Advanced Functional Polymers

Advanced functional polymers represent the class of materials with unique properties and applications in a variety of fields. This book covers recent advances in the synthesis and applications of advanced functional polymers including smart polymers, shape memory polymers, self-healing polymers, biopolymers, etc. The book also highlights the applications of these functional polymers in advanced functional polymers in various fields including lamellar membranes, paints, coatings, composite implants, zero-G applications, etc. The characterisation and recycling techniques for these polymers and composites are also discussed in the book.

This chapter covers the stereospecific polymerization of different types of polymers that can be stereo regulated. The monomers of stereospecific polymers have side groups attached to the backbone of the polymer and their preparation involves complex catalytic systems. The characteristics of these polymers holding stereochemical isomerism in their main chain are mainly affected by the stereochemical structure. Up to now the control of stereochemistry to achieve the required properties is not fully realized. This chapter provides a brief overview related to the stereochemistry of polymers with mechanical, thermal, and electrical properties.

This book chapter gives a comprehensive review of two-dimensional (2D) nanomaterials that provide tremendous potential for separation applications. By using 2D nanomaterials as a building block, various types of lamellar membranes are actively investigated. In lamellar membrane, the mass transport occurs through the inherent interplanar spacing of the nanomaterials and the nanochannels generated during the fabrication of lamellar membranes. However, the trade-off between permeability and selectivity in membranes is inevitable. Different strategies such as interlayer channel aperture, membrane nanopores, and appropriate functionalization can bridge this trade-off. Various routes for preparing lamellar membranes including 2D nanosheet synthesis strategies, assembling techniques, mechanisms involved in transportation, and regulation of nanochannels are discussed in detail.

Polymeric coatings are applied on surfaces of metal, wood, plastics, and other materials to offer protection, decoration, and specific functionality. Polymeric coating technology is one of the old fields; still, it requires further maturity for perfection. The key trends in polymeric coatings include the production of environment friendly coatings, improving the functionality of existing coatings, and the development of smart coatings with multifunctional properties. Polymeric coatings with such properties are not feasible by conventional formulation and synthesis techniques. Therefore, modern technologies such as controllable graft polymerization, free‐radical polymerization, and micro‐emulsion polymerization are employed for these coatings. Moreover, the use of novel modified methods, functional pigments and the construction of nano- and micro-surfaces can produce polymeric coatings with multifunctional and enhanced properties. This chapter emphasizes traditional and advanced functional polymer-based coatings.

This chapter covers the smart polymers and composites used for various applications like fuel cells, bio-medical applications, temperature and pH-responsive polymers, membranes, and nanocomposites. Smart polymers and composite popularity is increasing for various reasons like the polymers can be designed as environmentally friendly, stimuli-responsive like green polymers, smart polymeric coatings, biopolymers for cleaning dyes from water at the end of adsorbent, and energy efficient as a fuel cell and smart filtration process as a membrane. Other than conventional membrane, stimuli-responsive membrane materials are also discussed. The use of biocompatible polymer and biodegradable polymer materials for various applications is also included in the chapter.

The research in the field of self-healing elastomers (SHE) has resulted in different complex structures with various healing strategies (hydrogen bonds, covalent and non-covalent interactions and combinations of both). Elastomers with good mechanical performance and healing efficiency typically do not exist, as self-healing mechanism limits the mechanical properties. To get optimum mechanical and healing properties, using a combination of different mechanisms is emerging as a possible solution in SHEs. This chapter, mainly focused on SHEs, in which covalent bonds in combination with non-covalent interactions provide the best balance between repairability and mechanical performance. The applications of SHE include sensors, controlled drug release, coatings, actuators, railway components, hoses, seals, gaskets, and tires used in high-performance applications.

The utilization of non-biodegradable disposable plastic has increased exponentially due to its lightweight and user-friendliness. Nonetheless, the non-biodegradable plastic waste produced by disposable plastics increases the environmental carbon footprint. The utilization of biodegradable plastics is one solution to mitigate the environmental pollution problem. Currently, only 1% of 300 million tons of plastic produced annually is biodegradable. Biodegradable plastics are obtained from both natural and synthetic resources. Due to their lower strength, natural-origin biodegradable plastics are only used in a few applications. For a large number of applications, the mechanical strength and other properties of synthetic-origin biodegradable plastics can be engineered. This chapter covers the biodegradable plastics of synthetic-origin including aliphatic polyesters, aromatic copolymers, vinyl polymers, and biodegradable polyurethanes. Biodegradation (both biotic and abiotic) in synthetic-origin biodegradable polymers has been discussed followed by the classification and degradation tendencies in synthetic-origin biodegradable plastics.

Long bone fractures are treated with internal fixation prostheses such as screws, pins, intramedullary nails, and bone plates, depending on the type and nature of the fracture. Different prostheses exhibit dissimilar fixation constructs which are vital for callus generation and fracture bridging. Metallic implants have a significant mismatch with bone mechanical properties and create stress concentrations at the plate, which results in stress shielding. This phenomenon impedes load transmission at the fracture site, which can lead to non-union, bone mass loss, delayed healing, refracture, and construct failure. Flexible fiber-reinforced composite prostheses respond to biological friendly healing (secondary healing) and promote callus generation and soft tissue maturation and can provide solutions to problems. These polymer implants promote bioactivity around the implant. Further, the polymer composites biomechanical properties can be tuned easily by adding the functional powders into matrix and changing the type or direction of reinforcement fibers. The performance of these composites from the published work according to different materials is discussed. This chapter concludes that the bioinspired polymer composites have the potential to replace traditional metallic implants for orthopedic applications.

The current chapter focuses on the functional polymer and composite materials used for zero gravity applications. It discusses the various structures that are used in zero gravity (zero-G) and the material requirements for these structures. A structure in zero-G experiences harsh environmental conditions including the damaging effects of high vacuum, atomic oxygen (ATOX), radiations (ultraviolet and ionizing radiation), micrometeorites (i.e., space debris), and thermal cycling. The commonly used materials for zero gravity include polymers for thermal blankets or electronic components, adhesives, polymer aerogels, shape memory polymers, fiber reinforced composite materials, fiber metal laminates, protective coatings against atomic oxygen exposure and lunar dust adhesion, etc. All these materials have been detailed in this chapter and concluded with future trends in the domain.

Polymers and their composites are preferred over conventional materials like steel, copper, and aluminum due to their high corrosion resistance, flexibility, ease of processability, and lightweight. Various analytical techniques have been used for the characterization of polymers and their composites as a function of either time or temperature. Morphological structure, molecular weight, analysis of monomer, solvent residue, the composition of the copolymer, and interfacial interfaces of polymeric systems are some of the advanced properties of polymers and composites. The current chapter covers some of the advanced characterizations techniques like Dynamic Mechanical Analysis (DMA), Thermomechanical Analysis (TMA), Atomic Force Microscopy (AFM), 4-Probe technique, Inverse Gas Chromatography (IGC), and Gel Permeation Chromatography (GPC). The above-mentioned techniques are used to determine various properties of advanced polymers like their response to heat, stress, electrical resistance, molecular weight, etc.

This chapter includes an introduction to polymers and their recycling methods. Recycling is the most suitable alternative to control and avoid the accumulation of plastic waste in the environment. Polymers are compounded for improved performance which makes them difficult to reuse and/or recycle. Polymers can be categorised into two major groups: thermosetting and thermoplastic. The production and use of thermoplastic polymers are much higher in quantity as compared to thermosets globally. Therefore, the recycling techniques for thermoplastics are of major importance. Primary, secondary and tertiary recycling techniques for thermoplastics are discussed in this chapter. Waste management for thermosets is mostly unavoidable and important from an environmental point of view. Thermal, mechanical, chemical waste recycling techniques for thermosets and the inherent recyclability of thermoset polymers are focused in this chapter. The potential applications of recycled thermoplastics and thermosets are also discussed.