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Plastics and Sustainability

Scrivener Publishing 3 Winter Street, Suite 3

Salem, MA 01970

Scrivener Publishing Collections Editors

James E. R. Couper Richard Erdlac Norman Lieberman W. Kent Muhlbauer S. A. Sherif

Ken Dragoon Rafiq Islam Peter Martin Andrew Y. C. Nee James G. Speight

Publishers at Scrivener Martin Scrivener (martin@scrivenerpublishing.com)

Phillip Carmical (pcarmical@scrivenerpublishing.com)

Plastics and Sustainability

Towards a Peaceful Coexistence between Bio-based and Fossil

Fuel-based Plastics

Michael Tolinski

Scrivener

WILEY

Copyright © 2012 by Scrivener Publishing LLC. All rights reserved.

Co-published by John Wiley & Sons, Inc. Hoboken, New Jersey, and Scrivener Publishing LLC, Salem, Massachusetts. Published simultaneously in Canada.

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Library of Congress Cataloging-in-Publication Data:

ISBN 978-0-470-93878-2

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Contents

Acknowledgements xi Preface xiii

1 General Introduction 1

1.1 What is Environmental Sustainability? 4 1.2 Facing the Contradictions of Plastics 8 1.3 Plastics at Play in Consumer Lifestyles 10 1.4 Controversies Concerning Plastics:

Recent Examples 11 1.4.1 PVC and Phthalate Plasticizers 12 1.4.2 Plastic Shopping Bags 14 1.4.3 Health Effects of BPA (Bisphenol-A) 16

1.5 The Desire to be "Green" 19 1.5.1 Consumer Interest in Sustainability 19 1.5.2 Sustainability: Views and Counterviews 21

1.6 The Course of This Book: A Chapter-by-Chapter Overview 26

References 29

2 The Life Cycles of Plastics 31

2.1 "Green Principles" - A Basis for Discussion 33 2.2 Life Cycle Assessment (LCA) - A Baseline Tool 37

2.2.1 Life Cycle Inventory (LCI) 39 2.2.2 LCA: Controversies and Limitations 40 2.2.3 LCA/LCI: Plastics-related Examples 43

v

vi CONTENTS

2.3 Plastic Lifetimes: Cradle-to-Gate... to Gate-to-Grave 2.3.1 The "Cradle": Polymer Feedstocks

and Production 2.3.2 "Gate-to-Gate": General Plastics

Use-life Impacts 2.3.3 The "Grave": Disposal, Recycling,

and Biodegradability 2.4 Towards a Hierarchy of Choosing Plastics

for Sustainability References

46

46

50

52

66 68

3 Polymer Properties and Environmental Footprints 73

3.1 Background on Polymers and Plastics 75 3.1.1 "Green Chemistry" Principles Most Relevant

to Plastics 76 3.2 Common Commodity Thermoplastics 82

3.2.1 Polyethylene (PE) 82 3.2.2 Polypropylene (PP) 87 3.2.3 Polyvinyl Chloride (PVC, or "Vinyl") 89 3.2.4 Polystyrene (PS) 91 3.2.5 Polyethylene Terephthalate (PET) and Related

Polyesters 92 3.3 Traditional Engineering Thermoplastics 95

3.3.1 Nylon or Polyamide (PA) 96 3.3.2 Acrylonitrile-Butadiene-Styrene (ABS) 97 3.3.3 Polycarbonate (PC) 99

3.4 Traditional Thermosets and Conventional Composites 100 3.4.1 Unreinforced Thermosets 101 3.4.2 Conventional Composites 103

3.5 Biopolymers: Polymers of Biological Origin 104 3.5.1 Polylactic Acid (PLA) 106 3.5.2 Polyhydroxyalkanoates (PHAs):

PHB and Related Copolymers 110 3.5.3 Starch-based Polymers 113 3.5.4 Protein-based Polymers 114

CONTENTS vii

3.6

3.5.5 Algae-based Polymers 3.5.6 Blends of Biopolymers Additives and Fillers: Conventional and Bio-based 3.6.1 Common Additives 3.6.2 Fillers 3.6.3 Fiber Reinforcement 3.6.4 Nanocomposites Concluding Summary rences

115 115

116 117 118 119 125 125 126

3.7

Applications: Demonstrations of Plastics Sustainability 133

4.1 Trends in Sustainable Plastics Applications 136 4.2 Sustainable Plastics Packaging 137

4.2.1 Traditional Plastics Bags and Containers: Use, Disposal, and Recycling 140

4.2.2 Bio-based Plastic Packaging 142 4.2.3 "Greener" Foam Packaging 144 4.2.4 Key Points about Plastics Packaging

and Sustainability 146 4.3 Sustainable Plastics in Building

and Construction 146 4.3.1 Recycled / Recyclable Construction

Applications 149 4.3.2 Wood-plastic Composites 150 4.3.3 Key Points about Plastics Sustainability

in Construction 151 4.4 Automotive Plastics and Sustainability 152

4.4.1 Fuel-saving Contributions of Plastics 152 4.4.2 Recycling and Automotive Plastics 154 4.4.3 Bioplastics in the Automotive Industry 155 4.4.4 Key Points: Plastics Sustainability

in the Automotive Industry 157 4.5 Specialized Applications and Plastics Sustainability 158

4.5.1 Electrical/Electronics Applications 158 4.5.2 Medical Plastics and Packaging 159

viii CONTENTS

4.5.3 Agricultural Applications 161 4.6 Conclusions about Sustainable

Plastics Applications 162 References 163

5 Design Guidelines for Sustainability 169

5.1 Green Design Principles 172 5.1.1 Minimize Material Content 174 5.1.2 Exploit a Material's Full Value

in the Design 175 5.1.3 Design Only to Fulfill Service

Durability Requirements 178 5.1.4 Minimize Non-functional Features 179 5.1.5 Focus on Single-material Designs 179 5.1.6 Incorporate Renewable Content 182

5.2 The Wildcard: Consumer Preferences in Green Design 183

References 184

6 Sustainable Considerations in Material Selection 187

6.1 A Broad Example of Materials Selection: Plastics vs. Metals and Glass 191

6.2 Material Selection for Common High-Volume Plastics Applications 193 6.2.1 Plastics Selection for Beverage Bottles: PET vs.

rPET vs. bio-PET 193 6.2.2 Plastics Selection for Thermoformed

and Flexible Packaging 197 6.2.3 Selection for Housewares and Food

Service Tableware 199 6.3 Bio-based Plastic Selection 202

6.3.1 Selecting Bio-based Resins: PLA, PHA, TPS, and Bio-based PE 203

6.3.2 Selecting Natural Fiber Plastics Reinforcement 207

6.3.3 Selecting Engineering (Bio)polymers 212 6.4 The Selection Process: A Visual Approach 214 References 219

CONTENTS ix

7 Processing: Increasing Efficiency in the Use of Energy and Materials 221

7.1 Optimizing Resin Recycling 223 7.1.1 Reprocessing Scrap and Post-industrial

Material 223 7.1.2 Recycling Technologies for Post-consumer

Plastic 226 7.2 Optimizing Plastics Processes for Sustainability 231

7.2.1 Optimizing Process Water Use 231 7.2.2 Optimizing Process Energy Consumption

of Existing Machinery 233 7.2.3 Choosing New Machinery for Sustainability 236 7.2.4 Sourcing Options for "Green"

Processing Energy 237 References 238

8 Conclusion: A World with(out) Sustainable Plastics? 241

8.1 Trends Affecting Future Global Plastics Use 244 8.1.1 Consumer Needs and Market Growth 244 8.1.2 Fossil Fuel Availability and Price 247 8.1.3 Alternative Feedstock Trends 248 8.1.4 Industry Priorities in Responding

to Calls for Sustainability 250 8.1.5 Plastic Bans and (Never Ending?)

Controversies 252 8.2 Future Progress in Promoting Plastics Sustainability 256

8.2.1 Improved Partnerships, Standards, Industry Practices, and Public Education 256

8.2.2 New Sustainability-Enhancing Uses of Both Fossil- and Bio-based Plastics 265

8.2.3 From R&D to Real World: Newer, More Renewably Based Polymeric Materials 268

References 269

Index 273

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Acknowledgements

Solving problems related to the sustainability issues surrounding plastics must be a collaborative process if it is to be fruitful. This book acknowledges that need for collaboration by referencing the research and arguments of hundreds of industry professionals who have studied and/or reported on sustainability issues over recent years. These professionals often address difficult, critical technical issues that are typically not reported on by the mainstream press, but which are essential for understanding the overall argument about plastics and sustainability. I appreciate the commitment of these people; their work is admirable, especially the efforts of those who have presented complex views on sustainability while still trying to balance the interests of all stakeholders.

I also want to thank the editorial staffs at the Society of Plastics Engineers and John Wiley & Sons in Hoboken, who over the past eight years have often given me "free rein" to focus my articles for Plastics Engineering magazine on sustainability issues in the industry. The research required greatly aided me in creating this book. I also wish to thank those who commented on early drafts of the book, and my publisher Martin Scrivener for his interest, helpful guidance, and patience.

X I

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Preface

Years ago, after my first career as a manufacturing and materials engineer in the automotive industry, I started working as a trade journalist covering the plastics industry. I was eager to demonstrate my experience working with plastics in durable automotive appli-cations, though I wasn't really comfortable with the ways plastics were used for packaging and other disposable applications. In one of our first meetings for a new (and short-lived) plastics magazine, I remember confessing that I wasn't thrilled to be writing about a technology that "produces billions of margarine tubs and dispos-able stuff."

A much more experienced senior editor shook his head and responded solemnly with what I think was meant to be a correc-tion and a lesson for me to learn: "It's not our job to pass judgment on whether certain technologies in the industry are appropriate or inappropriate to cover." In terms of magazine publishing, he was right after all. Trade magazines in particular depend on advertising revenue from various companies they report on, and any magazine professing to cover the plastics industry inclusively should report on all its applications and machinery. I guess I even kept this les-son in mind when I was writing my first book, which focused on polyolefins - the family of polymers from which those margarine tubs are made.

But now the situation seems different. Questions arise daily in the public discourse and within the industry itself about the envi-ronmental footprint or appropriateness of certain materials and technologies. More and more often, these decisions revolve around the concept of environmental sustainability.

Some arguments about the environmental impacts of plastics, though outwardly based on facts and logic, are, at their core, based

xiii

xiv PREFACE

on values and emotion. Aside from their technical prowess, plastics industry people are proud of the capabilities of their products and of the unique qualities of plastics, compared with other materials. They have spent their careers perfecting technology intended to make daily life better for billions of people. On the extreme other side, environmental activists are particularly sensitive to the waste of resources and the damage to the earth's systems that can be cre-ated by technological society. And they are sensitive to the effects of industrial materials on children and future generations (or they may simply wish to avoid plastics for aesthetic or philosophical reasons).

The plastics industry's positions usually focus on defining the "true" level of risk or danger that environmental researchers raise about plastics (though certainly there are always holes to be poked in any study). According to their positions on various issues raised about plastics and the environment, each side has developed its own network of organizations that study the environmental effects of plastics. These groups publish reports, lobby governments for/ against new laws, and use the mass media (and social media) to present their case.

In these kinds of disputes, each side argues for the legitimacy of its positions, conclusions, and test data. But care must be taken when using their information in making conclusions, given the possible biases that may influence each study. For this reason, this text avoids, as much as possible, referencing studies that seem excessively and intentionally biased. When a source seems like it could be biased, the text makes the source obvious in the text where it is referenced, so that the reader can consider any potential bias in the source material while reading. (And when the sources are not mentioned in the text, readers can refer to the authors or authoring organizations of each source in the references lists; most of these source materials are easily available online.)

This book assumes the reader has some basic knowledge about plastics (with at least some undergraduate organic chemistry being helpful). The reader should know some basic concepts of polymer science - that plastics are composed of polymers and additives, that polymers are long-chained organic molecules composed of repeating units of relatively simple chemical units, and so forth. The reader should also know that there are various chemistries behind what the public commonly labels as "plastics," and that

PREFACE XV

these materials are formulated to have wide ranges of properties essential for post-industrial products and lifestyles.

At first glance, it may appear that this book was written for man-agers or decision makers in the plastics industry, or even for a much more general audience. The book includes no structural formulas for polymers or sophisticated graphs. It even leads off each chap-ter with the thread of a fictional story about a plastics packaging company. This fragmented short story is mainly intended to illus-trate the challenges of making decisions about sustainability in a real-world manufacturing environment of profit and loss, of eco-nomic uncertainty, and of personalities and opinions. The efforts made and information needed by the characters in the story are reflected by each chapter's contents. The story is meant to provide some insight for readers who have not worked in such facilities. And those readers who have worked in the industry hopefully can at least relate to parts of the story. (Note that the elements of this fic-tional scenario are not intended to represent any specific company or any actual people ever known to me, living or now dead.)

The overall argument of the book is not simple: it is not p ro / con or for/against plastics in general, or pro-bioplastics, anti-tradi-tional plastics. Given my background working inside the industry and with industry publications, readers might assume there could be a pro-plastics agenda embedded in the book. This is not the case. The book's essential argument is that with careful thought about multiple issues, optimally sustainable decisions can be made about the use of industrial materials such as plastics. However, decisions about what a sustainable use of plastics is will never be perfect, obvious, or self-evident - after all, even the definition of sustainabil-ity is difficult to pin down. The best decision-making process will consider multiple factors before settling on the best practical choice of material for a specific application in terms of environmental sus-tainability and public acceptance.

August 2011 Plymouth, Michigan

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2 General Introduction

This introductory chapter will address fundamental, current questions of interest related to plastics and sustainability. As with the other chapters in this book, this chapter will begin with a brief outline of its contents. This will be followed by an epi-sode from a fictional scenario about plastics industry people who are dealing with real-world sustainability decisions. Each of the following chapters will continue this story, following the char-acters' progress as they consider how to best reduce the overall environmental impact from the selection, processing, use, and disposal of plastic materials. The main content of each chapter provides details that the characters - and similarly interested readers - might consider when making sustainability decisions about plastics.

This chapter will define terms and arguments related to issues of environmental sustainability, restating arguments in ways that best highlight the challenges that plastics-consuming companies can focus their energies on. It will briefly introduce issues that are covered later in the book in more detail, also linking some

1

2 PLASTICS AND SUSTAINABILITY

well-known plastics controversies with the broader context of this book. Specifically, this chapter will:

• define environmental sustainability in terms of plas-tics production and use (1.1);

• present an overview of the sometimes contradictory positive and negative features of polymer-based mate-rials (1.2);

• illustrate consumers' dependence on plastics in their plastics-based lifestyles (1.3);

• provide a brief history of recent (and often controver-sial) sustainability issues concerning plastics (1.4);

• discuss the "need for green" - especially the social pressures that are forcing plastics manufacturers to take sustainability seriously (1.5); and

• provide an overview of the chapters in the remainder of the book (1.6).

Part 1:Company at a Crossroads

It's 2011, and SureShot Inc. finds itself at a crossroads after fifteen years of existence. It started as a relatively small company making injection-molded rigid food containers and housewares, mainly made from poly-ethylene and polypropylene. A few years ago, the company expanded the plant, adding a couple of thermoforming lines to produce PET food containers, such as clear clamshells and trays for produce and deli foods. The company managed to survive the 2008-2010 "Great Recession" with relatively few layoffs, though some areas of its production floor that it had planned to fill with activity are still inactive (or empty).

Business is slowly returning to pre-2008 levels, but new issues are growing in importance. Calls for environmental sustainability are focus-ing more attention on the plastic packaging industry's roles and responsi-bilities in determining how its products are created, used, and discarded. Governments are considering bans on various single-use plastic products, and the plastics consuming public seems to be more conscious of the mate-rial that is used for these products, where the material comes from, and how it's disposed of.

Considering all of these issues is Guy Winston, general manager of SureShot's ISO-employee operation. He's proud of his 20-year career in the plastics industry, but lately he's been wondering about his company's role in the sustainability argument. He knows his operation covers the basics of environmentally efficient production - his equipment is fairly

GENERAL INTRODUCTION 3

energy-efficient (except for a few older machines), the plant's scrap mate-rial is fed back into appropriate processes and products when possible, and the company even manufactures a line of lettuce containers that contain some post-consumer recycled PET bottle content (although this business is less than 3% of the company's total production). But he's starting to think that they could do more.

The industry trade journals are stuffed with articles about bioplastics, bioresins, bioadditives, and "bio-everything-else." Plastics made from renewable feedstock materials rather than fossil fuels seem to be the next big thing. But what is the market for these materials? Don't they cost more? Wouldn't SureShot have to increase its prices? Do bioresins have adequate properties, compared with the current PET, PE, and PP grades the plant uses? Do they process as easily and as consistently too?

Sheila Wolfe, SureShot''s young head of engineering development, was recently hired after business started to improve last year. With a Master's Degree in Engineering and an MBA in hand, she certainly has an educa-tional background that Guy doesn't. And she's extremely excited to try out bioresins in a couple of product lines. "We have to start making the shift to bioresins as soon as possible, or we'll be left behind," is her consistent position. She's enthusiastic, but fortunately is still mostly objective - yet Guy ivonders if her inexperience with high-volume packaging operations hurts her credibility on this issue. After all, she was in elementary school when Guy started his career as a manufacturing engineer. Sometimes it's obvious that she didn't witness firsthand how much SureShot's business suffered during the recession.

In Guy's mind, the "Great Recession" period still weighs heavily. "We have to make sure we keep on making money and keep everyone employed," is an obsessive thought he continues to have - and he cannot shake the nervousness he experienced when hearing about the bad fortunes of other similar-size plastics products companies that shut down operations in recent years.

Another colleague is influencing Guy's thoughts. Often seen wander-ing through the plant is Paul "Tubs" Kirmidgin, SureShot's hands-on president, CEO, and founder. He's definitely "old school," and not a strong supporter of many pro-environmental initiatives, to say the least. "Now they've got even The Wall Street Journal convinced that these bioplastics are going to be important," he complained to Guy one day. "Ridiculous - making plastics from crops - our food - plus it's expensive. No, there's plenty of natural gas and oil in the ground to make plastics from, and only a few percent of that is used to make plastics anyway. Guy, I trust you already know all these things." Fortunately for Guy, the wiry, energetic 70-year-old (usually) resists interfering with Guy's management of the

4 PLASTICS AND SUSTAINABILITY

operation. Even though behind the scenes they often disagree, Guy was originally hired and promoted by Paul, who remains a father figure to him, of a sort.

With Sheila's and Paul's diverse opinions surrounding him, Guy has decided to thoroughly study all the issues related to plastics' environmental footprints and bio-based plastics. There are some real questions to con-sider first off. For example, has the traditional plastics industry gone in wrong directions in the past - hurting its image and even creating real harm to the environment? And are developments such as bio-based plastics better directions in which the industry - and SureShot Inc. -should be moving?

1.1 What is Environmental Sustainability?

In its most common use, the term sustainability is used as a short-hand term for environmental sustainability, which concerns human interactions with nature and technology. Often, sustainability simply relates the use of renewable, natural materials to the use of extracted, refined materials - usually favoring the former over the latter. Many non-industrial cultures, such as traditional Native American cultures, have practiced environmental sustain-ability as a normal, fundamental driver of their social practices. And any brief tour of a history museum reveals how ingenious pre-industrial societies of only two hundred years ago were in their use of natural materials such as plant and animal fibers, wood, stone, and bone.

Sustainability is now often defined as a goal, such as the goal of using technology and resources to "meet our current needs without preventing future generations from meeting their needs." (Some cite Thomas Jefferson as being one of the first modern Westerners to phrase the concept of sustainability in this way [1].) Sustainability's focus can be expanded to include the broader natural world, with its goal being to maintain our technological lifestyles while allowing all species of organisms to maintain their current numbers and life-styles as well.

The concept of sustainability is often commingled with issues about the health effects or damage to natural processes from the use of certain products or materials. Here, it is easier to identify what is unsustainable than to define what is sustainable. Any product

GENERAL INTRODUCTION 5

that potentially has negative effects on human (or animal or plant) health, or that accumulates as waste in the environment, could also be thought of as unsustainable. Or, sustainability is often tied to the issue of global climate change and energy use, accompanying argu-ments that current rates of greenhouse gas production and fossil fuel use are unsustainable.

Thus many people have many views about sustainability. Since success in sustainable manufacturing and marketing depends on having friendly, accessible markets and consumers, this book will take a broad view of sustainability, based on how it is widely defined by or thought of by experts and the public, rather than limit its definition in an academic or industry-preferred way. (And one might especially consider how a younger generation of consumers views issues of plastics and sustainability [consider Figure 1.1].)

Narrowing our scope to plastics, but otherwise still keep-ing a broad view of the issue, there are many arguments to be offered in favor of or against their sustainability. The arguments involve the real or theorized large-scale environmental impacts related to the fossil fuels on which most plastics are based. These fossil fuel reserves are dwindling or becoming harder to extract, resulting in higher prices and economic disruptions that even-tually will result from the unrestrained consumption of non-renewable resources. There is also damage anticipated from the global warming caused by greenhouse gas emissions, effects which are linked to the fossil-fuel-based economic infrastructure that keeps plastics cheap and disposable. And there are issues of waste and litter that the public is now more aware of, such as the Pacific Ocean "garbage patch" - a gyre composed of float-ing waste plastic and other products that has been reported on in recent years. Figure 1.2 illustrates the pressures of the above forces, including pressures from consumers and retailers and the increasing demand for plastics worldwide.

However, there are also sustainability arguments that often conflict with the goals of environmental sustainability. These emphasize another kind of sustainability: economic sustainability. Here sustainability is defined more as the ability of an economy or company to survive, long-term. For plastics-creating- and using-industries, economic sustainability typically requires avoiding higher costs - even when those costs come from using environ-mentally sustainable materials and processes. Questions about the quality of new sustainable materials, unresolved issues about

6 PLASTICS A N D SUSTAINABILITY

Figure 1.1 This piece of public art created by Michigan children shows the obvious concerns that young consumers have about sustainability. The "Trash Tree" sculpture was accompanied by a sign explaining that 80% of what Americans throw out is recyclable, though only a fraction of that is actually recycled. (Photo courtesy of S. Kalaj.)

GENERAL INTRODUCTION 7

processing these new materials, and consumers' interests in low prices all have the potential of overwhelming pro-environmental sustainability arguments. Meanwhile, a question remains as to whether business sustainability may eventually require proof that a company's products are also environmentally sustainable.

This book will attempt to balance and synthesize these views by demystifying some issues related to plastics and sustainability. It will take a fresh look at how renewable, bio-based plastics compare with traditional fossil-fuel-based materials. The book will not just focus on technical details and analyses, but also will consider con-sumer values, product requirements, market demands, laws and regulations, and basic practical issues. In addition, this book will try to find the ways in which economic sustainability and environ-mental sustainability can be linked by companies involved in the processing and use of plastics - especially those that are most often under scrutiny in terms of sustainability.

Higher-priced and/or depleted

fossil fuels

Plastics sustainability

efforts

Increasing demand for plastics worldwide

Consumer and retailer pressures

Regulatory pressures (e.g., global warming, pollution, etc.)

Figure 1.2 Large-scale social and natural forces are pressuring efforts toward making plastics and plastic products more sustainable and environmentally friendly.

8 PLASTICS AND SUSTAINABILITY

1.2 Facing the Contradictions of Plastics An honest assessment of plastics as being useful, important materials also requires admitting that plastic products' shapes, forms, compositions, uses, and material qualities are somewhat enigmatic or contradictory. Plastic products sometimes resemble objects from nature, although sometimes an alien, even science fiction form of nature. But normally they are not considered as being like anything that is natural; after all, plastic compositions are created by chemists and are mysterious to those uneducated in organic chemistry.

The term "plastics" is itself inadequate and misleading in that it refers to a wide range of materials. Some plastics are rubbery and some do not melt when heated; some are strengthened with glass fiber to become composites, while others are used in the form of simple films or foams. Certain plastic products are weak, cheap, and disposable; others are strong and durable - yet all are labeled simply as plastic.

Other contradictions below relate to plastics' place in our econ-omy and in our larger natural environment:

• Plastics are inexpensive... but their properties can be tailored for very high-value, engineering purposes.

• Plastics often have relatively simple chemical struc-tures... but they can be extremely resistant to pro-cesses of natural decay, guaranteeing their long-term persistence in the environment.

• Plastic products are lightweight... but millions of tons of them have been consumed and disposed of.

• Plastics are made from high-energy chemical feed-stock, becoming in essence "frozen fuel"... but plas-tic products and their inherent energy are commonly treated as waste for landfills, often after very brief lifetimes of use (unlike liquid or gaseous fuels, whose energy content is converted directly into heat or motion).

• Most waste plastics can be reprocessed at relatively low temperatures and energies.... but their relative low cost means their collection, separation, and recy-cling is often not cost-competitive with the production of new, virgin plastic.

GENERAL INTRODUCTION 9

• Different plastics are considered by the public as being very similar, and their differences are often hard to distinguish by eye... yet their tailored chem-istries, mechanical properties, and additives content often tie each plastic to a specific use (which also makes them harder to recycle and reuse in multiple applications).

Thus, even though plastic products are sophisticatedly designed and fabricated for even the simplest uses... most are still typically destined to become (very durable) trash.

At least one of these contradictions is directly focused on in this book: the use of valuable fossil fuels to create low-cost plastics. This is generally the case, though slowly in recent years, the existence of plastics is becoming less dependent on supplies of fossil fuels. More plastics are being made from renewable, biological sources. The growth rate of bio-based plastics is estimated to be 15-20% in 2011, and this growth is expected to continue at multiple times the rate of all plastics growth for the long term (with estimates varying from 12^10% annually) [2].

Bio-based polymers right now include the increasingly popu-lar corn ethanol-based polylactic acid (PLA). But the bio-based field may soon become dominated by conventional, well under-stood polymers, such as polyethylene and polypropylene, that are based on feedstock made from plant resources such as Brazilian sugarcane instead of fossil fuels. For example, Braskem SA in 2010 opened a plant in Brazil to make 400 million lb/yr of sugarcane-based polyethylene. The company has also dedicated $100 mil-lion for a 66-million lb/year bio-based polypropylene plant slated to begin operation by 2013 [3J. Although these materials will ini-tially be priced at a premium compared with fossil-fuel-based PE and PP, they stand as signs that the industry is indeed able to develop bio-based options for plastics.

As discussed in future chapters, many biological resources are being considered for creating bio-based plastics, ranging from food crops to bacteria, and from agricultural wastes to algae. As we will see, key questions about these bioresins concern their prop-erties and prices relative to those of fossil-fuel-based polymers -with many environmental, design, and social factors influencing the choices of manufacturers and consumers regarding bio- versus non-bio-based plastics.

10 PLASTICS AND SUSTAINABILITY

1.3 Plastics at Play in Consumer Lifestyles

Another plastics contradiction concerns consumers both in developed countries and, increasingly, in developing countries: Consumers have become incredibly dependent on plastic materi-als, even without understanding many of the details of their com-position or how they are manufactured.

There is something almost fantastic about plastic products -their shapes and colors, their textures and smooth forms. In the more exciting early days of plastics, people might have even been tempted to reference science fiction author Arthur C. Clarke's "Third Law" from 1962: "Any sufficiently advanced technology is indistinguishable from magic" [4]. However, now, after never really achieving the sensationalistic appeal of space flight, personal computers, or the cell phone, plastics are no longer new. The most common popular polymers have outlived their inventors, and any sense of plastics' magic or fascination for consumers is lost behind the banality of the many products they are used in. Rather, a more common question overheard today would be: "Do we really need plastics?"

Thus, ignorance, indifference, hostility, or ambivalence might be better terms for describing consumers' views of plastics today. These views have resulted in the easy demonization of certain forms of plastics, with a complete obliviousness about other potential problems associated with the ways we use all materials in indus-trialized society - metals, wood, and minerals, as well as plastics. Humans have consumed more of all these materials in the past 50 years than in all previous years combined - at increasing rates. And the vast majority of industrial materials are not based on naturally renewing resources, unlike in 1900, when over 40% of all materials used in the United States were based on forestry, agriculture, or other renewable industries [5]. These trends, coupled with incred-ible population growth, have definitely stressed the environment.

Plastics simply reflect these trends, though perhaps more promi-nently because they are used for so many visible, high-volume con-sumer items. In fact, the average consumer is the plastics industry's biggest supporter, whether he or she is aware of it or not. Between 1965 and 2005, the growth of plastic materials in the United States averaged close to 8% per year, currently with higher growth rates than that in India and China, as their populations' lifestyles become more industrialized [6]. There is no doubt that worldwide consumer

GENERAL INTRODUCTION 11

interest in and dependence on plastic-based products will continue for as long as it takes to develop equally versatile materials of another kind.

Consider the ubiquity or "everywhereness" of plastics by look-ing at a day in the life of an adult in an industrialized country. When she wakes up, the first thing she touches is probably plastic: an alarm clock. Walking across the (nylon) carpet to the bathroom, brushing her teeth, washing her hair, and using other personal care items, she encounters a variety of plastics. The clothing she dresses herself in likely contains some polyester or another syn-thetic fiber. Her juice bottle and cup is plastic, as is her coffeemaker. She wraps her lunch in a plastic film or bag and places it in a reus-able polymer-fiber sack. She drives to work in a car whose interior is almost completely covered in various polymer-based materials. She uses a coded plastic ID card to get into her workplace, grabs a (PET) bottle of water from the office refrigerator, and sits in front of a plastic-enclosed computer to spend the day tapping on plastic keys. Later, her evening at home or out on the town consists of similar contact points with plastics...

When looked at this way, the prevalence of plastics can be strik-ing. In fact, their importance seems directly proportional to the degree to which the consumer does not notice that he or she is actu-ally using a polymer-based product (especially in the case of bever-age bottles, toothbrushes, shoes, cell phones, food packaging, and car interiors). Even though today most plastic items are banal and uninteresting to the user/consumer, a day without their use would be unthinkable. Some people have tried to demonstrate that we can live our lives without plastics, but they have met only limited suc-cess, facing continual frustration from not ever being able to totally succeed.

1.4 Controversies Concerning Plastics: Recent Examples

Despite the consumer marketplace's apparent desire for products made from plastics, the materials have faced a history of intense public scrutiny. Some early commercial plastics formulations were dependent on ingredients, such as heavy metals, with negative human health or environmental effects. Most of these compositions have since been eliminated, but enough similar applications remain

12 PLASTICS AND SUSTAINABILITY

to keep public watchdogs skeptical about the health impacts of plastics. The scrutiny continues and will continue, given plastic products' new compositions, new forms, and complete integra-tion with everyday life. Acknowledging that this skepticism will continue is important for those who specialize in introducing new forms of plastics into the marketplace (even when these materials are based on natural, renewable resources).

Examples of plastics under scrutiny go back decades, and many controversies continue. Plastic additives, such as lead- and cadmium-based stabilizers and colorants were once heavily used in polyvinyl chloride (PVC) and other plastics. Since then, there has been general acknowledgement that there is potential harm in using heavy metal-based additives and coatings, resulting in a strong trend in the indus-try to eliminate them. For similar reasons, electronics manufacturers are avoiding plastics that include halogenated flame-retardant addi-tives, given concerns about the chemicals' environmental effects and persistence. And calls continue for eliminating the use of PVC itself, given its chlorine content and chlorinated-compound emissions dur-ing its manufacturing.

Another obvious example concerns many consumers' dislike of the use of expanded foam polystyrene products. The material is associated with possibly carcinogenic styrenic petrochemicals, ozone-layer-depleting blowing agents (once in common use), and its single-use, disposable, non-biodegradable nature. The feelings are intense enough that even the use of a Styrofoam coffee cup can draw someone's judgmental stare. A future alternative to achiev-ing the lightweight insulation properties of expanded PS may be bio-based plastic foams, though the negative image of plastic foam may remain [7].

Three other recent controversies related to plastics are of interest. These deserve more discussion below, and have been discussed fre-quently in the news media over the last few years. Unless they and some lesser-known issues can be resolved, these and other issues will likely keep plastics in general under intense public/governmental scrutiny - perhaps even transferring over to polymers made from renewable, bio-friendlier resources or processes.

1.4.1 PVC and Phthalate Plasticizers

Polyvinyl chloride, or simply PVC or "vinyl," has progressed down a rocky road from its original high mountaintop location of being