Stereoregular addition

Gaylord, N. G., and Mark, H. F., Linear and Stereoregular Addition Polymer. Wiley (Interscience), New York, 1959. 

Apparently very little has been done with simple barium, strontium or calcium alkyl catalysts. One can predict that they should be similar to sodium and potassium catalysts which require special conditions and selected monomers to obtain sufficient cationic attack on the monomer for stereoregular addition. Furukawa (251, 252) has obtained low crystallinity isotactic polymers from styrene and acrylic esters by using complexes of these alkyl metals with ZnR2. However, stereospecificity was attributed to multi-centered coordination involving the two metallic centers (250). 

Earlier investigations in our laboratory 56) have shown that several chain reaction polymerizations at temperatures below the melting or dissolution temperature of the final polymer lead to a thermodynamically more stable state than crystallization of the identical polymer from the polymer melt. Bawn and Ledwith mentioned in a review on stereoregular addition polymerization 57) that crystallization of the growing polymer chain might influence the polymerization step such that a more stereoregular polymer results. Ham 58—60) has finally pointed out a possible influence of the crystallization on the tacticity of the preceeding poljonerization which should only be possible when both processes are practically simultaneous. 

N. C. Gaylord, H. F. Mark, Linear and Stereoregular Addition Polymers Polymerization with Controlled Propagation, Interscience, New York, 19591... 

A. Gandini and H. Cheradame, Cationic Polymtaization in Encyclopedia of Polymer Science and Engineering, Vol. 2, H.F. Mark, N.M. Bikales, C.G. OverbergCT, and G. Menges, eds., Wiley Interscience, New-York, 1985 N.G. Gaylord and H.F. Mark, Linear and Stereoregular Addition Polymers , Interscience, N.Y., 1959... 

G.N. Gaylord, and H.E Mark, Linear and Stereoregular Addition Polymers, Interscience Publishers, John Wiley and Sons, New York, 1959. 

Gaylord,N.G., Mark,H.F. Linear and stereoregular addition polymers. New York Interscience 1959. 

The mechanisms of homogeneous ionic stereoregular addition polymerization are not properly understood and still a matter of some debate. The... 

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