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ICAR ATRP Polymerization‐Induced Self‐Assembly Using a Mixture of Macroinitiator/Stabilizer with Different Molecular Weights
Author(s) -
Cao Mengya,
Zhang Yixiang,
Wang Jian,
Fan Xiaoshan,
Wang Guowei
Publication year - 2019
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201900296
Subject(s) - polymerization , materials science , polymer chemistry , monomer , atom transfer radical polymerization , methacrylate , copolymer , ethylene oxide , nanoparticle , transmission electron microscopy , hildebrand solubility parameter , chemical engineering , polymer , nanotechnology , composite material , engineering
The poly[oligo(ethylene oxide) methyl ether methacrylate]s, POEOMA 24 and POEOMA 78 with average degree of polymerization (DP) of 24 and 78, respectively, are separately achieved by initiators for continuous activator regeneration (ICAR) atom transfer radical polymerization (ATRP) of OEOMA 300 monomer. The mixtures of [POEOMA 24 ] 0 /[POEOMA 78 ] 0 = 1/1, 2/1, or 4/1 are employed as macroinitiator/stabilizer to practice the ICAR ATRP polymerization‐induced self‐assembly (PISA) of benzyl methacrylate (B n MA) at 65 °C. When the obtained dispersions are sequentially cooled to room temperature, diluted into ethanol, and observed by transmission electron microscopy (TEM) measurement, the cases of [POEOMA 24 ] 0 /[POEOMA 78 ] 0 = 1/1 or 2/1 and target DP PB n MA = 100 or 200 lead to nanoparticles with irregular sizes, while the cases of [POEOMA 24 ] 0 /[POEOMA 78 ] 0 = 4/1 and target D PPB n MA = 300 give the regular ones. When the obtained dispersions at a high temperature (65 °C) are directly diluted into room temperature ethanol and observed by TEM, nanoparticles with light contrast but clear contour can be observed. The results show that the higher content of POEOMA 78 tends to improve the solubility of diblock copolymer and thus leads to insufficient stabilization of the nanoparticles. The morphological difference from the room‐temperature and 65 °C dispersions help elucidate the intrinsic character of the PISA system.