Foreword

Since prehistoric times, humans have used animal skins for clothing, to wear and to elaborate products with different uses.

The tanning industry is characterized by exploitation of natural resources and a constant interaction with the environment. In fact, animal skins are a byproduct of the food industry. If these skins wouldn’t be processed, they become a waste to be treated and eliminated causing health and environmental problems.

Throughout history different methods of tanning that are no longer used today had been applied, that is the case of tanning using smoke. However, other methods are still used today, such as aluminum salts, a system widely employed in ancient Rome. Also, the tanning by fats was known in the pre-classical Greece and is currently used to obtain chamois. But the use of these systems represents only 1% of the current production of skin. The only traditional system (used by Egyptians, Romans and Greeks) that maintains a high importance is the vegetable tanning. However, just represents the 10% of world production, with a tendency to regain importance.

In fact, the chrome tanning method is the most widely used and represents the 90% of world production, thanks to its ease of use and good properties that gives to the skin: durability, hydrothermal resistance, touch, fullness, etc. However, the use of chromium is a controversial issue because of its toxicity and persistence in the environment that represent some of its chemical forms.

A great variety of projects have been carried out in order to minimize this impact: recycling of pickle-tanning floats, recovery and treatment of chrome floats, high exhaustion of such floats, management of solid waste containing chrome, and the use of other tanning agents to substitute chrome. Indeed, the volume Applicative Chemistry of Tanning Metallic Heterocomplexes includes essential background about the leather tanning process and the use of chromium and its environmental implications. In addition, the eBook reports the synthesis and use of tanning metallic heterocomplexes with the aim to provide the classic features of mineral leathers and at the same time to reduce environmental pollution.

This eBook is a good tool for researchers and experts of the leather industry to understand the multiple interconnection ability of functional groups of the collagen macromolecule and the action synergism of several types of tanning metals. In this eBook you will find a low-cost alternative to the chrome tanned leather by preserving their well-known characteristics.