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Reactivity ratios and copolymer properties of 2‐(diisopropylamino)ethyl methacrylate with methyl methacrylate and styrene
Author(s) -
Faraguna Fabio,
Vidović Elvira,
Jukić Ante
Publication year - 2015
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4949
Subject(s) - copolymer , reactivity (psychology) , methyl methacrylate , polymer chemistry , polystyrene , styrene , monomer , methacrylate , materials science , polymerization , thermal stability , chemistry , organic chemistry , polymer , medicine , alternative medicine , pathology , composite material
Free radical copolymerization kinetics of 2‐(diisopropylamino)ethyl methacrylate ( DPA ) with styrene ( ST ) or methyl methacrylate ( MMA ) was investigated and the corresponding copolymers obtained were characterized. Polymerization was performed using tert ‐butylperoxy‐2‐ethylhexanoate (0.01 mol dm −3 ) as initiator, isothermally (70 °C) to low conversions (<10 wt%) in a wide range of copolymer compositions (10 mol% steps). The reactivity ratios of the monomers were calculated using linear Kelen–Tüdős ( KT ) and nonlinear Tidwell–Mortimer ( TM ) methods. The reactivity ratios for MMA / DPA were found to be r 1 = 0.99 and r 2 = 1.00 ( KT ), r 1 = 0.99 and r 2 = 1.03 ( TM ); for the ST / DPA system r 1 = 2.74, r 2 = 0.54 ( KT ) and r 1 = 2.48, r 2 = 0.49 ( TM ). It can be concluded that copolymerization of MMA with DPA is ideal while copolymerization of ST with DPA has a small but noticeable tendency for block copolymer building. The probabilities for formations of dyad and triad monomer sequences dependent on monomer compositions were calculated from the obtained reactivity ratios. The molar mass distribution, thermal stability and glass transition temperatures of synthesized copolymers were determined. Hydrophobicity of copolymers depending on the composition was determined using contact angle measurements, decreasing from hydrophobic polystyrene and poly(methyl methacrylate) to hydrophilic DPA . Copolymerization reactivity ratios are crucial for the control of copolymer structural properties and conversion heterogeneity that greatly influence the applications of copolymers as rheology modifiers of lubricating oils or in drug delivery systems. © 2015 Society of Chemical Industry