Preface

Plasticizers are a class of materials which are added not only to plastics but to cement, clay, concrete, wallboard, etc., to increase the process-ability, flexibility and durability, and of course to reduce the cost in many cases. This book deals with the plasticizers used in plastic, electrochemical, environmental, and health sectors.

This edition is comprised of 10 chapters. Without plasticizers, it is very hard to get the desirable properties in polymers. However, they, mainly phthalate plasticizers, pose serious threat to environment and health. Taking these concerns into account, the last few decades have seen tremendous efforts in finding non-toxic, low cost, and effective alternatives of the existing plasticizers. In this regard, the first chapter introduces the scientific community to an innovative and breakthrough technology in the field of PVC plasticizers, by discussing in detail about FlexidoneTM plasticizers; free from physiological concerns. Saving our nature and caring for the environment is highly desirable. Hopefully, chapter 2 will be very interesting to the readers as it provides a detailed information about a new source of Collagen based bio-plasticizers that can be obtained from discarded materials from a natural source; Jumbo Squid (*Dosidicus gigas*).

The third chapter is about pharmaceutically used plasticizers. Authors have discussed in significant detail about the types, roles, nature, selection criterion, etc., of plasticizers for pharmaceutical applications. In chapter four, the authors have presented the use of plasticized polymers in pharmaceutical/bio-fields, including, as coatings and films of pharmaceutical dosage forms, membranes for transdermal drug delivery systems, in-situ implants, matrix polymer systems, and bio-adhesives. Transdermal drug delivery method is one of the non-destructive methods of drug administration. In chapter 5, authors have enlightened us about various aspects of plasticizers and transdermal drug delivery systems including the role and effectiveness of plasticizers in these systems, compositions and types of these systems, and the current developments related to transdermal formulations.

In the last few decades, the ion-selective electrodes/electrochemical sensors have been widely studied and applied in various analytical projects. The electrodes based on plastics are one of various types of electrodes, e.g. solid state electrodes, liquid membrane electrodes, and gas membrane electrodes. Plasticizers are one of the

#### XII Preface

major components of these plastic membranes. Chapters 6 and 7 discuss roles of plasticizers for the same.

Conventional liquid electrolytes have few drawbacks including leakage of hazardous liquids or gases, formation of lithium dendrite, electrolytic degradation of electrolyte, and exhibiting short-term stability due to the evaporation of the liquid phase in the cells. To address this issue, in chapter 8, authors have discussed the preparation and characterization of high molecular weight poly(vinyl chloride)–lithium tetraborate electrolyte, a solid polymer electrolytes (SPEs), plasticized by propylene carbonate.

The effect of concentration, and type of plasticizers (phthalate and non-phthalate based), on the mechanical properties of cellulose acetate butyrate organic-inorganic hybrids synthesized via sol-gel is presented in chapter 9. The author has presented tributhyl citrate (TBC) and triethyl 2-acetylcitrate (TEA) as an alternative to phthalate based plasticizers. The last chapter is very important which deals with drawbacks of plasticizers. Authors discussed the health risk assessment of phthalate esters in wastewater effluents and receiving freshwater systems.

This book is the result of hard work and dedication of the authors who tried their best to present the latest information and shared their experience in the field. The timely support from publishing process managers are thankfully acknowledged. The very friendly behavior, support, encouragement and the lively environment provided by the departmental colleagues, more specifically the Chairman of the Chemical Engineering Department, King Saud University, is gratefully acknowledged.

> **Mohammad Luqman**  Assistant Professor Chemical Engineering Department, College of Engineering, King Saud University, Kingdom of Saudi Arabia
