Compound characterization data — Skala et al., 2026

Morgan E. Skala, Adelle L. Koenig, Gabriel B. Soto, Matthew R. Golder. “Direct mechanochemical aryl amination of polystyrene for creep resistant imine elastomers.” ChemRxiv (2026). https://doi.org/10.26434/chemrxiv.15007795/v1

2-Trifluoroethyl 2-bromoisobutyrate
Identifier	Initiator-CF₃
¹H NMR (300 MHz, CDCl₃)	δ(ppm): 4.56 (q, J = 8.30 Hz, 2H), 1.97 (s, 6H)
¹⁹F NMR (470 MHz, CDCl₃)	δ(ppm): −73.66 (s)
¹H and ¹⁹F NMR spectra	Image data were not transcribed

Polystyrene with CF₃ chain-end
¹H NMR (300 MHz, CDCl₃)	δ(ppm): 7.08 (br), 7.03 (br), 6.58 (br), 6.47 (br), 4.40 (br), 3.87 (br), 3.81 (br), 2.04 (br), 1.85 (br), 1.43 (br), 1.02 (br)
¹⁹F NMR (470 MHz, CDCl₃)	δ(ppm): −73.56 (s)
GPC-MALS	Mₙ, MALS = 9.6 kDa, Đ = 1.01; dn/dc = 0.1322
Differential scanning calorimetry	Tg = 93 °C
¹H NMR, ¹⁹F NMR and differential scanning calorimetry spectra and trace	Image data were not transcribed

tert-Butyl N-(methanesulfonyloxy)carbamate
Identifier	S1
¹H NMR (500 MHz, CDCl₃)	δ(ppm): 7.83 (br s, 1H), 3.18 (s, 3H), 1.52 (s, 9H)
¹H NMR spectrum	Image data were not transcribed

[MsO–NH₃]OTf
Identifier	1
¹H NMR (500 MHz, CD₃CN)	δ(ppm): 6.30 (br, 3H), 3.29 (s, 3H)
¹⁹F NMR (470 MHz, CD₃CN)	δ(ppm): −79.8
¹H NMR spectrum	Image data were not transcribed

Aniline
¹H NMR spectrum (500 MHz, CDCl₃ with dibromomethane)	Image data were not transcribed

sec-Butylaniline, mixture of regioisomers
¹H NMR spectrum (500 MHz, CDCl₃ with dibromomethane)	Image data were not transcribed

Trifluoroacetylated sec-butylaniline
¹⁹F NMR (470 MHz, CDCl₃)	δ(ppm): −75.50, −75.57, −75.60
¹H and ¹⁹F NMR spectra	Image data were not transcribed

Mechanochemically aminated PS
¹H NMR (300 MHz, CDCl₃)	δ(ppm): 7.08 (br), 7.03 (br), 6.57 (br), 6.49 (br), 6.45 (br), 6.38 (br), 3.73 (br), 2.05 (br), 1.84 (br), 1.43 (br), 1.07 (br)
After trifluoroacetylation, ¹H NMR (300 MHz, CDCl₃)	δ(ppm): 7.09 (br), 7.05 (br), 6.57 (br), 6.50 (br), 6.45 (br), 3.81 (br), 2.05 (br), 1.90 (br), 1.84 (br), 1.43 (br), 1.26 (br)
After trifluoroacetylation, ¹⁹F NMR (470 MHz, CDCl₃)	δ(ppm): −75.46
¹⁹F NMR functionalization quantification	0.7 mol % aminated PS; the polymer’s trifluoroacetamide resonances were comparable to those of a small molecule model compound (ca. −75 ppm)
GPC-MALS-RI	Mₙ = 10.6 kDa, Đ = 1.04; dn/dc = 0.1322; a significant shift of peak retention times and a shoulder at shorter retention time were noted after BMG amination compared to the initial polymer, despite similar molar masses before and after functionalization
¹⁹F DOSY NMR	The identified N-phenyltrifluoroacetamide resonance at −75.5 ppm diffused at a similar rate to the polymer’s chain-end trifluoromethyl group shift (−73.5 ppm)
¹⁹F NMR functionalization quantification (CDCl₃ with freon-11 and fluorobenzene)	Chain-end analysis: 0.7 mol %; analysis of grafting density with fluorobenzene: 0.9 mol %; the results were in general agreement, confirming no transesterification occurred
GPC-RI, ¹H NMR, ¹⁹F NMR and ¹⁹F DOSY NMR traces and spectra	Image data were not transcribed

Trifluoroacetylated sec-butylaniline and mechanochemically aminated PS
¹⁹F NMR resonance comparison	Good resonance overlap

Mechanochemically aminated post-consumer PS substrates
Molar-mass and functionalization data	Image data were not transcribed

aPSfoam
GPC-MALS-RI	PSfoam: Mₙ = 115 kDa, Đ = 1.8, dn/dc = 0.1600; aPSfoam: Mₙ = 104 kDa, Đ = 2.0, dn/dc = 0.1075
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	1.1 mol %
GPC-RI, ¹H NMR and ¹⁹F NMR traces and spectra	Image data were not transcribed

aPSfoam prepared with aged aminating reagent 1
GPC-MALS-RI	PSfoam: Mₙ = 115 kDa, Đ = 1.8, dn/dc = 0.1600; aPSfoam: Mₙ = 126 kDa, Đ = 1.7, dn/dc = 0.1051
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	0.2 mol %
GPC-RI trace and ¹⁹F NMR spectrum	Image data were not transcribed

aPSlid prepared by mechanochemical amination
GPC-MALS-RI	PSlid: Mₙ = 113 kDa, Đ = 1.8, dn/dc = 0.1600; aPSlid: Mₙ = 96.1 kDa, Đ = 2.1, dn/dc = 0.1075
¹⁹F NMR grafting density after derivatization	0.3 mol %
GPC-RI trace and ¹⁹F NMR spectrum	Image data were not transcribed

PSpellet after mechanochemical amination
GPC-MALS-RI	PS: Mₙ = 132 kDa, Đ = 2.2, dn/dc = 0.1600; aPS: Mₙ = 65.7 kDa, Đ = 2.3, dn/dc = 0.1075
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	1.5 mol %
GPC-RI trace	Image data were not transcribed

PScup after mechanochemical amination
GPC-MALS-RI	PS: Mₙ = 117 kDa, Đ = 1.9, dn/dc = 0.1600; aPS: Mₙ = 62.2 kDa, Đ = 2.4, dn/dc = 0.1075
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	0.4 mol %
GPC-RI trace	Image data were not transcribed

PSfoam after solution-state amination
GPC-MALS-RI	PS: Mₙ = 115 kDa, Đ = 1.8, dn/dc = 0.1600; aPS: Mₙ = 119 kDa, Đ = 1.8, dn/dc = 0.1473
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	0 mol %
GPC-RI trace	Image data were not transcribed

PSlid after solution-state amination
GPC-MALS-RI	PS: Mₙ = 113 kDa, Đ = 1.8, dn/dc = 0.1600; aPS: Mₙ = 181 kDa, Đ = 1.8, dn/dc = 0.1032
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	0.5 mol %; several additional peaks in the ¹⁹F NMR spectrum after derivatization suggest side reactions occur
GPC-RI trace and ¹⁹F NMR spectrum	The GPC-RI trace caption names the initial 113 kDa comparison sample (Đ = 1.8) as PSfoam; image data were not transcribed

22-aPS-1.1
GPC-MALS-RI	PS Mₙ = 104 kDa, Đ = 2.0
Thermogravimetric analysis (10 °C min⁻¹, N₂), Td at 5 % mass loss	287 °C
Differential scanning calorimetry, second heat	Tg1 = −20 °C; Tg2 = 99 °C
Dynamic mechanical analysis temperature ramp (−70 to 200 °C, 0.03 % strain, 1 Hz, 3 °C min⁻¹)	Tg1 = −10 °C; Tg2 = 108 °C
Thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis traces and plots	Image data were not transcribed

22-aPS-0.2, 10-aPS-0.2 and 5-aPS-0.2
GPC-MALS-RI	PS Mₙ = 126 kDa, Đ = 1.7
Thermogravimetric analysis (10 °C min⁻¹, N₂), Td at 5 % mass loss	22 % wt/wt PS: 302 °C; 10 % wt/wt PS: 306 °C; 5 % wt/wt PS: 310 °C
Differential scanning calorimetry, second heat	22 % wt/wt PS: Tg1 = −17 °C, Tg2 = 94 °C; 10 % wt/wt PS: Tg1 = −16 °C, Tg2 = 95 °C; 5 % wt/wt PS: Tg1 = −20 °C, Tg2 = 95 °C
Dynamic mechanical analysis temperature ramp (−70 to 200 °C, 0.03 % strain, 1 Hz, 3 °C min⁻¹)	22 % wt/wt PS: Tg1 = −4 °C, Tg2 = 117 °C; 10 % wt/wt PS: Tg1 = −5 °C, Tg2 = 119 °C; 5 % wt/wt PS: Tg1 = −3 °C, Tg2 = 120 °C; Tg2 for the 10 and 5 % wt/wt samples was determined at a high-temperature tan(delta) peak during a temperature-sweep experiment, but little change in storage modulus was observed
Thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis traces and plots	Image data were not transcribed

22-PS, 10-PS and 5-PS
GPC-MALS-RI	PS Mₙ = 115 kDa, Đ = 1.8
Thermogravimetric analysis (10 °C min⁻¹, N₂), Td at 5 % mass loss	22 % wt/wt PS: 280 °C; 10 % wt/wt PS: 289 °C; 5 % wt/wt PS: 289 °C
Differential scanning calorimetry, second heat	22 % wt/wt PS: Tg1 = −18 °C, Tg2 = 103 °C; 10 % wt/wt PS: Tg1 = −22 °C, Tg2 = 93 °C; 5 % wt/wt PS: Tg1 = −15 °C, Tg2 = 94 °C
Dynamic mechanical analysis temperature ramp (−70 to 200 °C, 0.03 % strain, 1 Hz, 3 °C min⁻¹)	22 % wt/wt PS: Tg1 = −17 °C, Tg2 was not determined because the sample showed obvious signs of phase separation and subsequently softened at temperatures near PS Tg, resulting in extension to the limit of the DMA instrument; 10 % wt/wt PS: Tg1 = −3 °C, Tg2 = 123 °C; 5 % wt/wt PS: Tg1 = 2 °C, Tg2 = 122 °C; Tg2 for the 10 and 5 % wt/wt samples was determined at a high-temperature tan(delta) peak during a temperature-sweep experiment, but little change in storage modulus was observed
Thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis traces and plots	Image data were not transcribed

net(X)
Thermogravimetric analysis (10 °C min⁻¹, N₂), Td at 5 % mass loss	285 °C
Differential scanning calorimetry, second heat	Tg1 = −17 °C
Dynamic mechanical analysis temperature ramp (−70 to 200 °C, 0.03 % strain, 1 Hz, 3 °C min⁻¹)	Tg1 = 2 °C
Thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis traces and plots	Image data were not transcribed

aPS, 65.7 kDa
GPC-MALS-RI	Mₙ = 65.7 kDa, Đ = 2.0
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	1.5 mol %
Thermogravimetric analysis (10 °C min⁻¹, N₂), Td at 5 % mass loss	378 °C
Differential scanning calorimetry, second heat	Tg2 = 103 °C
Thermogravimetric analysis curve and differential scanning calorimetry trace	Image data were not transcribed

aPS, 126 kDa
GPC-MALS-RI	Mₙ = 126 kDa, Đ = 1.7
¹⁹F NMR grafting density (fluorobenzene internal standard after TFAA derivatization)	0.2 mol %
Thermogravimetric analysis (10 °C min⁻¹, N₂), Td at 5 % mass loss	316 °C
Differential scanning calorimetry, second heat	Tg2 = 101 °C
Thermogravimetric analysis curve and differential scanning calorimetry trace	Image data were not transcribed

PSfoam
GPC-MALS-RI	Mₙ = 115 kDa, Đ = 1.8
Thermogravimetric analysis (10 °C min⁻¹, N₂), Td at 5 % mass loss	359 °C
Differential scanning calorimetry, second heat	Tg2 = 94 °C
¹H NMR spectrum	Image data were not transcribed
Thermogravimetric analysis curve and differential scanning calorimetry trace	Image data were not transcribed

PSlid
Differential scanning calorimetry	Tg = 93 °C
¹H NMR spectrum and differential scanning calorimetry trace	Image data were not transcribed

Polyimine materials
FTIR	Disappearance of aldehyde peaks and growing in of imine peaks for all materials
Differential scanning calorimetry and dynamic mechanical analysis temperature ramps	Two clear glass transition events were observed in the 22-aPS-C materials; the 10 and 5 % wt/wt materials showed less intense high-temperature tan(δ) peaks, weaker inflections in storage modulus and weaker differential scanning calorimetry inflections around 100 °C; all polyimines displayed a rubbery plateau modulus until 200 °C, whereas 22-PS showed a sharp decline in storage modulus at high temperatures
Stacked FTIR spectra of polyimine components and net(X), A-aPS-C and A-PS materials	Image data were not transcribed