Chain Length and Degree of Polymerization

Let US now examine if the chain length or degree of polymerization (jDP ) of a polymer product can be calculated from the measured rate of polymerization coupled with a knowledge of the relevant kinetic parameters. 

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Note that the terms chain length and degree of polymerization can be used interchangeably, and both are represented by x. 

FIGURE 5.1 Cluster model of amylopectin. A and B denote nomenclature of branch chains, 0=reducing end, c.l. = chain length in degree of polymerization. Reprinted from Carbohydrate Research, Vol. 147, Hizukuri (1986), Polymodal distribution of the chain lengths of amylopectin, and its significance, Pages 342-347, with permission from Elsevier. 

The aforesaid complexities make it virtually impossible to write explicit general equations for the rate of polymerization, kinetic chain length, average degree of polymerization as has been done above for a completely dissociated ionic initiator. With the exception of those simple cases discussed above, each system in anionic polymerization represents a kinetically unique problem and must be solved separately. 

Since the rate constants /c, /c and /c are temperature dependent it follows that the rate of polymerization, kinetic chain length and degree of... 

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