Preface

Over the last few decades, incorporation of fillers in composites has acquired an important place in commercial applications. Initially, these fillers were generally composed of cheap, easily available diluents and were entitled as fillers. However, their ability to tailor the properties of final material has burgeoned and that's why these filler-based composites find different applications in today's fast-growing world. Various organic and inorganic fillers are utilized in composites to enhance the properties and simultaneously reduce the cost of materials. Particulate fillers are responsible for delivering many advantages, namely cost reduction, improved processing, density control, thermal properties, electrical properties, flame retardancy, enhanced mechanical properties, and wear resistance.

This book embraces all the chapters that are concerned with the effect of incorporating different fillers or particulates on fabricated composites. It delivers a comprehensive study associated with the sections of material science, polymer technology, anisotropic elasticity phenomena, fracture mechanics, applied mechanics, material synthesis, mechanical and thermomechanical characteristics, tribological behavior, etc.

Significant research efforts all around the world are continuing to explore the properties of composite materials. Researchers are collectively focusing their efforts on the use of particulate fillers in composites for miscellaneous applications. To ensure a sustainable future, the use of fillers is the best solution to improve the properties and reduce the ultimate cost of materials. This book is solely focused on fillers, and some of the important topics include but are not limited to synthesis, characterization, and application of organic and inorganic particulate-filled composites.

Several critical issues and suggestions for future work are comprehensively discussed in this book with the hope that it will provide a deep insight into the state of the art of fillers. I would like to thank the publisher and Ms. Maja Bozicevic for invaluable help in the organization of the editing process. Next, a special thanks go to those who invested their time and effort in the compilation of the material that became this book. Many authors who contributed their expertise and perspectives are clearly the backbone of this work and they deserve the lion's share of the commendations.

> **Dr. Amar Patnaik** Malaviya National Institute of Technology, Jaipur, India

**1**

**Chapter 1**

Films

**Abstract**

and oxidation.

**1. Introduction**

physicochemical properties

*and Mehmet Hakki Alma*

The Effects of Novel Additives

Used in PVA/Starch Biohybrid

The main aim of this chapter is to indicate the importance of additives and modifications used for PVA/starch biohybrid films. The additives and modifications used to improve the mechanical, thermal, and morphological properties of films are plasticizers, cross-linkers, fillers, physical and chemical treatment, and natural materials as well as thermoplastic starch. Plasticizers are preferred for higher molecular dynamism because of flexibility of functional groups in PVA and starch. Their flexibility is considerably affected by carboxyl and hydroxyl groups of plasticizers. The use of cofunctional groups increases the plasticity, flexibility, and physicochemical and mechanical properties of films. Moreover, cross-linking modifications are also effective to enhance the properties of biofilms. These

modifications improve the tensile strength, modulus of elasticity, water resistance, thermal resistance, swelling behavior, and antibacterial activity of films. Fillers are also used to enhance the properties of PVA/starch films. In this way, the properties such as gas barrier, mechanical stiffness, transparency and thermal stability of the filler-added films are improved. The chemical and physical modifications provide stronger hydrogen bonds in films due to increasing carboxyl groups. Thus, the physical, biological, and chemical properties of films are improved because of the changing molecular structure via esterification, etherification, hydrogen bonding,

**Keywords:** PVA/starch biobased films, modifications, formation methods,

Petrochemical-based plastics are being replaced by biobased materials because

of being widely eco-friendly. In the last decades, the biobased films have been investigated due to their biodegradability and for being suitable , generally obtainable, and less expensive materials in the industry. The plastics produced from petrochemical sources (e.g., polyesters and polyolefins) have been commonly used in the packaging industry due to their potential features. They are obtainable in large quantities and at low cost, displaying advantageous properties (i.e., good tensile strength, enriched barrier properties, and heat sealing) and applicability in the industry [1, 2]. However, these plastics are totally nonbiodegradable and

*Eyyup Karaogul, Ertugrul Altuntas, Tufan Salan* 
