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Multifunctional Polymer Chemistry: Sustainable Synthetic Procedures

Prem Shankar Mishra1*, Rakhi Mishra2, Kabikant Chaurasiya1 and Tanya Gupta1

1Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida, Uttar Pradesh, India

2Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, Uttar Pradesh, India

Abstract

Naturally occurring polymers such as DNA strands and polypropylene, which are widely used as plastic worldwide, are examples of polymers that surround us. Due to the required performance and poor recycling rates of polymers, there is a continuing demand for virgin polymers; nonetheless, this exacerbates serious challenges associated with the plastics sector, such as waste creation and greenhouse emissions. It is necessary to assess the sustainability effects of bio-based polymers to retain their biodegradation potential while maximizing their utilization in the functional use stage. The several green chemistry-based synthetic techniques used to produce multifunctional polymers are the main subject of this study. This chapter also includes information on the applications, challenges, and future possibilities of multifunctional polymers.

Keywords: Chemoenzymatic, polypropylene, controlled radical polymerization, microbial synthesis

1.1 Introduction

Sustainability is the responsible use of natural resources, preservation of the environment, waste minimization, and avoidance of dangerous materials so that future human generations can continue to live a decent standard of living on Earth (Figure 1.1) [1]. These days, sustainability and green chemistry are the primary strategies due to growing public knowledge of environmental deterioration, climate change, and the earth's diminishing resources. In order to be achieved by 2030, the United Nations adopted 17 sustainable development goals (SDGs) in 2015. Since polymers are ubiquitous, they are essential to achieving these objectives [2].

Another way to think of sustainability as a business strategy is to maximize the positive effects of an organization on the environment, communities, economy, and society [3].

Figure 1.1 Impact of sustainability on different aspects.

Businesses are starting to see the benefits of sustainability, including increased exposure and lower manufacturing costs, energy use, risks, and dangers [4]. Sustainability can take on a variety of shapes depending on the enterprises involved, such as the following:

• The environmentally benign and non-hazardous production of commercial items using resources derived from agriculture.
• The use of "natural" components in commercial goods, particularly in applications related to food, cosmetics, and personal hygiene.
• The enhancement of existing industrial processes by reduction of non-recyclable plastic usage, reduction of needless byproducts, development of a greener supply chain, and/or reduction of carbon footprint.
• Enhancing the environmental, health, and safety aspects of existing product lines through prudent management [5, 6].

Today, disposing of plastic garbage is a major environmental issue since plastics are being produced in large quantities and are being used in more areas of our daily lives [7]. As a result, these problems contribute to the rising threat of the warming planet brought on by carbon dioxide emissions caused by burning conventional, non-biodegradable polymers, such as polyethylene, polypropylene, and polyvinyl chloride [8].

Polymers can be divided into two categories: natural polymers and synthetic polymers.

Biocatalysts, often enzymes, are invariably engaged in in vivo processes that produce natural polymers in the natural world. All living things, including humans, animals, and plants, include natural polymers. Among the natural polymers are lignocellulose, starch, protein, DNA, RNA, and polyhydroxyalkanoates (PHAs). Natural polymers often have clearly defined structures, while some, like lignocellulose, are an exception [9].

The most popular way to create synthetic polymers is to polymerize compounds with simple structures derived from petroleum. Synthetic polymer preparation often involves the use of chemical catalysts, particularly metal catalysts. The growth of the petrochemical industry, the simultaneous availability of cheap petroleum oils, the development of well-established and sophisticated polymerization techniques, and the availability of cheap petroleum oils have led to the development of many synthetic polymers, including phenol-formaldehyde resins, polyolefins, polyesters, polyvinyl chloride, polystyrene, and polyamides. Plastics, a broad category of synthetic polymers, gained popularity early in the 20th century and are today widely found in many different items, including textile fibers, films, bags, bottles, and cartons [10].

Biodegradable polymers are materials that, after a short time of use and under controlled circumstances, disintegrate into components that can be readily disposed of [11]. They can be made from a variety of wastes or bioresources, such as food, animal, and agro-waste waste, as well as cellulose and starch, Businesses are concentrating on generating bioplastics produced from renewable resources since they are often more cost-effective than those obtained from microbiological resources [12].

Using biodegradable polymers helps the environment by lowering the emissions of carbon dioxide, which contribute to global warming, promoting biodegradation, and regenerating raw resources [13]. Microorganisms such as bacteria and fungi can ingest bio-degradable polymers, which subsequently undergo degradation into H2O, CO2, and methane. The substance's composition has an impact on the biodegradation process. Polymer shape, structure, molecular weight, and exposure to radiation and chemicals are some of the elements that affect how quickly a polymer degrades [14].

The market for biodegradable plastics is quite promising. However, as selective bio-waste collection grows, they must be created simultaneously with a comprehensive analysis and worldwide integration with organic waste management and end-of-life treatment techniques. One advantage of biodegradable plastics is that they may be naturally decomposed at the end of their lives through processes like anaerobic digestion or composting. Biodegradable plastic composting is widely acknowledged and well-documented worldwide [14]. This chapter describes multifunctional polymers and the many environmentally friendly synthetic processes that are employed to create them using green chemistry. Details on the uses of multifunctional polymers, as well as their prospects and difficulties, are also included in this chapter.

1.1.1 Multifunctional Polymers

Materials known as polymer composites are created by adding fibers or other appropriate reinforcement to the polymer matrix [15, 16]. These are often described in various ways. The kind of matrix might be either natural or synthetic, depending on the intended use. Synthetic polymers are utilized to provide the matrix for most applications; biopolymers have only recently been employed in this capacity [17]. Fibers, either natural (like coir, bagasse, pine needles, hemp, flax, and sisal) or synthetic (such as carbon and glass), are the most common types of reinforcing materials. Both the polymer matrix and the reinforcement have been found to have a substantial impact on the overall physicochemical properties of the composites [18].

Due to the growing potential for polymer multifunctional application, researchers from many domains have recently focused a great deal of emphasis on two related essential topics: biopolymers and biomaterials (Figure 1.2) [19]. These days, biopolymers are a hot issue because of their prospective uses in the food, pharmaceutical, textile, medical, and other industries as well as in addressing the problems associated with rising environmental contamination [20].

The ecosystem has already suffered greatly from the careless use of easily accessible and reasonably priced synthetic plastic, and these materials are now posing a major danger to all life on Earth [21, 22]. Because synthetic plastic is used so extensively in everyday products, it is becoming a severe hazard to human health. In this regard, bio-based, sustainable, and biodegradable polymers hold great promise as a quick replacement for synthetic polymers generated from petrochemicals. To create bioplastics, a variety of biopolymers, including polysaccharides, proteins, and their mixtures, are frequently employed. The characteristics of biopolymer-based polymers are similar to those of synthetic ones [23, 24].

The addition of functional components such as nanomaterials, essential oils, phytochemicals, and bioactive components further enhances the physical and functional properties of the biopolymer-based materials. It has been demonstrated that one practical way to alter the mechanical characteristics of the polymer matrix is by adding fillers, as well as imparting thermal and electrical conductivity and increasing thermal resistance concerning glass transition and degradation temperatures. While the potential of biomaterials and biopolymers to create sustainable materials is great, there are still several issues that need to be resolved before further development can begin. These materials are more...