ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Copolymers of styrene (S) and tert-butyl methacrylate (TBMA) containing 24-92 mass % of the latter monomer were investigated using a silica column with isooctane/tetrahydrofuran (THF) gradients and on a phenyl bonded-phase column by methanol (MeOH)/THF gradients using UV detection. In both cases, retention decreased with increasing TBMA content of the sample. This is in contrast to the behavior of copolymers of S and methyl methacrylate (MMA) whose retention in gradient elution on silica columns increases with MMA content due to the polarity of this unit. The inversion of elution order is a result of the bulky TBMA residues shielding the polar groups of the ester units. For copolymers of varying composition, the gradation in retention on retention on silica is quite sufficient for separating S/MMA but not for S/TBMA mixtures. The latter could be separated by composition on phenyl packings through MeOH/THF gradient elution. Block copolymers containing 80 or 92% TBMA could be baseline-separated. It was also possible to separate these samples from admixed PTBMA or PS homopolymers. Under the conditions used, the retention of a given block copolymer was somewhat higher than that of a statistical copolymer having the same composition. A block copolymer containing 80% TBMA was converted by transesterification into a S/MMA block copolymer. The elution of the latter fitted well in the sequence of S/MMA copolymers on silica column.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1989.070380914
