Abstract
Surface functionalization of the materials to achieve functionalities like thermal responsiveness has found increasing interest. In the current study, such a functionalization with poly(N-isopropylacrylamide) (PNIPAAM) polymer has been reported by controlled grafting from the surface of aggregated particles to form macroporous monoliths. The particles were first modified with a thin polymer shell of a functional monomer 2-(2-bromopropionyloxy) ethyl acrylate, BPOEA (or copolymer with styrene), which also contained a terminal atom transfer radical polymerization (ATRP) moiety. Surfactant free emulsion polymerization was carried out to generate polystyrene seed particles as well as the shell around them. Due to the colloidal unstability of BPOEA polymer chains, stable particles were formed only in presence of excess molar amount of styrene (styrene to BPOEA mole ratio of 3:1) or seed particles. Collapse of the BPOEA polymer chains on the seed particles was also enhanced by the addition of salt in the shell forming monomer batch, which did not allow the formation of stable secondary particles. The surface morphology of the particles was affected both by the kinetic collapse of the BPOEA chains on surface of the particles and subsequent polymerization as well as efficient stirring of the contents. The emulsifier free particles could not be gelated by the addition of salt and were destabilized by shear. The resulting aggregates were stable and porous which allowed simultaneous grafting of PNIPAAM polymer from the surface as well as imparted dimensional stability to the structure during the grafting process. It was also required to optimize the extent of grafting as the excess grafting could reduce the porosity of the structure.
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Jordan R, Ulman A, Kang JF, Rafailovich MH, Sokolov J (1999) J Am Chem Soc 121:1016
Ingall MDK, Honeyman CH, Mercure JV, Bianconi PA, Kunz RR (1999) J Am Chem Soc 121:3607
Wu T, Efimenko K, Genzer J (2001) Macromolecules 34:684
Zhao B, Brittain WJ (2000) Macromolecules 33:8813
Kim J, Bruening ML, Baker GL (2000) J Am Chem Soc 122:7616
Sun T, Wang G, Feng L, Liu B, Ma Y, Jiang L et al (2004) Angew Chem Int Ed 43:357
Xiong L, Liang H, Wang R, Chen L (2011) J Polym Res 18:1017
Wang W, Tang J, Jia Z, Li X, Xiao Z (2012) J Polym Res 19:9804
Zhang F, Lei X, Su Z, Zhang H (2008) J Polym Res 15:319
You YZ, Hong CY, Pan CY, Wang PH (2004) Adv Mater 16:1953
D’Agosto F, Charreyre M-T, Pichot C, Gilbert RG (2003) J Polym Sci A 41:1188
Wang XS, Jackson RA, Armes SP (2000) Macromolecules 33:255
Nishikawa T, Ando T, Kamigaito M, Sawamoto M (1997) Macromolecules 30:2244
Coca S, Jasieczek C, Beers KL, Matyajaszewski K (1998) J Polym Sci A 36:1417
Gaynor SG, Qiu J, Matyajaszewski K (1998) Macromolecules 31:5951
Mittal V, Matsko NB, Butte A, Morbidelli M (2007) Eur Polym J 43:4868
Lahann J, Mitragotri S, Tran T, Kaido H, Sundram J, Choi IS et al (2003) Science 299:371
Yoshioka H, Mikami M, Nakai T, Mori Y (1994) Polym Adv Technol 6:418
Ringsdorf H, Sackmann E, Simon J, Winnik FM (1993) Biochim Biophys Acta 1153:335
Bae YH, Okano T, Kim SW (1990) J Polym Sci B 28:923
Heskins M, Guillet JE (1968) J Macromol Sci Chem A2:1441
Yoshida R, Uchida K, Kaneko Y, Sakai K, Kikuchi A, Sakurai Y et al (1995) Nature 374:240
Gao J, Wu C (1997) Macromolecules 30:6873
Marti N, Quattrini F, Butte A, Morbidelli M (2005) Macromol Mater Eng 290:221
Mittal V, Matsko NB, Butte A, Morbidelli M (2008) Macromol React Eng 2:215
Mittal V, Matsko NB, Butte A, Morbidelli M (2008) Macromol Mater Eng 293:491
Matyajaszewski K, Gaynor SG, Kulfan A, Podwika M (1997) Macromolecules 30:5192
Mittal V, Matsko NB, Butte A, Morbidelli M (2007) Polymer 48:2806
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The experimental work was partially carried out at ETH Zurich, Switzerland.
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Mittal, V., Matsko, N.B. Surface functionalized polymer particles and thereby generation of PNIPAAM grafted monoliths by shear aggregation and ATRP. J Polym Res 19, 25 (2012). https://doi.org/10.1007/s10965-012-0025-0
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DOI: https://doi.org/10.1007/s10965-012-0025-0