The electron diffraction by amorphous polymers

The configurations of the polyvinyl acetate, and the acrylate and methacrylate polymers revealed by electron photographs suggest a zigzag C-atom chain for the long main chain, which has the 1, 3 structure, with the side-chains alternately on the right and the left of the zigzag chains and on planes approximately perpendicular to the axis of the main chain. These side-chains are subject to lateral cohesive forces, which group them in clusters. In the clusters the side-chains tend to arrange themselves parallel to one another. In the lenses the clusters consist of a small number of side-chains without any apparent arrangement, whilst the multilayer pattern indicates a certain orientation of the side-chains with perhaps a larger number grouping together. The patterns indicate an ‘amorphous’ character which is attributed to the tendency of the side-chains to close-packing in clusters, producing distortion of the main chain and thus preventing adlineation. On the basis of this configuration some of the elastic properties of these polymers are discussed, and a note is made on the occurrence of high elasticity.