Diene polymers overview

Chapter 22 presents the different types of polymers produced from ethylene, propylene, and copolymers of these olefins with other monomers, along with some basic principles that apply to polyolefin synthesis and characterization. The basic features of the mechanism of the polymerization are presented first to provide a framework for the description of different catalysts and materials. After presenting different types of catalysts that have been used for the polymerization of these monomers, a more detailed description of several features of the mechanism is presented. Finally, an overview of ethylene oligomerization, as well as diene polymerization and oligomerization, is presented. The primary journal literature and patent literature on olefin polymerization is immense. Fortunately, many reviews of olefin polymerization have been published. The coverage of olefin polymerization and oligomerization in this chapter is selective, and the reader is directed to review articles for more comprehensive coverage of these topics. " ... 

The present contribution deals primarily with the polymer synthesis via ring-opening metathesis polymerization. Acyclic diene metathesis (ADMET) [20,32-38], the other metathetic route to polymers is omitted. This article intends to give a brief overview, for more details and further applications see, e.g.. Refs. [1,4,20-29]. 

The mechanism by which BHT, a simple phenolic, functions is shown in Figure 14.3. A hindered phenol, when used alone, will react with two radicals. It then becomes spent and it wiU no longer protect the polymer. These reactions are only simplihed overviews. More complex and undesirable side reactions can occur. For example, quinone formation by the reaction of an alkoxy radical at the para position of the phenoxy radical leads to color development because of the conjugated diene structure [18]. 

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