, performance, safety and functionality. One-mold components have helped manufacturers reduce vehicle assembly time, introduce design innovations quickly and reduce costs. Plastics have helped make cars lighter, thereby reducing fuel consumption and greenhouse gas emissions.

The aircraft industry is a good example of how plastic and design innovation are closely linked. Since the 1970s, the use of plastics in aircraft has increased significantly.

3.3.1 Save energy and reduce greenhouse gas emissions

The quest for lower CO₂-Emissions drive research and design efforts in the automotive sector. By using lightweight plastics in cars, manufacturers can save costs, fuel consumption and CO₂-Emissions: Reducing the body weight of an average car by 100 kg reduces CO2 emissions₂emissions in 10 g km,10while the weight saving of all plastic parts saves up to 750 liters of oil over an average car's lifespan of 150,000 km.11

3.3.2 Crucial to passenger safety

As cars get lighter, there can be concerns that safety will be compromised. On the contrary, plastics are actually crucial components for car safety. Energy-absorbing plastic bumpers, durable polyester fiber seat belts, high-strength nylon airbags and plastic child seats have helped make the cars safer for all road users.

3.3.3 Convenience and cost-effective design

Today's lightweight, durable plastics give designers and engineers the freedom to create innovative design concepts in vehicles that improve passenger comfort at realistic costs. This applies to the cockpit, surfaces, fabrics, lighting and sensors, as well as the vehicle's shape and external accessories such as door handles, mirror frames, hubcaps and rims, as well as front-integrated bumpers.

The all-plastic car is a dream that may be closer to being realized in the next two decades, although it is unlikely to be achieved by 2030. Plastic bodies can certainly help reduce the "CX factor", the drag effect that the wind has on the body of a car. In addition, scientists are already working on a wind-powered towing kite propulsion system for cargo ships, where the kite consists of high-strength, weather-resistant synthetic fabrics, for example.

3.4 electrical and electronics

From simple cables and appliances to smartphones, many of the latest electrical and electronics devices use new generation plastics. Due to their diversity and versatility, plastics contribute significantly to innovation in the electrical and electronics industry. For this reason, designers of electrical and electronic applications rely on plastics for their unique properties, described in the following sections.

3.4.1 resource efficiency

Polymers can help store energy longer. Modern liquid crystal (LCD) flat panel displays, which are well established in today's society, consume less energy than common cathode ray tube displays. Resource efficiency often takes place in unseen places. This is due to the design flexibility of plastic parts in household appliances, such as a tub in a washing machine, which reduce water consumption and allow for the best eco-efficiency rating according to the A+++ energy label rating.

3.4.2 Easy

In small devices like smartphones, the use of plastics has increased along with the number of different types of polymers used. Thanks to plastics, smaller and lighter headphones are possible.

3.4.3 Resistance

Plastics' ability to insulate electrical current, combined with their resistance to shock and mechanical stress, as well as flexibility and durability, makes them ideal for critical applications such as safe, reliable and efficient power supplies.

3.4.4 Fire protection

Where a fire can be started by electrical sources, flame retardants offer a wide range of solutions to prevent ignition - required for product safety by legislation and standards.

Plastics will continue to be a key material in communication and will lead to further miniaturization, so that products (e.g. mobile phone headsets, perhaps in combination with hearing aids) become increasingly "one" with our bodies. .

3.5 Agriculture

For years, the increasing use of plastics in agriculture has helped farmers increase agricultural production, improve food quality and reduce the environmental footprint of their operations. Plastic is an important player in the new agricultural scenario. They are found as covers for greenhouses and small tunnels, mulches, shading nets, bags for hydroponics, pipes for drip irrigation, and covers for waterproofing dams. In short, they play an important role in the development and geographical development of intensive agriculture.

Thanks to plastics, water can be saved and crops can even be grown in desert areas. Plastic irrigation pipes prevent wasting water and nutrients, rainwater can be trapped in reservoirs constructed of plastic, and pesticide use can be reduced by keeping plants in an enclosed space such as a greenhouse or under plastic sheeting to mulch. In addition, pesticide emissions into the atmosphere are reduced as they remain in the plastic packaging.

In the future, the plastics industry will develop more specific films for the food and agricultural industries to maximize yield and allow growth in unfavorable conditions. As agriculture usually takes place in rural areas, which are also an important tourist destination, the plastics industry must consider not only functional but also aesthetic factors.

3.6 medicine and health

Modern healthcare would not be possible without medical plastic products: disposable syringes, IV blood bags, heart tubes and valves, and so on. Plastic packaging is particularly suitable for medical applications due to its exceptional barrier properties, light weight, low cost, durability, transparency and compatibility with other materials.

People's life expectancy and quality of life have increased thanks to medical advances in modern plastics, which were unthinkable 50 years ago and are now commonplace.

3.6.1 Unclog blood vessels

The latest heart surgery procedures use thin tubes (catheters) to unblock blood vessels, while the debris that clogs them can be broken up with a tiny spiral-shaped implant - a stent - placed in the treated artery, which consists of a plastic specially designed for the medical sector and loaded with active ingredients.

3.6.2 Prosthesis

Plastics are used today as orthopedic aids where they align, support or correct misalignments. They can even improve the function of moving body parts or replace a body part and take over its primary function. Synthetic materials also play an important role for diseased arteries that cannot be treated.abovevascular support. An affected section of the aorta is removed and the gap filled with a flexible plastic prosthesis. As a result, the lifeline of the body becomes fully functional again.

3.6.3 artificial corneas

Eye injuries or chronic inflammation such as corneal erosion can affect vision, and when a transplant is unlikely to be successful, a prosthesis is the only hope. Artificial corneas made from a special plastic are now available for treatment. Only 0.3-0.5 millimeters thick, highly transparent, flexible and made from a biomechanical material similar to a natural cornea, they can restore clear vision.

3.6.4 hearing aids

People with severe hearing impairments can now have a plastic implant that brings sound back into their ears. This implant consists of several components - a microphone, a transmitter connected to a microcomputer worn on the body, a stimulator and an electrode array with 16 electrodes for 16 different frequency ranges. By converting acoustic impulses into electrical ones, it bypasses damaged cells and directly stimulates the auditory nerve.

3.6.5 Future of plastics in healthcare

There are many areas in healthcare where plastics can make significant advances. Magnetic resonance imaging (MRI), for example, cannot be used in conjunction with metallic surgical instruments: doctors can visualize a tumor but cannot operate under an MRI scanner. This barrier could be overcome by a new plastic robot without metal or electronic parts. We envision the use of plastic-based microsystems and nanotechnology in medicine, using nanopolymers as drug carriers that directly target damaged cells and plastic microinserts to fight heart disease. Eventually, smart plastics will interact directly with our bodies; For example, scientists are building a new bionic ear coated with smart plastic that stimulates the growth of nerve cells in the inner ear when charged with electricity. Plastics are also used in microelectromechanical systems: these very small plastic devices can be placed on the skin to give instant readings of glucose or lactate levels. Future applications of this technology may include cancer cell detection.

Plastics will also play an important role in the development of robotics. In healthcare, smart systems will certainly improve rehabilitation standards, increase diagnostic accuracy, and even offer alternatives to surgery.

3.7 Sport, leisure and design

Plastics have revolutionized the sport in recent years. From the tracks on which Olympic athletes set new records, footwear, clothing, tents and inflatables, safety equipment (helmets, knee pads) to stadium construction (water and drainage pipes, seats, covers), modern sport depends on plastics. Some application examples are listed below.

3.7.1 Plastics in ball games

Plastic materials are used in almost all types of ball games. For example, thanks to plastics, football has become faster and more technical than ever before. The latest ball production concept - called thermal bonding and using a high solids polyurethane layer on a perfectly bonded surface - results in excellent ball contact responsiveness and sensitivity, a predictable trajectory, significantly reduced water and maximum abrasion resistance.

3.7.2 plastics in sports shoes

Running shoes that weigh just a few ounces offer the strength and flexibility athletes demand. Your running block power can make the difference between victory and defeat. Synthetics play an important role in the design of today's athletic shoes, whether for running, jumping or walking.

Take hiking shoes, for example; The lining and tongue can be made from a loose synthetic fabric that repels water and allows moisture to quickly evaporate from the outside of the boot, keeping the hiker's feet dry in wet conditions and cool in hot weather. The midsole with lightweight plastic padding provides comfort and support, while the plastic foam padding provides added comfort in the insoles.

3.7.3 plastics in tennis

Today, sports manufacturers use synthetic materials to create tennis rackets that are light, strong and have excellent shock absorption systems. Players now have more powerful rackets with greater maneuverability. On some racquet models, the center strings run through a specially designed plastic core embedded in a plastic compound that reduces shock vibration by 45% when the ball hits the racquet. This innovative technology allows tennis enthusiasts of all skill levels to enjoy the benefits of synthetics on their local courts.

3.7.4 plastic in the water

The malleability of composite plastics allows the production of elegant and dynamic hulls with low weight and high strength. Power cruisers, sailing yachts and almost all other ships today have a hull, deck, superstructure and even a mast made of composite materials.

Today's yachts use advanced carbon fiber connections that take yacht racing to a new level. This innovative plastic composite has largely replaced construction methods that use traditional materials, offering greater flexibility, superior performance and faster production speeds.

3.7.5 plastics and children

For nearly 50 years, the world's toy makers have used plastics to create some of the best-known and most popular toys and children's products. From bike helmets and swimming aids to knee pads and other protective sports equipment, plastics help keep kids safe every day. Plastics are one of the most tested, researched, durable, flexible and cost-effective materials on the market today.

3.8 Renewable energy

Plastics are playing an increasing role in renewable energy generation. Examples are the plastic rotor blades of a wind turbine and thin-film photovoltaic systems, in which semiconductors (metallic or organic) are printed onto plastic films. Most importantly, for wind energy, if one-third of the GHG savings made possible by the wind turbine is attributed to the rotor, the GHG savings in the use phase are 140 times greater than the emissions for production. For solar energy, the GHG emission savings during the use phase are 340 times greater than the emissions for production if a quarter of the GHG savings made possible by the PV module is attributable to the plastic film.10

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© The Royal Society of Chemistry 2019 (2018)