Polymers, chain type spherulitic crystal, growth

While spherulitic morphologies are the most widely observed forms of crystallization of linear-chain polymers, other equiaxed forms of growth of polyhedra referred to as hedrites were also reported. These less regular forms of several types of polymers showing similar birefringence in light microscopy were discussed by Geil (1958). 

At this point it is appropriate to consider the temperature coefficient of overall crystallization and in particular that of spherulite growth. Given the observation of maxima in either type of rate study, two main factors need to be considered. One is the application of the general concepts of nucleation theory to polymers. The other involves the description of the transport of chain units across the liquid-crystal interface, the transport term. 

In this chapter the overall crystallization kinetics and spherulite growth rates of the major copolymer types will be presented and analyzed. It should be recalled from the point of view of polymer crystallization that chains containing structurally different repeating units, although chemically identical, are also treated as copolymers. These include branch points and regio defects as well as stereo and geometric isomers. As a matter of convenience, the influence of cross-links will also be included in this chapter. 

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