Polydienes and Polyolefins

Polyethylene (PE) low density PE high density PE linear low density PE 

Packaging, films, tubes, tanks, containers, plastic bags, sheathing for wires 

The foDowing subsections give an overview of the most important types of technical polymers. Important additional information regarding the polymerization mechanism and about the most important polymer process technologies is in Topics 5.3.6 and 5.3.7, respectively. For more detailed information about the use and industrial production of polymers we refer to more specialized literature (e.g., Brazel 2012, Meyer 2005). 

The most important polyolefins (Table 5.3.11) are the different polyethylene qualities, polypropylene, and polybutadienes. Polyethylene is by volume the most important polymer. Therefore, its production has been chosen as a process example (Section 6.20). 

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RITCHIE, p. D. (Ed.), Vinyl and Allied Polymers, Vol. 1 —Aliphatic Polyolefins and Polydienes Fluoro-olefin Polymers, Iliffe, London (1968)... 

As with most polyolefins and polydienes the presence of copper has a strong adverse effect and most antioxidants are relatively ineffective. In these instances quite good results may be achieved by the use of 1% of a 50 50 phenol alkane-dilauryl thiodiproprionate blend instead of the 0.1-0.2% of antioxidants more commonly used in polypropylene. 

One should be aware of the fact that in the case of oxidation of polyolefins and polydienes (case (a) earlier, see, e.g., Figure 4) after an autocatalytic development... 

Table 5.1 shows the main families of polymers obtained by coordination polymerization (most of them commercial polymers), which were grouped according to their thermomechanical behavior, such as polymer and copolymers, thermoplastics, elastomers, and plastomers. Most of the polymers synthesized by coordination mechanisms correspond to different grades of polyolefins and polydienes, made with Ziegler-Natta or Phillips catalyst [31]. 

Catalysis by immobilized complexes gives opportunities for the production of new composite materials. If the macromolecular complex is used not at catalytic (or initiating) concentrations but as an ingredient, we may obtain polymer-polymer compositions (PPC) from components that are not compatible under common conditions. This approach has already been realized in the case of new type composites, i.e. polyolefin-polyvinyl PPC, chemical hybrids of polyolefins and polydienes, electroconducting PPC, etc. [119]. 

Stereoregularity and MW nonuniformity of polyolefins and polydienes Polyolefins synthesised on complex Ziegler-Natta catalysts are products without uniform stereoregularity and MW. The reason for this effect is the existence of different types of AC with different stereospecificity. On the other hand, these catalysts are kinetically nonuniform (differ in reactivity). 

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