Synthesis and Characterization of Periodic Polypeptides Containing Repeating —(AlaGly)_xGluGly— Sequences

We have expressed in E. coli a series of periodic polypeptides represented by sequence 1. Our objective has been an understanding of the role of chemical sequence in determining the chain folding behavior of periodic macromolecules. Molecular organization has been examined by infrared spectroscopy and ^1H and ^(13)C NMR methods and a preliminary model of the folded structure has been developed

Copolymerization of acrylonitrile and methacrylic acid. An assessment of the copolymerization mechanism

The free-radical copolymerization of acrylonitrile and methacrylic acid has been investigated in bulk at 60 °C with the aim of elucidating the best model for the polymerization. Quantitative measurements of the copolymerization compositions and diad, triad, and tetrad fractions in the comonomer sequence distribution have been determined by using elemental analysis and H, C, and C DEPT NMR. This microstructural information was found to be consistent with a terminal polymerization mechanism with r= 3.7 and r = 0.19. The penultimate model was not found to provide a statistically significant improvement over the terminal model