10.1021/ma062617s.s001
Coleen Pugh
Coleen
Pugh
Chau N. Tang
Chau N.
Tang
Marta Paz-Pazos
Marta
Paz-Pazos
Om Samtani
Om
Samtani
Adam H. Dao
Adam H.
Dao
Correlation of Free Radical Copolymerization Behavior and
Copolymer Properties with the Strength of π−π Stacking Interactions
between Aromatic Fluorocarbons and Aromatic Hydrocarbons:
Copolymerization of Styrene and Fluorinated Styrenes at the Two
Extreme Levels of Fluorination
American Chemical Society
2007
copolymers
NMR spectroscopy results
ethylene glycol contact angles
Free Radical Copolymerization Behavior
copolymerization
styrene
St
bulk
4 FS
rStrFS
PFS
2007-11-13 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Correlation_of_Free_Radical_Copolymerization_Behavior_and_Copolymer_Properties_with_the_Strength_of__Stacking_Interactions_between_Aromatic_Fluorocarbons_and_Aromatic_Hydrocarbons_Copolymerization_of_Styrene_and_Fluorinated_Styrenes_at_the_Two_Extreme_Lev/2975083
In order to determine if the alternating tendency of styrene with fluorinated styrenes in free radical
copolymerizations correlates with the strength and/or extent of π−π stacking interactions between aromatic
fluorocarbons and aromatic hydrocarbons, styrene (St) was copolymerized with 2,3,4,5,6-pentafluorostyrene (PFS)
and 4-fluorostyrene (4FS) under a variety of conditions. For the copolymerization of styrene with PFS at 25 °C,
<i>r</i><sub>St</sub><i>r</i><sub>FS</sub> = 0.048 and 0.069 in bulk and toluene, respectively, using <i>tert</i>-butylperoxy pivalate as the initiator. For the
copolymerization of styrene with PFS at 70 °C using benzoyl peroxide as the initiator, <i>r</i><sub>St</sub><i>r</i><sub>FS</sub> = 0.17 in bulk and
<i>r</i><sub>St</sub><i>r</i><sub>FS</sub> = 0.14 in toluene. For the copolymerization of styrene with 4FS, <i>r</i><sub>St</sub><i>r</i><sub>FS</sub> = 0.69 at 25 °C under redox
conditions and <i>r</i><sub>St</sub><i>r</i><sub>FS</sub> = 0.62 at 70 °C in bulk. As confirmed by <sup>1</sup>H, <sup>13</sup>C, and <sup>19</sup>F one-dimensional NMR and
<sup>1</sup>H−<sup>13</sup>C heteronuclear single quantum coherence and <sup>1</sup>H−H nuclear Overhauser effect two-dimensional NMR
spectroscopy results, St and 4FS tend to form random copolymers whereas the St-PFS copolymers tend to alternate
with the alternating tendency increasing with decreasing temperature. The glass-transition temperatures determined
by differential scanning calorimetry of the St-PFS copolymers are elevated relative to their mole-average values,
whereas those of the corresponding homopolymer blends and the St-4FS copolymers occur at mole-average values.
The water and ethylene glycol contact angles of both the St-PFS and St-4FS copolymer films occur at their
mole-average values.