tailieunhanh - Handbook of Polymer Synthesis Second Edition Episode 3

Tham khảo tài liệu 'handbook of polymer synthesis second edition episode 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 3 Poly vinyl ether s Poly vinyl ester s and Poly vinyl halogenide s Oskar Nuyken and Harald Braun Technische Universitat Munchen Garching Germany James Crivello Rensselaer Polytechnic Institute Troy New York I. POLY VINYL ETHER S A. Introduction 1. Definition and Historical Background Vinyl ethers comprise that class of olefinic monomers which possess a double bond situated adjacent to an ether oxygen. These monomers include those compounds which have various substituents attached to the carbon atoms of the double bond as well as the unsubstituted compounds. Due to the presence of the neighboring oxygen atom the double bond possesses a highly electronegative character a feature that dominates both the organic and polymer chemistry of these compounds. The analogous vinyl thioethers are also known 1 and their chemistry closely parallels that of their corresponding vinyl ether counterparts. Beginning with the accidental discovery by Wislicenus 2 that elemental iodine catalyzes the violent exothermic polymerization of ethyl vinyl ether the polymerization of these monomers has been the subject of many investigations over the years and continues to occupy the attention of investigators today. In particular the field of the cationic polymerization of vinyl ethers is a very lively field engaging the efforts of academic as well as industrial workers. Apart from the interesting chemistry of these compounds the chief incentive for these efforts is their versatility in a wide variety of technical applications. Among the many uses of poly vinyl ethers and their copolymers are applications such as adhesives surface coatings lubricants greases elastomers molding compounds films thickeners anticorrosion agents fiber and textile finishes and numerous others. Vinyl ether monomers and their polymerization and copolymerization have been the subjects of several excellent past reviews 3-7 and some more recent one 8-10 . These reviews have provided a rich source of background material .