Ring-opening addition condensation polymerization

The other entries in Table 13.2 show that heat removal is not a problem for most ring-opening and condensation polymerizations. Polycaprolactam (also called Nylon 6) is an addition polymer, but with rather similar bond energies for the monomer and the polymer. The reaction exotherm is small enough that large parts are made by essentially adiabatic reaction in a mold. An equilibrium between monomer and polymer does exist for polycaprolactam, but it occurs at commercially acceptable molecular weights. 

There are several aspects of these polymerizations that are not well understood. In addition, the literature reports do not include details on the yields of the polymers and on the purification methods that were used. In this paper, we report the results of our studies on both the ring opening and condensation polymerizations. Our studies of the ring opening polymerizations focus on the effects of the alkylene groups on the polymerizations of the cyclic phosphonates and on the best methods for converting the poly(alkylene phosphonate)s to poly(alkylene phosphate) s. Our studies on the condensation polymerizations are more preliminary in nature and focus on the mechanism by which the polymerizations occur. 

Method of synthesis ring-opening addition polymerization of 8-caprolactone at 170°C under nitrogen with dibutyl stanneous oxide as the catalyst also condensation of 6-hydroxycaproic acid gives PCL polymerization is frequently conducted in extruder Kim, B J White, J L, Antec, 224-8, 2000 Label, M Thielemans, Chem. Soc. Rev., 38,3484-3504, 2009. 

In the next group of chapters we shall discuss condensation or step-growth polymers and polymerizations in Chap. 5, addition or chain-growth polymers and polymerizations in Chap. 6, and copolymers and stereoregular polymers in Chap. 7. It should not be inferred from this that these are the only classes of polymers and polymerization reactions. Topics such as ring-opening polymeri-... 

In step growth polymerization, initially dimer formation takes place due to condensation, addition or ring opening etc., e.g. 

Classify the polymers as to whether they are condensation or addition polymers. Classify the polymerizations as to whether they are step, chain, or ring-opening polymerizations. 

Ring-opening polymerization is different from the addition and condensation polymerizations described so far. It does not produce byproducts (e.g., water) as polycondensation does, and there is no unsaturated double bond in the monomers to lead to additional polymerization. However, some similarities do exist. Ringopening polymerization is initiated by the opening of a cyclic structure in the monomers and followed by polyaddition. As a result, a linear polymer with a chemical composition identical to that of the monomer is obtained. 

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