The invention of plastic can be said to be one of the most significant inventions that has transformed human life. It continues to play an indispensable role in food, clothing, housing, transportation, education, entertainment, and even in defense, aerospace, and healthcare. However, as environmental pollution continues to escalate, plastics are increasingly estranged from the concept of environmental sustainability. The environmental problems caused by plastics are under constant scrutiny, and driven by media and social media, plastics have become the most culprit. However, materials themselves are neither good nor bad; it's how people use them that matters. When considering the environmental sustainability benefits of materials, plastics possess inherent advantages. However, the effective and proper use of plastics is a crucial aspect that we must address. What is "material sustainability"? The concept of sustainable materials can be traced back to the first International Conference on Materials Science in 1988. Sustainable materials are broadly defined as "materials that minimize and minimize harm to the global environment and human health during the stages of raw material sourcing, product manufacturing, use, and post-use recycling." The Center for Sustainable Materials at Rutgers University, New Jersey, also points out that "sustainable materials are those used throughout our consumer market and industrial processes that can be mass-produced without depleting non-renewable resources or disrupting the stable balance of the environment and natural resource systems." This demonstrates the close relationship between material application and development and the environment. Understanding material characteristics and applications, and assessing their environmental impact, is crucial for effectively improving environmental quality and sustainability. Sustainable Development of Plastics: Plastics are indispensable materials in modern life. Their excellent shaping ability, lightweight nature, and ease of mass production make them widely used in various fields. With technological advancements, in addition to plastic raw materials produced by the petrochemical industry, they can now also be produced from non-petrochemical systems, extracted from natural plants and animals. These plastics are called bioplastics. For example, PET materials can be partially derived from petroleum, while other parts can be extracted from natural plants and animals. Their physical properties are the same; the difference lies in the production process. Compared to traditional petrochemical plastics, bioplastics have advantages in both energy consumption and carbon emissions. As shown in the "Plastics Classification Cross Diagram" (Figure 1), plastics can be further divided into biodegradable and non-biodegradable types based on their biodegradability. Traditional PP plastics and biodegradable PLA plastics each have their own representative characteristics. However, due to their material properties, biodegradable and non-biodegradable plastics have different recycling and reuse pathways. Under a good circular system, both can extend the material life cycle for reuse and remanufacturing in high-quality applications. The concept of the "Circular Economy System" (Figure 2) has changed the traditional linear economy (production → use → disposal → incineration) and replaced it with a circular economy model that changes the product life cycle. In the early stages of product design, we should consider how to introduce the next cycle at the end of the product's life cycle. Depending on the material selected, we can implement "industrial cycle" or "biological cycle" models to transform industrial waste into useful nutrients and continuously recycle and reuse limited resources. However, the concept of a "circular economy system" provides a good solution for plastic products. Leveraging the excellent plasticity, processability, and innovative biodegradability of plastic materials, traditional plastics follow an "industrial cycle" model, extending their product lifecycle through repair, reuse, remanufacturing, and recycling. Biodegradable plastics, on the other hand, follow a "biological cycle" model, returning to the earth to nourish the land. While the concept of a "circular economy system" offers a good solution for product production and disposal, without the introduction of "green design" thinking—simplifying product structure design, facilitating component disassembly, and lightweighting—it will be difficult to realize a circular economy model. Adopting the 4R green design principles from the initial product design stage—Reduce in material usage; Reuse in component usage, reusing reusable components to reduce waste; Recycle in product disposal, envisioning future recycling methods; and Regeneration in product reuse, considering whether recycled products can be used to produce high-value products again—following the 4R green design principles and combining them with appropriate sustainable materials will accelerate the development of a circular economy. A book on sustainable materials, published as part of the 2019 Green Little Giant Project, is a circular economy book titled "Corporate Sustainability Starts with Materials - A Key Guide to Sustainable Plastic Materials." Through analysis of the sustainability of plastic materials, expert columns, explanations of the characteristics of traditional and biodegradable plastics, and case studies from relevant manufacturers, this book compiles the application of sustainable plastic materials, aiming to provide related businesses and manufacturers with a guide for future sustainable product development. The book references the United Nations Sustainable Development Goals (SDGs) and integrates international green issues, focusing on sustainable materials and green design. It is hoped that through the promotion and value dissemination of this book, seeds will be sown in the industry, and through the fermentation and practice of domestic SMEs, enabling them to consider the sustainability and environmental impact of materials from the source of product development. This will help various industries thrive in the pulse of the circular economy, establish themselves in Taiwan, and look towards the international stage, creating more green little giants. Source: SME Green Environmental Protection Information Network
