Star-shaped polymers containing poly(isobutyl methacrylate) (iBMA) and poly(tert-butyl methacrylate) (t-BMA) arms coupled to a 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA) core were synthesized using arm-first living anionic polymerization. Gel permeation chromatography (GPC) indicated that coupling efficiencies were high and coupled products exhibited a monomodal molecular weight distribution. The star-shaped polymer number-average molecular weights were 8-10 times higher than the precursor arm molecular weights. The ratio of coupling reagent to living chain end concentration controlled the molecular weight of the star-shaped polymer and the number of coupled arms. The molecular weight distributions of the star-shaped polymers ranged from 1.5-2.0. Due to the labile tertiary-butyl esters contained in the DHDMA cores, these star-shaped polymers were readily hydrolyzed in the presence of acid catalysts. For example, poly(iBMA) star-shaped polymers were hydrolytically stable at 25 °C and hydrolyzed readily at 65 °C in the presence of hydrochloric acid. In addition, the poly(t-BMA) containing star-shaped polymers degraded under similar conditions. The degradation process for the iBMA and t-BMA containing star-shaped polymers was confirmed using 1H NMR spectroscopy, and poly(iBMA)-block-poly(methacrylic acid) and poly(methacrylic acid) were obtained, respectively.
|ジャーナル||Proceedings of SPIE - The International Society for Optical Engineering|
|出版物ステータス||Published - 2001 12 1|
|イベント||Complex Adaptive Structures - Hutchinson Island, FL, United States|
継続期間: 2001 6 4 → 2001 6 6
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics