Kinetics polymer modification reaction

A large amount of theoretical work has been done on the problem of treating the kinetics of polymer modification reactions (9,10). In addition to the kinetics, the distributions of monomer units among the products of such reactions and the compositional heterogeneity of the products are of interest. The problem of treating irreversible polymer reactions is essentially solved,... 

The examples discussed herein show that very simple, easily written CSMP programs can be used to treat complex kinetic problems that are encountered in studies on polymerization, polycondensations and polymer modification reactions. It is obvious that CSMP is also applicable to problems involving polymer processing or the dynamic behavior of polymers in solution or bulk. Polymer scientists would be well advised to become familiar with this valuable program. It would also seem important to use CSMP in the classroom. We hope that the instructions and examples provided herein will help others to use CSMP programming effectively and with minimum difficulty. 

References 1 through 7 are comprehensive reviews, and references 8 through 21 are some more specific papers that provide perspectives of these diverse applications. Another chapter in the present volume [2] has been specifically devoted to the polymerization and polymer modification reactions in near-critical and supercritical fluids. The present chapter is focused on miscibility and the kinetics of pressure-induced phase separation that are central to many of the applications. 

It was previously mentioned was that a large number of minor copolymers of PET have been developed over the past 50 years, with the intent of modifying textile fiber properties and processability [2, 3], Of broader interest is that some of these textile modifications, such as PET copolymers with metal salts of 5-sulfoisophthalic acid (SIPA), have their own rich chemistries when the extent of polymer modification is increased beyond textile levels. An example of such a modification is that changing the counterions associated with SIPA can significantly effect the kinetics of polyester transesterification reactions (the... 

By adding only about ten additional statements to this program, a program for simulating reversible polymer modification and epimerization reactions was derived. Use of CSMP to generate plotted output and to evaluate kinetic parameters are also illustrated. 

The kinetic descriptions in this chapter are developed for unimolecular scission of an initiator to yield two radicals (Scheme 3.1), the most common means of generating radicals in industrial systems. Thermal initiation of monomers is an additional mechanism capable of forming primary radicals at higher temperatures, as discussed for styrene in Section 3.2.1.3. Photoinitiators that produce radicals by ultraviolet irradiation are often used to initiate crosslinking and curing reactions these polymer modification techniques are not discussed in this chapter. 

The Flory principle is one of two assumptions underlying an ideal kinetic model of any process of the synthesis or chemical modification of polymers. The second assumption is associated with ignoring any reactions between reactive centers belonging to one and the same molecule. Clearly, in the absence of such intramolecular reactions, molecular graphs of all the components of a reaction system will contain no cycles. The last affirmation concerns sol molecules only. As for the gel the cyclization reaction between reactive centers of a polymer network is quite admissible in the framework of an ideal model. 

Normally synthetic reactions for modification of these natural polymers have been conducted heterogeneously. In the absence of acceptable solvents, characterization of starting materials is difficult and reaction yields are often low due to unfavorable kinetics. Only in those cases in which the substituted products were soluble, have polymer structures been readily identifiable by instrumental analysis.. . ... 

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