ISSN:
0360-6376
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Monomer reactivity ratios r1 and r2 were determined in the copolymerizations of methyl methacrylate (MMA, M1) with 1, 1-diphenylethyl (DPEMA), α,α-dimethylbenzyl (DMBMA), tert-butyl (t-BuMA), diphenylmethyl (DPMMA), phenyl (PhMA), and 1-naphthyl (NpMA) methacrylates (M2) in tetrahydrofuran (THF) by azobisisobutyronitrile (AIBN) at 60°C and butyllithium (n-BuLi) at -78°C. The reactivities of the monomers were explained in terms of the polar effect of the ester groups in both copolymerizations. All the copolymers isolated in low yields were converted to PMMA either directly or by copoly(MMA - methacrylic acid) to determine the triad tacticities of the copolymers. Coisotactic parameters σ12 and σ21 were determined by assuming the terminal model statistics. The σ21 values always accorded to the σ21 values within experimental error, and in radical copolymerizations they were between isotactic parameters σ11 and σ22 of the homopolymerizations of MMA and M2 monomers. In anionic copolymerizations, however, the σ12 = σ21 values varied, depending on the M2 monomers. In copolymerization with DPEMA the values were less than both σ11 and σ22 with DMBMA they were between σ11 and σ22, with DPMMA, nearly equal to σ11, and with PhMA and NpMA, greater than both σ11 and σ22. The application of these parameters to copolymerizations performed at high conversion was also investigated.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1979.170170424
Permalink
