Herbert Morawetz

Some applications of fluorimetry to synthetic polymer studies.

Fluorimetry, a powerful research tool in the study of biological macromolecules, has a number of valuable applications in investigations of synthetic polymers. These techniques reveal the microscopically heterogeneous distribution of species in polymer systems, which is specially pronounced in solutions of polyelectrolytes. They also allow us to study conformational mobility of flexible chains, diffusion-controlled intermolecular reactions of macromolecular reagents, glass transition phenomena, and polymer compatibility.

On the versatility of fluorescence techniques in polymer research

Examples are given for the application of fluorescence to the study of the following polymer problems: (a) the excluded volume effect as reflected in the kinetics of interpolymer reactions; (b) evidence for the microheterogeneity of polymer solutions; (c) kinetics of conformational transitions of polymer chain backbones. (d) Interpenetration of polymer chains; (e) the structure and molecular association of polymers in water solution; (f) ionomer behavior; (g) the antenna effect.

Polymerization and Other Organic Reactions in the Crystalline State

Reactions of molecular crystals which do not involve polymerization may exhibit several features reflecting the crystalline order of the reagent, e.g., (a) anisotropy of reactions of the crystals with gases, (b) topotaxy, (c) selection of one of several possible reaction paths, (d) the formation of optically active reaction products from achiral or racemic reagents by the influence of a chiral crystal environment. Solid-state polymerizations are discussed particularly with respect to topotactic effects and the control of the reaction product by the geometric arrangement of monomer molecules in the monomer crystal. The survey deals with (a) the polymerization of trioxane, (b) the polymerization of crystals of vinyl monomers and their clathrate complexes, (c) the “polydimerization” of Ephenylene diacrylic acid derivatives and of distyrylpiperazine and (d) the preparation of large single polymer crystals by the homogeneous solid-state polymerization of diacetylene derivatives.