Polybutadiene - Acrylonitrile - Methacrylic Acid Terpolymers

Rao and co-workers [201] applied Py-GC and C-NMR to the determination of sequence distribution of butadiene (B), acrylonitrile (A) - methacrylic acid (M) terpolymers. The sequence distribution was described in terms of six triads BB, B, ABA, ABB, BBA, MBB and AMB and was found to vary with the mode of addition of methacrylic acid monomer. 

Rao and co-workers [201 ] classified into (i) triads containing butadiene (B), (ii) triads containing butadiene (B) and acrylonitrile (A) and (iii) triads containing B, A and M units. These workers discuss under separate headings the following types of triads BBB, ABA, ABB-BBA, MBM, MBB and BBM mider olefinic carbon resonances BBB, ABA, ABB triads mider nitrile carbon resonances. 

The main conclusions that can be drawn from the C-NMR studies of the terpolymers can be summarised as follows  

Calculated from Sp carbon resonances, [BBB] = ttdt Calculated from Sp carbon resonances t-CH = terminal CH  

Reprinted with permission from M.R. Rao, TV. Sebastian, T.S. Radhakrishnan and P.V. Ravindran, Journal of Applied Polymer Science, 1991, 42, 3, 753. 1991, John Wiley and Sons [201 [  

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Orientations in elongated mbbers are sometimes regular to the extent that there is local crystallization of individual chain segments (e.g., in natural rubber). X-ray diffraction patterns of such samples are very similar to those obtained from stretched fibers. The following synthetic polymers are of technical relevance as mbbers poly(acrylic ester)s, polybutadienes, polyisoprenes, polychloroprenes, butadiene/styrene copolymers, styrene/butadiene/styrene tri-block-copolymers (also hydrogenated), butadiene/acrylonitrile copolymers (also hydrogenated), ethylene/propylene co- and terpolymers (with non-conjugated dienes (e.g., ethylidene norbomene)), ethylene/vinyl acetate copolymers, ethyl-ene/methacrylic acid copolymers (ionomers), polyisobutylene (and copolymers with isoprene), chlorinated polyethylenes, chlorosulfonated polyethylenes, polyurethanes, silicones, poly(fluoro alkylene)s, poly(alkylene sulfide)s. 

Table 7.27 Triad Intensity Ratios for polybutadiene (B) - acrylonitrile (A) -methacrylic acid (M) Terpolymers ...

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