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Simple method for preparation of thermally expandable microspheres of PMMA encapsulating NaHCO 3 via thermally induced phase separation
Author(s) -
Zhou Shuqian,
Li Zheng,
Zhou Zhengfa,
Xu Weibing,
Ma Haihong,
Ren Fengmei
Publication year - 2018
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.46179
Subject(s) - materials science , methyl methacrylate , volume (thermodynamics) , phase (matter) , chemical engineering , microsphere , composite material , nuclear chemistry , polymer chemistry , polymer , copolymer , chemistry , organic chemistry , physics , quantum mechanics , engineering
Thermally expandable microspheres (TEMs) employing poly(methyl methacrylate) (PMMA) as shell and sodium bicarbonate (NaHCO 3 ) as core were prepared by a simple method of thermally induced phase separation (TIPS). The addition of NaHCO 3 improved the foaming properties of TEMs. The effects of preparation parameters on the morphology, amount of encapsulated NaHCO 3 , and foaming properties of TEMs were studied; the parameters investigated included the quench rate, the molecular weight ( M w ) and amount of PMMA, and the amount of NaHCO 3 . The results show that when 0.5 g of PMMA 50k, 3 g of NaHCO 3 , and 50 g of ethanol were used, with quenching temperature at 0 °C, the TEMs were fully spherical and the maximum expansion volume of TEMs was about 3.8 times the original volume. The expansion volume of TEMs increased with increasing amount of encapsulated NaHCO 3 , and the foaming onset temperature and temperature of complete bursting of TEMs were related to the M w of PMMA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46179.