HISTORY95 - Plastics Forever

This blog is about the fascinating history of plastics.

After an introduction, I will cover the first semi-synthetic (based on natural substances) plastics, then the development of synthetic (no natural content) plastics, applications of plastics today, growing concerns about plastics, and finally the future of plastics.

 

I will list my principal sources at the end.

 

Introduction

Plastics is a word that comes from the Greek language, meaning “pliable and easily shaped.”  It only recently became a name for a category of materials called polymers, meaning “of many parts,” and made of long chains of molecules.  Polymers abound in nature.  Cellulose, the material that makes up the cell walls of plants, is a very common natural polymer.

While we think of plastic as a 20^th-century material, natural plastics such as animal horn, tortoiseshell, amber, rubber, and shellac have been worked with since antiquity.  In 1600 BC, Mesoamericans used natural rubber for balls, and figurines.  The first written record of shellac appeared in about 1000 BC.  In the Middle Ages, Europeans used treated cow horns as translucent material for windows.  The Japanese and Chinese used ox horns for the same purpose, as well as for shades of oil lamps.  Animal horns, malleable when heated, were used for many purposes and products, from medallions to cutlery.  The comb-making industry was one of the biggest applications of animal horns in the 19^th century. 

19^th-century comb with two circular grips, made in India from incised and carved decoration animal horn.

Over the last two centuries, humans have learned how to make synthetic polymers, sometimes using natural substances like cellulose, but more often using the plentiful carbon atoms provided by petroleum and other fossil fuels.  The long molecule chains of synthetic polymers are arranged in repeating units, often much longer than those found in nature.  It is the length of these chains and the patterns in which they are arrayed that make polymers strong, lightweight, and flexible.  

These properties make synthetic polymers exceptionally useful, and since we learned how to create and manipulate them, polymers have become an essential part of our lives.  Their plasticity makes it possible for plastics to be molded, extruded, or pressed into solid objects of various shapes.  This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to its widespread use.

The world's first fully synthetic plastic was Bakelite, invented in New York in 1907, by Leo Baekeland, who coined the term "plastics.”   Dozens of different types of plastics are produced today, such as polyethylene, which is widely used in product packaging, and polyvinyl chloride (PVC), used in construction and pipes because of its strength and durability. 

In developed economies, about a third of plastic is used in packaging and roughly the same in buildings in applications such as piping, plumbing, or vinyl siding.  Other uses include automobiles (up to 20% plastic), furniture, and toys.  Plastics pervade all aspects of society.  We sleep on plastic-filled pillows, clean our teeth with plastic toothbrushes, type on plastic keyboards, drink and eat food from plastic containers; it’s impossible to go through a day without encountering plastic of some kind.

But as we are becoming increasingly aware, our widespread adoption of plastics has caused widespread environmental problems, due to their slow decomposition rate in natural ecosystems.  Most plastic produced has not been reused, or is incapable of reuse, either being captured in landfills or persisting in the environment as plastic pollution.  Plastic pollutes our landscapes, oceans, air, and bodies, and remains a contentious issue for our future.  

 

The First Semi-Synthetic Plastics

By the middle of the 19^th century, in the wake of industrialized goods production, some animal-derived materials had become increasingly scarce.  Elephants were facing extinction if demand for their ivory, used in items from piano keys to billiard balls, continued.  The same fate awaited some species of turtle, whose shell was harnessed for combs.  

Inventors attempted to tackle this environmental and economic problem, with many patents for new materials based on natural substances (semi-synthetic plastics).

One of the earliest was cellulose nitrate - cotton fibers dissolved in nitric and sulfuric acids, then mixed with vegetable oil.  Its inventor, English chemist Alexander Parkes, patented this new material in 1862 as Parkesine.  Considered the first man-made plastic, it was a cheap and colorful substitute for ivory or tortoiseshell, but the manufacturing process was complex and costly. 

English chemist Alexander Parkes produced the first man-made plastic.

 

In 1869, American inventor John Wesley Hyatt simplified the manufacturing process for a similar compound, blending camphor with nitrocellulose, and produced a hard, moldable substance he dubbed celluloid, a plastic that could be crafted into a variety of shapes and made to imitate natural substances like tortoiseshell, horn, linen, and ivory.  In addition to creating this new material, he developed the necessary machinery for working it.   Hyatt and his brother began producing celluloid in quantity in 1871, marketing it as a substitute for natural materials like ivory and tortoiseshell, and created and sold objects like dental plates, jewelry, combs, mirrors, toys, baby rattles, and even shirt collars. 

American John Wesley Hyatt invented celluloid plastic and simplified the manufacturing process for similar compounds

 

Undoubtedly, celluloid’s greatest cultural application was movie film.

Celluloid plastic was used in the first movie films

 

Development of Synthetic Plastics

In 1907, Belgian-American chemist Leo Baekeland invented Bakelite, the first fully synthetic plastic, meaning it contained no molecules found in nature.  Baekeland had been searching for a synthetic substitute for shellac, a natural electrical insulator, to meet the needs of the rapidly electrifying United States.  His invention combined two chemicals - formaldehyde and phenol - under heat and pressure. 

Belgian-American chemist Leo Baekeland invented Bakelite, the first fully synthetic plastic.

 

Bakelite was not only a good insulator; it was also durable, heat resistant, and, unlike celluloid, ideally suited for mechanical mass production.  Marketed as “the material of a thousand uses,” Bakelite could be shaped or molded into almost anything, providing endless possibilities.

Bakelite telephone made in the 1930s.

 

Hyatt’s and Baekeland’s successes led major chemical companies to invest in research and development of new polymers, and new plastics soon joined celluloid and Bakelite. 

In the early decades of the 20^th century, the petroleum and chemical industries began to form alliances into companies like Dow Chemicals, ExxonMobil, DuPont, and BASF - driven by the desire to make use of waste material from processing crude oil and natural gas.  These companies are still the major producers of raw materials for the plastics industry today.

One of the most abundant of these byproduct waste materials was ethylene gas.  In 1933, a team at the British firm of Imperial Chemical Industries (ICI), was attempting to combine ethylene and benzaldehyde under great pressure and heat.  The experiment failed.  Instead, due to a leak of oxygen into the vessel, they found a white waxy substance in a reaction tube.  This was found to be a polymer of ethylene.  Now the world’s most abundant plastic, polyethylene was a wonder material: strong, flexible, and heat-resistant.

Polyethylene’s first application was insulating radar cabling during the Second World War, but consumer products soon followed, from the plastic shopping bag and Tupperware to artificial hip and knee joints.

ICI’s U.S. rival DuPont had a series of plastic successes in the 1930s, notably Nylon and Teflon.  Nylon, invented by Wallace Carothers in 1935 as a synthetic silk, was used during the war for parachutes, ropes, body armor, helmet liners, and more.  Nylon stockings were an immediate worldwide sensation.  Another plastic, plexiglass, provided an alternative to glass for aircraft windows.

Two pairs of Triumph nylon stockings from the 1950s.

 

A Time magazine article noted that because of the war, “plastics have been turned to new uses and the adaptability of plastics demonstrated all over again.”  During World War II plastic production in the United States increased by 300%.

The surge in plastic production continued after the war ended.  After experiencing the Great Depression and then World War II, Americans were ready to spend again, and much of what they bought was made of plastic.  According to author Susan Freinkel, in her 2011 book Plastic:  A Toxic Love Story, “In product after product, market after market, plastics challenged traditional materials and won, taking the place of steel in cars, paper and glass in packaging, and wood in furniture.”  The possibilities of plastics gave some observers an almost utopian vision of a future with abundant material wealth thanks to an inexpensive, safe, sanitary substance that could be shaped by humans to their every whim.

 

Applications for Plastics

Plastics are used today for an incredible variety of products in the modern world.  As the chart below shows, the amount of plastic produced in the world every year has increased explosively in just a human lifetime.  Some of the most common uses of plastic listed after the chart.

Plastics production from 2 million tons in 1950 to over 390 million tons in 2021.  The expectation is that the production will increase to about 1480 million tons by 2050. 

Application of plastics today include: 

1.  Packaging:  Ideal material to use for product packaging.  Plastics are adaptable, hygienic, light, flexible, and durable.  Packaging is thus responsible for most of the plastics used globally, coming in the form of vending packaging, baby products, protective packaging, containers, bottles, drums, trays, boxes, cups, shopping bags, and much more.

2. Construction: Economically appealing thanks to their outstanding strength-to-weight ratio, cost effectiveness, durability, low maintenance requirements, and corrosion resistance.  Plastics are used in, among other things, water supply and sewage pipes, insulation, roofing materials, windows., gutters, and doors.

3. Electronics: Can protect electronic components and allow for easy assembly because they are non-conductive.  This is why you find plastic in computers, phones, televisions, household appliances, insulation on wires, and communication equipment. 

4. Transportation: Used in various parts of automobiles, including dashboards, bumpers, engine parts, headlights, wing mirrors, interior panels, and upholstery.  Since plastics are both lightweight and durable, they reduce the vehicle’s weight and improve fuel efficiency.  The same goes for other types of transportation including airplanes, rockets, trains, and boats.

5. Clothing:  Used for textiles after conversion into synthetic fibers and fabrics.  Modern clothing and upholstery commonly include plastics, including stretchable fabrics and fleece.   For example, polyester, which is a flexible, water-resistant synthetic fiber, is used for making blouses, sweaters, jackets, and underwear.  Plastics are also used in space suits, protective vests, and safety helmets.

6.  Medical Devices:  Application include, but not limited to, disposable syringes, IV and blood bags, prosthetic limbs, implantable devices, dialysis machines, heart valves, tubing, and wound dressing.  Medical-grade plastics are sterile and biocompatible and can be easily molded into complex shapes.  Plus, they’re often less expensive than traditional medical materials.

7.  Furniture:  Applications include bedding, upholstery, household furniture, and carpets.

8.  Energy Generation:  Used in wind turbines, solar panels, and ocean wave energy conversion panels

9.  Consumer Goods:  Often used in the production of toys because they can be molded into various shapes and colors. Plastic toys are durable and lightweight, so they withstand wear and tear.  Other consumer goods include tableware (glasses, spoons, forks, etc.) and toothbrushes.

 

 Growing Concerns About Plastics

Following World War II, along with the tremendous increase in the use of plastics and the explosion of plastics production shown above, there have been growing concerns.

The chemical properties that have made plastic an incredibly useful and durable material also make it difficult to dispose of, with some types taking thousands - even tens of thousands - of years to degrade in landfills. 

The degradation itself is an even bigger environmental issue, as the breaking down of plastics into microscopic particles pollutes our ocean, air, and ecosystems. The health implications of microplastic deposits in our bodies are not yet fully known.  

And since the modern plastics industry relies on fossil fuels for its raw material, the production of plastic has an impact on climate change, contributing to global C02 production. 

Plastic debris in the oceans was first observed in the 1960s, a decade in which Americans became increasingly aware of environmental problems.  Rachel Carson’s 1962 book, Silent Spring, exposed the dangers of chemical pesticides.  In 1969, a major oil spill occurred off the California coast and the polluted Cuyahoga River in Ohio caught fire, raising concerns about pollution.  As awareness about environmental issues spread, the persistence of plastic waste began to trouble observers.    

Plastic’s reputation fell further in the 1970s and 1980s as anxiety about waste increased.   The ultimate symbol of the problem of plastic waste is the Great Pacific Garbage Patch, which has often been described as a swirl of plastic garbage the size of Texas floating in the Pacific Ocean.

Plastic rubbish in the ocean near Roatan, an island off the coast of Honduras.

 

It was the plastics industry that offered recycling as a solution.  In the 1980s, the plastics industry led an influential drive encouraging municipalities to collect and process recyclable materials as part of their waste-management systems.  However, recycling is far from perfect, and most plastics still end up in landfills or in the environment.  Grocery-store plastic bags have become a target for activists looking to ban one-use, disposable plastics, and several American cities have already passed bag bans. 

There are a lot of different types of plastic available today, each with its own unique set of properties and uses.  The most prominent types of plastic are listed in the chart below, organized by recyclability category, and showing common plastic products in each category.  (These recyclability codes are commonly printed on today’s plastic products.)

Types of plastic by recyclability code.

 

Among the worst pollution offenders, along with polyethylene shopping bags and polystyrene food containers, are polyethylene terephthalate (PET) drink bottles.  The economics of mass-produced, cheap plastic products have led to a single-use culture, and today around 500 billion PET bottles are sold every year.  This figure is increasing, and many of these bottles end up in our oceans, degrading into microplastics. 

The reputation of plastics suffered further thanks to a growing concern about the potential threat they pose to human health.  These concerns focus on the additives (such as bisphenol A, commonly known as BPA, and a class of chemicals called phthalates) that go into plastics during the manufacturing process, making them more flexible, durable, and transparent.  Some scientists and members of the public are concerned about evidence that these chemicals leach out of plastics and into our food, water, and bodies. In very high doses these chemicals can disrupt the human endocrine (or hormonal) system.  Researchers worry particularly about the effects of these chemicals on children and what continued accumulation means for future generations.

Even for containers labeled “safe” for the microwave and dishwasher, experts caution that heat and plastic don’t mix well. Since heat helps to break the chemical bonds in plastic, it’s possible that exposure to high temperatures increases the rate of chemical migration from the container into the food.  Scientists have documented higher rates of chemical migration even in water bottles left in the sun.

To reduce greenhouse gas emissions, chemists have researched and developed green plastics, which - like early semi-synthetic plastics - are derived from natural, biological material such as corn starch.  In 1990, ICI, the British innovators of polyethylene, developed the first practical biodegradable plastic, Biopol, which was first used in a Wella shampoo bottle.  These materials are becoming increasingly common in single-use packaging.   But not all bioplastics are better in terms of disposing or recycling. 

One of the biggest barriers to plastic recycling is separation: when different polymers are mixed, the resulting material does not usually have useful properties.  Even two PET items, a drink bottle and cookie cutter, for example, may have different melting temperatures that produce an unusable sludge when combined.  At the moment, chemical means of sorting plastics are not economically viable on a big scale, so it’s down to human sorters to do the job. 

Recycled plastic items have become marketable and fashionable in the 21^st century era of increasing environmental consciousness, where the original use of the material is often named on the product. 

 

The Future of Plastics

Despite growing concerns, plastics are critical to modern life.  Plastics made possible the development of computers, cell phones, and most of the lifesaving advances of modern medicine.  Lightweight and good for insulation, plastics help save fossil fuels used in heating and in transportation.  Perhaps most important, inexpensive plastics raised the standard of living and made material abundance more readily available.  Without plastics, many possessions that we take for granted might be out of reach for all but the richest Americans.  Replacing natural materials with plastic has made many of our possessions cheaper, lighter, safer, and stronger.

Since it’s clear that plastics have a valuable place in our lives, scientists are attempting to make plastics safer and more sustainable.  Innovators are developing bioplastics, which are made from plant crops instead of fossil fuels, to create substances that are more environmentally friendly than conventional plastics.  Others are working to make plastics that are truly biodegradable.  Some innovators are searching for ways to make recycling more efficient, and they even hope to perfect a process that converts plastics back into the fossil fuels from which they were derived.

All of us recognize that plastics are not perfect, but that they are an important and necessary part of our future.

 

[A]Plastic pollution free world is not a choice but a commitment to life - a commitment to the next generation.

 Amit Ray, Indian author and spiritual master

 

Sources

My principal sources include: “Plastic” and “Timeline of plastic development,” en.wikipedia.org; “History and Future of Plastics,” sciencehistory.org; “The Age of Plastic: From Parkesine to Pollution,” sciencemuseum.org; “American History Highlights Celluloid and the Dawn of the Plastic Age,” smithsonianmag.com; “Plastics Applications,” bpf.co.uk; “Plastic: Definition, Types, Properties, Advantages, and Disadvantages,” xometry.com; plus, numerous other online sources.