Lacquer Chemistry and Applications

Rong Lu, Tetsuo Miyakoshi

• Publisher: Elsevier
• Year: 2015
• Print ISBN: 9780128035894
• eBook ISBN: 9780128036105
• Topic: Technology & Engineering
• Subtopic: Physical & Theoretical Chemistry
• Index: Technology & Engineering

Lacquer Chemistry and Applications explores the topic of lacquer, the only natural product polymerized by an enzyme that has been used for a coating material in Asian countries for thousands of years. Although the human-lacquer-culture, including cultivation of the lacquer tree, harvesting, and the use of lacquer sap, has a long history of more than thousand years, there is very little information available on the modern scientific methods to study lacquer chemistry. This book, based on the results of the authors' 30 years of research on lacquer chemistry, offers lacquer researchers a unique reference on the science and applications of this extremely important material. - Covers the chemistry and properties of lacquer, including synthesis of its various components - Provides up-to-date analytical techniques for lacquer identification and characterization - Discusses possible toxicity effects - Outlines new modification techniques for developing higher performance material - Presents the history of this versatile coating material that has evolved from its origins in Asian countries over thousands of years

Chapter 1

Introduction

Abstract

This chapter introduces the lacquer definition, species, distribution, collection, and yield. It starts by presenting good lacquer properties and long lacquer culture in Asian countries. It then describes distribution and species of lacquer tree in the world and continuously introduces different collected methods in different countries and areas. It finally discusses the yield and quality of lacquer sap according to meteorological conditions, growth environment, tree species, tree age, collection season, and collection techniques. By the end of the chapter the stimulate lacquer tree can increase the yield also was explained.

Keywords

Lacquer definition

Raw lacquer

Natural product

Self-drying

Toxicodendron vernicifluum

Toxicodendron succedanea

Gluta usitata

1.1 Lacquer Definition

Lacquer is a naturally occurring product that is polymerized by laccase enzyme. It is an Asian specialty and often called oriental lacquer. Lacquer has been used in Asian countries for thousands of years as a durable and beautiful coating material [1,2]. Cultural treasures and lacquerwares have maintained their lovely surfaces without losing their original beauty for more than 2000 years [3,4]. Lacquer is a sap tapped from a lacquer tree. Like the rubber tree, when the bark on the trunk of lacquer tree is scratched, a milky white sap is exuded. This exuded sap slowly trickles into a container, which may be made of shells, leaves, or bamboo. After the containers are collected, the sap is made into lacquer. Lacquer is called “Shengqi” in Chinese; “Urushi” in Japanese; “Sơn mài” in Vietnamese; “Thitsi” in Burmese, “Marea” in Cambodian; and “Rak” in Thai. Lacquer is considered to be a mystic paint.

Lacquer is a special natural product in Southeast Asia that was considered to be a mysterious coating material used in human life for thousands of years. In modern society, with the progress of studies on composition analysis, people have marveled at the ingenious composition of natural products and felt the charm of lacquer and lacquerwares.

Lacquer trees are a special tree species that grows in nature based on the principle of natural selection. Their leaves receive the sun’s rays and use photosynthesis to produce lacquer sap. Lacquer has become a useful material for human life, due to the ingenuity of humanity, which continuously attempts to improve its lifestyle and culture. Lacquer is not necessary for human survival, but is collected by humans for its special functions. However, this behavior does not contradict the principle of biological coexistence in nature; therefore, lacquer culture has continued for thousands of years, and will continue to be refined in the future.

Lacquer sap is generated by leaf photosynthesis in the presence of sunlight, air, water, and soil. The yield is low and tapping is labor intensive, so the efficiency of collection is very low, making lacquer a rare material with a very high price. Furthermore, due to the constant pursuit of aesthetic qualities by humans, lacquer application has become an art and craft, and that also increased its value. Many scientists have focused on its super durability that allows it to survive thousands of years. In 1878, Ishimatsu Sadama, then a student at the University of Tokyo, was the first to try to elucidate the composition of lacquer. From that time to now, nearly 135 years, international lacquer research has expanded, a large number of research papers have been published, and lacquer chemical research has made great progress.

Lacquer chemistry is the study of the properties of lacquer sap. In other words, lacquer chemistry separates, purifies, and analyzes the components of lacquer sap. Of course, based on the analyzed results of lacquer sap, understanding of the plant physiology of lacquer trees is also important. As the discovery of a new organic carbon bonds continues, study of the enzymatic polymerization of urushiol, its homologs, and its derivatives is also important. During the process of conversion of urushiol to a copolymer by enzyme oxidation, lacquer polysaccharides in the lacquer sap spread to form a network of polymerization. With the glycoprotein as an emulsifier and reactive stabilizers, enzymatic polymerization progresses smoothly and creates an insoluble lacquer film. The drying mechanism...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• Chapter 1: Introduction
• Chapter 2: History of lacquer chemistry
• Chapter 3: Main compositions of lacquer
• Chapter 4: Lacquer polysaccharide
• Chapter 5: Glycoprotein
• Chapter 6: Laccase
• Chapter 7: Lacquer aroma components
• Chapter 8: Lacquer allergy
• Chapter 9: Synthesis of Lacquer
• Chapter 10: Modification of lacquer
• Chapter 11: Lacquerware
• Chapter 12: Use of lacquer
• Appendix
• Index