Configurations and Crystallinity of Polymeric Materials

So far, we have examined the broader aspects of molecular architecture in chainlike molecules, along with the relationship between the polymerization mechan- 

Further, when a diene is polymerized, it ean react in the two following ways by the use of the appropriate catalyst  

The necessary condition for chainlike molecules to fit into a crystal lattice is that they demonstrate an exactly repeating molecular structure along the chain. For vinyl polymers, this prerequisite is met only if they have predominantly head-to-tail placement and are highly tactic. When these conditions are satisfied, polymers can, indeed, form highly crystalline domains in the solid state and in concentrated solution. There is even evidence of the formation of microcrystalline 

A qualitative notion of the nature of crystallinity in polymers can be acquired by considering the crystalli2ation process itself It is assumed that a polymer in bulk is at a temperature above its melting point, r ,. As the polymer is cooled, collections of highly tactic repeat units that are positioned favorably to move easily into a crystal lattice will do so, forming the nuclei of a multitude of crystalline domains. As the crystalline domains grow, the chain molecules must reorient themselves to fit into the lattice. 

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