Microstructures of Styrene-Acrylamide Copolymers Using 13C NMR Spectroscopy

Abstract

ABSTRACT:The microstructures of poly(styrene-co-acrylamide)s of varying composttwns, prepared by solution polymerization of styrene with N,O-bis(trimethylsilyl)acrylamide, followed by deprotection, were studied by 13 C NMR. Sequence distributions of monomers analyzed from triad proportions were found to confirm Bernoullian statistics within experimental error. The glass transition temperature (T.) of various copolymers was obtained from Barton's equation (using diad relation) and in good agreement with those determined by differential scanning calorimetry. T 8 values of alternating styrene-acrylamide copolymers were calculated.

High-Resolution Comonomer Sequencing of Blocky Brominated Syndiotactic Polystyrene Copolymers Using 13C NMR Spectroscopy and Computer Simulations

“…The N values in Table represent the average number of blocks of consecutive styrene and Br-Sty units per 100 monomer units in a chain, calculated from the triad sequence distributions according to the following equation Here, a block is at least one unit. For random copolymers, it is clear that N should increase with increasing comonomer content due to an increasing number of styrene blocks that are terminated at each end by a Br-Sty unit.…”

“…The N values in Table 3 represent the average number of blocks of consecutive styrene and Br-Sty units per 100 monomer units in a chain, calculated from the triad sequence distributions according to the following equation 55…”