Preface

Aromatic polyimides, an important class of heteroaromatic polymers, have many desirable characteristics, including excellent thermal stability in the range of -250°C to 550°C, high mechanical strength and toughness, high electric insulating properties, low thermal dimensional expansion, low dielectric constants and dissipation factors at a wide range of frequencies, as well as high radiation and wear resistance, etc. Additionally, aromatic polyimides can be processed for many different materials, such as films, fibers, carbon fiber composites, engineering plastics, foams, porous membranes, coatings, and varnishes, etc. Based on their excellent combined properties and versatile processability, aromatic polyimide materials have found extensive applications in most high-tech fields such as electric insulating, microelectronics and optoelectronics, aerospace and aviation industries.

Although the first report on the synthesis of aromatic polyimide was published in 1908, the first commercial polyimide was introduced by Dupont in the late 1960s when a successful synthetic route to high-molecular-weight polyimides was developed. However, even today the most common methods for synthesis of polyimides are still not completely understood. This is because the polymerization reaction of aromatic dianhydrides with diamines is dramatically affected by various reaction conditions, such as solvent, moisture, impurity, temperature, etc. Even the addition mode of monomers can affect the molecular weights of the formed polyimides.

There are already several books on polyimides available to readers. They are Polyimides by D. Wilson, H.D. Stezenberger, and P.M. Hergenrother in 1990, Polyimides: Fundamentals and Applications by Malay K. Ghosh and K.L. Mittal in 1996, Polyimides: Chemistry, Relationship Between Structure and Properties and Materials (in Chinese) by Meng-Xian Ding in 2006, Polyimides: Monomer Synthesis, Polymerization and Materials Preparation (in Chinese) by Meng-Xian Ding in 2011. However, all of these books describe the basic chemistry, synthesis, characterization, and fundamentals for applications of aromatic polyimides, and there is no book focusing on a systematic description of advanced polyimide materials for high-tech applications. The authors thought that this might be due to the highly proprietary nature of advanced polyimide materials. In addition, there are no books dedicated to materials processing and testing. In recent years, with the rapid development of many high-tech industries all over the world, there is an urgent need for both academic and engineering knowledge for advanced polyimide materials. The authors feel obligated to explore these subjects and contribute to this community by sharing their recent findings so as to promote the healthy development of high technologies.

It is now appropriate to present the state-of-the-art knowledge and research in this very active field. We hope this book is able to provide useful knowledge for our colleagues and to facilitate research and development in the field of advanced polymer materials. To facilitate the exchange of original research results and reviews on the design, synthesis, characterization, and applications of polyimide materials, we have written this book entitled Advanced Polyimide Materials: Synthesis, Characterization, and Applications to address many important aspects of the polyimide materials fields. This book aims to embrace important interdisciplinary topics in fundamental and applied research of advanced polyimide materials. Thus, important and interesting topics of research frontiers for a wide range of scientific and engineering areas are presented. We believe that this is a good reference book for readers interested in the design, synthesis, and applications of polyimide materials.

I express our sincere appreciation to Prof. Qing-Hua Zhang and Prof. De-Zhen Wu, who contributed to Chapter 2, Advanced Polyimide Fibers; Prof. Qing-Hua Lu and Dr. Feng Zhang, who contributed to Chapter 5, Polyimides for Electronic Applications; Dr. Xiao-Hua Ma, who contributed to Chapter 6, Polyimide Gas Separation Membranes; Assoc. Prof. Jian-Hua Fang, who contributed to Chapter 7, Polyimide Proton Exchange Membranes; Prof. Yi Zhang and Prof. Wei Huang, who contributed to Chapter 8, Soluble and Low-k Polyimide Materials. I wish to thank Prof. Jiang Zhao, Prof. Chen-Yang Liu, and Prof. Ji-Zheng Wang at my institute for valuable advice and continuous encouragement.

I am very grateful to my colleagues, Assoc. Prof. Ai-Jun Hu, Assoc. Prof. Mian Ji, Assoc. Prof. Hai-Xia Yang, Prof. Jin-Gang Liu, Dr. Li-Li Yuan, who have contributed a large amount to this book on the research into the advanced polyimide materials at my institute. I am very grateful to my students, Zhen-He Wang, Fu-Lin Liu, Dian-Rui Zhou, and Jin-Yi Zhang who have contributed to the figures, tables, photos, and references in the book. I am also very grateful to the Senior Engineer Wei-Dong Zhao, Chao Cui, and Dr. Lin-Ying Pan at the Research Institute of Aerospace Materials and Processing in Beijing and the Senior Engineer Guang-Qiang Fang at the Institute of Aerospace System Engineering in Shanghai. Finally, it is my great pleasure to thank Mrs Gang Wu, who has contributed so generously with illustrations and helpful suggestions to improve the book.

This book is supported by China Sci-Tech projects including 973 Program (2014CB643600). I look forward to receiving any comments, criticisms, and suggestions from the readership, which would be of benefit to the book and the authors. Finally, I would like to express my gratitude to my family for their support of my work.

This edition is co-published with Elsevier Inc. In accordance with Elsevier’s edition, this book follows the typeset of Elsevier, including, but not limited to, fonts, size, subscript, superscript, normal or italic letters, as a courtesy. Meanwhile, the appendix provides the conversion of SI and CGS units for reference.

Shi-Yong Yang

Institute of Chemistry, Chinese Academy of Sciences (ICCAS), Beijing, China