Preface

Chapter 7 **Synthesis and Characterization of Polymeric Material**

**MMT) under Microwave Irradiation 109** Rahmouni Abdelkader and Belbachir Mohammed

Chapter 8 **Biocomposites from Colombian Sugarcane Bagasse with**

**Properties 131**

**VI** Contents

Correa-Aguirre

**Polypropylene: Mechanical, Thermal and Viscoelastic**

**Consisting on Acrylamide Catalyzed by Maghnite (Algerian**

Miguel Ángel Hidalgo-Salazar, Fernando Luna-Vera and Juan Pablo

The old quote from the renowned psychiatrist C. G. Jung, who stated that "the whole is more than just the sum of its individual parts", can also be applied to the field of composite materials. As a matter of fact, the assembly and processing of basic materials, both of natural and/or artificial origin, can create innovative materials with completely novel properties and characteristics, which are often not expected *a priori* when studying the properties of the in‐ dividual starting materials.

Nowadays, we come across composite materials in almost all situations of our daily life. This may happen during shopping, when we buy food enveloped in multi-layer plastic composites and carry it home in carrier bags made of a composite material. Composites can accompany us when making sports in wintertime dressed in carbon fiber clothing, in our automobiles, where composites are used to reduce vehicle weight and to reduce CO2 emis‐ sions, or when we are grabbing our smartphone or tablet, which is most probably protected by an injection molded plastic-based composite. As another example, when I visited a scien‐ tific conference in France last year, coffee was offered in a cup consisting of an injection molded thermoplastic starch–bagasse composite material, which constitutes a sustainable al‐ ternative to petrochemical disposable cups. Moreover, every carpenter, architect, and han‐ dyman knows about the performance benefits of reinforced wood composites, widely used wood materials with high strength and dimensional stability with applications *inter alia* in construction and the furniture industry; hence, we live in houses where composite materials are omnipresent. In addition, reinforcing plastics with glass fibers offers options to generate high-performance glass fiber composites, which are applied in the construction sector, the leisure industry, as glass tapes on boats and ships, or in oil and gas lift systems. It might also be that, as I did this morning, the respected reader of this chapter even uses extra firm dog leashes made of glass fiber composites to walk his or her dog. As another example from the construction sector, concrete composite materials are used there, in which the relatively low tensile strength and ductility of concrete are compensated by the inclusion of reinforcement materials, which provides for enhanced tensile strength and/or ductility. Only during the last few years have concrete composites started to attract global attention also as the novel materials of choice to stabilize contaminated biological or soil materials; this application even provides the possibility to finally dispose materials contaminated by radionuclides in a safe and sustainable manner.

As a biotechnologist, I became personally fascinated by special new biocomposite materials, which were produced by our project partners about ten years ago. These biocomposites were based on a matrix of microbial polyhydroxyalkanoate bioplastics, which we produced in bioreactors by feeding bacteria with carbon-rich waste streams. Now, these bioplastics were processed by our project partners together with inexpensive renewable resources like

wood dust or lignin, which typically constitute waste materials without any special use. Pre‐ paring these composites definitely helped to overcome well-known shortcomings of native polyhydroxyalkanoate bioplastics, such as high brittleness and insufficient gas barrier per‐ formance. Designed composite films were thoroughly examined regarding their melting and crystallization behavior, mechanical and viscoelastic properties, thermo-oxidative stability, and gas permeability. It was shown that the composites exhibited outstanding mechanical and gas barrier properties and expedient thermos-oxidative stability, which pre-destines them for use in packing of easily perishable products such as food. Moreover, designing bio‐ composites is also a promising route to increase composability of polymeric materials; in the past, automotive parts, or even machine components were already developed consisting of a matrix of a biopolymer and abundantly available filler materials such as bagasse. After the product´s life span, it can be disposed of with a clear conscience on the compost heap. A solution for the current plastic pollution problem!

a new material to outperform established products in terms of material quality, economics of its production, and sustainability aspects. Nowadays, a range of different physical and chemical techniques for analysis and characterization of new composite materials are availa‐

Writing this brief preface, it is an outstanding pleasure for me to span the bridge between the individual chapters included in this fascinating book project. Leading scientists from di‐ verse academic disciplines provide insights into their particular activities and knowledge related to the composite field, with special emphasis on novel and established tools to assess

Office of Research Management and Service, c/o Institute of Chemistry

**Hosam El-Din M. Saleh, Ph.D.** Atomic Energy Authority Radioisotope Department Nuclear Research Center

Giza, Egypt

Preface IX

**Martin Koller** University of Graz

Graz, Austria

ble, and comprehensively presented in the book at hand.

Enjoy reading!

the quality and potential of these future-oriented hybrid materials.

Currently, we witness a tremendously dynamic development in designing and processing of composites all over the world. For example, advanced composite materials, which contain high strength fibers occupying a large volume of a polymer matrix, are developed globally in order to produce materials with enhanced elasticity and strength along the direction of the reinforcing fiber. Further, such advanced composites display expedient dimensional sta‐ bility, temperature, and chemical resistance, flex performance, and are relatively easy to be processed by well-established processing technologies. Apart from established processing methods such as melt extrusion, injection molding, melt-spinning, or solvent casting, we get more and more familiar with new emerging processing techniques such as additive manu‐ facturing (3D-printing), electrospinning, or computer-aided wet spinning to produce mar‐ ketable products made of composite materials. To an increasing extent, such products find use also in the biomedical field such as for production of implants or artificial joints, or for development of scaffolds for enhanced attachment of cell cultures, e.g., for stem cell cultiva‐ tion.

Not only are such composites designed to trigger fundamental physical material properties of a basic material such as density, breakage, or crystallinity; beyond that, to an increasing ex‐ tent, nanotechnology enters the field of composite development; "small is beautiful" is also valid for new composites! These nano-technological approaches allow the design of complete‐ ly new, smart materials with properties fine-tuned to special customer demands. Depending on the type, size, and content of applied nano-fillers, which might be cellulose nano-whiskers, glass-, silica-, or metal nanoparticles, carbon nanotubes, and many more, it is possible to markedly change and fine-tune the mechanical, electrical, electrochemical, thermal, optical, hydrophilic, piezoelectrical, and even catalytic properties of the matrix materials.

However, it is by far no trivial task to develop a new composite material, which exactly matches the performance expectations set by a customer. As Albert Einstein said: "Who nev‐ er failed never tried out something new!" Hence, such R&D developments *en route* towards a smart composite material are typically cumbersome, involve steps backwards, and take time. In this context, for the development of a new composite material, the synergistic knowledge from experts of different scientific disciplines is required, which calls for the in‐ put from chemistry, physics, engineering, and environmental sciences. Especially the de‐ tailed characterization of new composite materials is the *conditio sine qua non* needed to assess the performance and applicability of a new composite material. As shown in this book, it is pivotal to define quality and performance benchmarks, which have to be meet by

a new material to outperform established products in terms of material quality, economics of its production, and sustainability aspects. Nowadays, a range of different physical and chemical techniques for analysis and characterization of new composite materials are availa‐ ble, and comprehensively presented in the book at hand.

Writing this brief preface, it is an outstanding pleasure for me to span the bridge between the individual chapters included in this fascinating book project. Leading scientists from di‐ verse academic disciplines provide insights into their particular activities and knowledge related to the composite field, with special emphasis on novel and established tools to assess the quality and potential of these future-oriented hybrid materials.

Enjoy reading!

wood dust or lignin, which typically constitute waste materials without any special use. Pre‐ paring these composites definitely helped to overcome well-known shortcomings of native polyhydroxyalkanoate bioplastics, such as high brittleness and insufficient gas barrier per‐ formance. Designed composite films were thoroughly examined regarding their melting and crystallization behavior, mechanical and viscoelastic properties, thermo-oxidative stability, and gas permeability. It was shown that the composites exhibited outstanding mechanical and gas barrier properties and expedient thermos-oxidative stability, which pre-destines them for use in packing of easily perishable products such as food. Moreover, designing bio‐ composites is also a promising route to increase composability of polymeric materials; in the past, automotive parts, or even machine components were already developed consisting of a matrix of a biopolymer and abundantly available filler materials such as bagasse. After the product´s life span, it can be disposed of with a clear conscience on the compost heap. A

Currently, we witness a tremendously dynamic development in designing and processing of composites all over the world. For example, advanced composite materials, which contain high strength fibers occupying a large volume of a polymer matrix, are developed globally in order to produce materials with enhanced elasticity and strength along the direction of the reinforcing fiber. Further, such advanced composites display expedient dimensional sta‐ bility, temperature, and chemical resistance, flex performance, and are relatively easy to be processed by well-established processing technologies. Apart from established processing methods such as melt extrusion, injection molding, melt-spinning, or solvent casting, we get more and more familiar with new emerging processing techniques such as additive manu‐ facturing (3D-printing), electrospinning, or computer-aided wet spinning to produce mar‐ ketable products made of composite materials. To an increasing extent, such products find use also in the biomedical field such as for production of implants or artificial joints, or for development of scaffolds for enhanced attachment of cell cultures, e.g., for stem cell cultiva‐

Not only are such composites designed to trigger fundamental physical material properties of a basic material such as density, breakage, or crystallinity; beyond that, to an increasing ex‐ tent, nanotechnology enters the field of composite development; "small is beautiful" is also valid for new composites! These nano-technological approaches allow the design of complete‐ ly new, smart materials with properties fine-tuned to special customer demands. Depending on the type, size, and content of applied nano-fillers, which might be cellulose nano-whiskers, glass-, silica-, or metal nanoparticles, carbon nanotubes, and many more, it is possible to markedly change and fine-tune the mechanical, electrical, electrochemical, thermal, optical,

However, it is by far no trivial task to develop a new composite material, which exactly matches the performance expectations set by a customer. As Albert Einstein said: "Who nev‐ er failed never tried out something new!" Hence, such R&D developments *en route* towards a smart composite material are typically cumbersome, involve steps backwards, and take time. In this context, for the development of a new composite material, the synergistic knowledge from experts of different scientific disciplines is required, which calls for the in‐ put from chemistry, physics, engineering, and environmental sciences. Especially the de‐ tailed characterization of new composite materials is the *conditio sine qua non* needed to assess the performance and applicability of a new composite material. As shown in this book, it is pivotal to define quality and performance benchmarks, which have to be meet by

hydrophilic, piezoelectrical, and even catalytic properties of the matrix materials.

solution for the current plastic pollution problem!

tion.

VIII Preface
