| Abstract
| - A new carbon-13 NMR method is presented for the quantitative determination of monomersequence distributions and average sequence lengths in propylene−1-butene copolymers. Complete carbon-13 NMR chemical shift assignment was finalized: the peaks corresponding to comonomeric sequencedistributions are assigned in terms of previous assignments, and other peaks are formulated afterobservation of two reference systems: a propylene homopolymer and a propylene copolymer with 8.17mol % 1-butene. Particular attention was focused on determination of the P-centered triad sequencedistributions, and the monomer sequence distributions were quantitatively determined, based directlyon either the isolated carbon-13 NMR peaks or on the sequence distribution relationship equations. Inaddition, the effect of the propylene sequence configuration on the quantitative determination of themonomer sequence distributions of PP-centered tetrads was minimized. Molecular microstructuralinformation was extracted with the highest possible accuracy. This method is reliable for analysis of themonomer sequence distributions in propylene−1-butene random copolymer.
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