The probabilities of compositional-eonfigtirational triads in t c r c~i c , and trrtruic. methyl methacrylate methacrylic acid copolymers are evaluated. After verification of the assignment ofsyndiotacticand isotactic triads in the 'H-NMR spectra oftcct,/ic, methyl methacrylate methacrylic acid copolymers in three NMR solvents. the chemical shifts of the heterotactic triads are postulated by shift increments. The postulated assignment of the heterotactic triads is supported by comparison of the experimental 'H-NMR peak intensities of trrrrc~ric~ methyl methacrylate pentadeuteromethacrylic acid copolymers and r r / e r c~t i c~ pentadetiteromethyl methacry late mcthacrylic acid copolymers in three NMR solvents with calculated triad probabilities. The compositional and configurational parameters needed for thc calculation of triad probabilities are determined. It is shown hou the peak areas obtained from the two partially deuterated. trrtrc.ric copolymers in different solvents may be combined to detcrminc the probabilities of all compositionalconfigurationnl triads in orccc~tic~ copoljmers. Possibilities for the evaluation of triad probabilities from the '.'C-NMR spectra of /erc,ric, and ottrc,ric, methyl methacrylate methacrylic acid copolymers are presented.

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The assignment of configurational pentads‐compositional triads in the 13C‐NMR spectra of atactic methyl methacrylate‐methacrylic acid (MMA‐MAA) copolymers is studied. Based on the known chemical shifts of the pentad‐triad sequences in syndiotactic and isotactic MMA‐MAA copolymers, as well as in atactic PMMA and atactic PMAA, chemical shift increments are derived which allow the postulation of the chemical shifts of the remaining pentad‐triad sequences. The postulated assignment of these sequences is verified by comparison of experimental 13C‐NMR peak intensities of three different types of atactic MMA‐MAA copolymers with calculated peak intensities. Because the experimental peak intensities are composed of more than one pentad‐triad resonance which strongly overlap, and can therefore be measured only as a sum, the three MMA‐MAA copolymers are chosen to possess widely differing compositional statistics at the same P(A). The calculated peak intensities are based on the copolymerization theory for the first type copolymer, which was obtained by radical‐initiated copolymerization. For the second type copolymer, derived by half‐esterification of poly(methacrylic anhydride) with methanol, the compositional‐configurational triad peak intensities are first determined by 1H‐NMR spectra using three different solvents. Some features of the statistics of this type of polymer analogous reaction are set forth, and the opening of the anhydride ring is found to be random. This fact allows the accurate calculation of the probabilities of the pentad‐triad sequences. For the third type copolymer, derived by hydrolysis of atactic PMMA in pyridine/water, a blocklike compositional triad distribution was found, which is—as opposed to the second type copolymer—statistically correlated with the configurational sequences. Only an approximate calculation of the probabilities of the pentad‐triad sequences was carried out. For all three types of copolymers a reasonable agreement between experimental and calculated pentad‐triad peak intensities was found.

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When converting a homopolymer, consisting of monomer units A, by a polymer analogous reaction into a copolymer, composed of monomer units A and B, the reversible reaction A B may be kinetically infIuenced by the two 5anking monomer units. The distribution of the blocks along the chain of the copolymer is shown to be random in the sense that the probability of a block of given length does not depend on the length of adjacent blocks. As opposed to the random distribution of the blocks in the chain, the frequency distribution of the block lengths conforms to block probabilities determined by a non-MARKOVian statistics of monomer units. The exact way t o use conditional probabilities for calculating the probabilities of sequences is presented. A method for deriving rate equations of polymer analogous reactions and their use for proving the random distribution of the blocks is described. Model copolymers obtained by Monte Carlo simulation of polymer analogous reactions confirm the random statistics of blocks and the non-MARKOVian statistics of monomer units. ZUSAMMENFASSUNG:Wird ein aus Monomereinheiten A bestehendes Homopolymeres durch eine polymeranaloge Reaktion in ein Copolymeres der Monomereinheiten A und B umgewandelt, so kann die reversible Reaktion A z B in ihrer Kinetik von den beiden benachbarten Monomereinheiten abhangen. Es wird gezeigt, da13 in den Copolymeren eine regellose Verteilung der Blocke entlang der Kette vorliegt in dem Sinne, da13 die Wahrscheinlichkeit eines Blockes bestimmter Lange nicht von der Lange benachbarter Blocke abhangt. Im Gegensatz zur regellosen Verteilung der Blocke in der Kette entspricht die Haufigkeitsverteilung der Blocklange einer nicht-MARKOFFschen Statistik der Monomereinheiten. Ein exaktes Schema fur die Anwendung von bedingten Wahrscheinlichkeiten zur Berechnung der Wahrscheinlichkeiten von Sequenzen wird angegeben. Eine Methode zur Ableitung der Geschwindigkeitsgleichungen fur polymeranaloge Reaktionen und deren Anwendung zum Beweis der regellosen Statistik der Blocke wird beschrieben. Durch Monte-Carlo-Simulation erhaltene Modellcopolymere bestatigen die regellose Statistik der Blocke und die nicht-MARKOFFsche Statistik der Monomereinheiten.