Green Chemistry for Surface Coatings, Inks and Adhesives

Sustainable Applications

Rainer Höfer, Avtar Singh Matharu, Zhanrong Zhang

• Publisher: Royal Society of Chemistry
• Year: 2019
• Print ISBN: 9781782629948
• eBook ISBN: 9781788018005
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Environmental Science

Many modern surface coatings and adhesives are derived from fossil feedstocks. With fossil fuels becoming more polluting and expensive to extract as supplies dwindle, industry is turning increasingly to nature, mimicking natural solutions using renewable raw materials and employing new technologies.

Highlighting sustainable technologies and applications of renewable raw materials within the framework of green and sustainable chemistry, circular economy and resource efficiency, this book provides a cradle-to-cradle perspective. From potential feedstocks to recycling/reuse opportunities and the de-manufacture of adhesives and solvents, green chemistry principles are applied to all aspects of surface coating, printing, adhesive and sealant manufacture.

This book is ideal for students, researchers and industrialists working in green sustainable chemistry, industrial coatings, adhesives, inks and printing technologies.

CHAPTER 1

Green Chemistry Principles and Global Drivers for Sustainability – An Introduction

Avtar S. Matharu^* and Kadambari Lokesh

University of York, Green Chemistry Centre of Excellence, Department of Chemistry, York YO10 5DD, England, UK
^*E-mail:[email protected]

This chapter by way of an introduction gives a big picture overview of the importance of adhesives and sealants and the need for green chemistry. Global drivers for change are considered, which are inter-related to our need for materials but also the challenges of ‘doing the right thing’ for a sustainable 21st Century. The biobased adhesives and sealants market is growing commensurate with the need for more materials. More publications are now appearing in the literature with respect to biobased and renewable resources in the context of green chemistry. The latter is explored in this chapter, which defines the 12 principles and discusses green metrics and solvents. Green chemistry is linked to sustainability and the combination of the two often leads to life cycle assessment or analysis.

1.1 Introduction: Drivers for Change

“We need to engineer ourselves out of a problem”

Chemistry, chemical engineering and allied subjects have given modern-day society unprecedented access to chemicals, materials (articles) and energy predominantly derived from crude oil. Over the last forty years, global material use has tripled, with annual global extraction of materials growing from 22 billion tonnes (1970) to 70 billion tonnes (2010). As the global population is set to increase from 7 billion (2018) to 9 billion (2050), we will require about 180 billion tonnes of materials annually by 2050.^1,2 Adhesives and sealants have played a prominent role in the success of these materials. Significantly, many of these materials have been designed, engineered and manufactured to be long-lasting, one use only and not designed for re-use or recycling. They operate within the principles of a linear economy that takes, makes, uses and abuses materials, which at end of life (EoL) end up as waste, i.e., cradle to grave. Often, the success or longevity of many petroleum-derived adhesives and sealants restricts disassembly, recycling and re-use at EoL thus adding to an increasing environmental waste burden. We have engineered ourselves into a problem based on an over-reliance on a relatively abundant, historical feedstock that has brought economic wealth but now even bigger environmental and social challenges.

Crude oil is a finite resource. In 2017, global proved oil reserves, i.e., the estimated quantities of oil that geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under current economic and operating conditions, were 1696.6 billion barrels. Based at this level, only 50.2 years of global production are left.³ We need to decouple human development efforts from ever-increasing natural resource use, energy demand, emissions and waste. Thus, the need for alternative sources of sustainable and renewable energy, materials and chemicals is immediate. A move towards more green adhesives and sealants derived from renewable resources, which use less or non-toxic additives, low VOCs (if any), low energy, and minimise waste both during manufacture and at EoL, is a positive step forward. The adhesives and sealants industry has been moving in this direction for many years through solvent-free liquid, 100% solid and waterborne formulations. We need to engineer ourselves out of a problem for the future of a sustainable 21st Century. Not to forget that often enough, adhesive bonding in itself is, from a sustainability point of view, advantageous over other bonding techniques, be it welding and soldering, be it “classic” mechanical assembly like bolting, screwing, and nailing or others.⁴

1.2 Biobased Markets and Trends⁵

The adhesives and sealants industry is moving towards becoming green. Historically, and today, many adhesives and sealants have been renewable or biobased resource-derived, for example, carbohydrates, tree resins, lignins, unsaturated oils and proteins. In 2017, globally, two industry sectors were dominant users of biobased adhesives and sealants (Figure 1.1), namely building and construction (250.77 kilo tons), and paper, packaging and board (356.56 kilo tons). Within the confines of the listed industrial sectors shown in Figure 1.1, over a 5 year period from 2018, the forecast predicts volume to increase at 4.49% compound annual growth rate (CAGR) reaching 1293.96 kilo tons by 2023.

Figure 1.1Global bio-based adhesives & sealants market by end-user industry (in Kilo Tons).

Further analysis of available data on global trends by geographical region (Figure 1.2) shows that in 2017 the global biobased adhesives and sealants market reached 996.53 kilo tons with Europe (357.29 kilo tons) dominating closely followed by North America (304.91 kilo tons) and Asia-Pacific (269.22 kilo tons).

Figure 1.2Global bio-based adhesives & sealants market (in Kilo Tons).

Importantly, the distribution (spread) and type of biobased raw materials are shown in Figure 1.3. Soy and starch-based raw materials for adhesives and sealants are dominant in this respect, occupying nearly 50% (565.39 kilo tons) market share of the total (996.53 kilo tons) in 2017, with the others category comprising natural rubber latex, protein adhesives, polylactic acid and polyhydroxyalkanoates in third place (252.32 kilo tons). Lignin-based adhesives⁶ compared to the other categories are relatively low volume (63.82 kilo tons).

Figure 1.3Global bio-based raw materials adhesives & sealants market (in Kilo Tons). Others* include natural rubber latex, protein adhesives, polylactic acid, and polyhydroxyalkanoates.

Despite these positive trends, the vast majority of adhesives and sealants are still petroleum-derived (synthetic), associated with environmental pollution, and complex formulations/products comprising volatile organic solvents (VOCs). The latter should not be ignored because their volume is cleaning, and priming of substrates prior to adhesion can be significant.

1.3 Circular Economy, SDGs, Waste, and Legislation

In 2015, the United Nations (UN) recognised the importance of sustainability in their report: ‘Transforming our World: the 2030 Agenda for Sustainable Development,’ which aims to protect the planet, people, alleviate poverty and enhance peace.^7,8 Seventeen Sustainable Development Goals (SDGs, Table 1.1) were actioned from this report with each goal further subdivided into several specific ‘targets’. The SDGs comprehensively address the natural resource underpinnings of economic growth and human development across all aspects of resource use. For example, SDG 12 is of particular relevance to this chapter, as it deals with sustainable consumption patterns and production aiming to reduce or minimize the impact of waste, improve climate change and foster circular rather than linear economies by ‘doing more with less’, i.e., a more resource-efficient society. Specifically: Target 2: By 2030, achieve the sustainable management and efficient use of natural resources, and Target 5: By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse.

Table 1.1UN sustainable development goals (SDGs)

SDG	Overview and action
1	No poverty:
	End poverty in all its forms everywhere.
2	Zero hunger:
	End hunger, achieve food security and improved nutrition and promote sustainable agriculture.
3	Good health and well-being:
	Ensure healthy lives and promote well-being for all at all ages.
4	Quality education:
	Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all.
5	Gender equality:
	Achieve gender equality and empower all women and girls.
6	Clean water and sanitation:
	Ensure availability and sustainable management of water and sanitation for all.
7	Affordable and clean energy:
	Ensure access to affordable, reliable, sustainable and modern energy for all.
8	Decent work and economic growth:
	Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all.
9	Industry, innovation and infrastructure
	Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation.
10	Reduced inequality:
	Reduce inequality within and among countries.
11	Sustainable cities and communities:
	Make cities and human settlements inclusive, safe, resilient and sustainable.
12	Responsible consumption & production:
	Ensure sustainabl...

Table of contents

• Cover
• halftitle
• Series Editor
• Title
• Copyright
• Preface
• Contents
• Chapter 1 Green Chemistry Principles and Global Drivers for Sustainability – An Introduction
• Chapter 2 Green Solubility for Coatings and Adhesives
• Section 1: Natural Adhesive and Surface Coating Concepts
• Section 2: Biobased Binders and Additives
• Section 3: Sustainable Adhesive and Surface Coating Technologies
• Subjected Index