Structure and Its Ramifications

Similar studies have been conducted on poly(vinyl chloride) (PVC) to assign different IR signatures obtained from different stereo-configurational isomers. The sensitivity of the vC-Cl bond on the stereochemical environment has been utilized using IR spectroscopy. The characteristic vibrations of the vC-Cl bonds are inherently tied in to the configuration as well as the conformation of the 

trans G, gauche (G represents a gauche configuration where the rotation about the bond is in the opposite direction to G). 

A consequence of tacticity/stereoregularity is the production of regular helical coiling of the polymer chain. Helical coiling is a secondary structure for synthetic polymers associated with the primary structure of the tactic sequence. Using IR spectroscopy, it has been possible to assign some unique bands to 

Favorable rheological properties are an essential requirement for the commercialization of polyolefins like polyethylene. The ease of processability of the polymer melt, obtained through modifications in the microstructural features, is as important as the end use mechanical properties of these polymers. Presence of long-chain as well as short-chain branching, LCB and SCB, respectively, more or less dictates the rheological behavior of most commercial 

The crystallization kinetics of commercial polyolefins is to a large extent determined by the chain microstructure [58-60]. The kinetics and the regime [60] of the crystallization process determine not only the crystalline content, but also the structure of the interfaces of the polymer crystals (see also Chapter 7). This has a direct bearing on the mechanical properties like the modulus, toughness, and other end use properties of the polymer in fabricated items such as impact resistance and tear resistance. Such structure-property relationships are particularly important for polymers with high commercial importance in terms of the shear tonnage of polymer produced globally, like polyethylene and polyethylene-based copolymers. It is seen that in the case of LLDPE, which is 

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