Molecules 2017, 22, 54
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the solids were completely dissolved, the solution was cooled to 0 ◦C and TiCl4 (2.4 mL, 22 mmol)
was slowly injected into the flask. After refluxing at 70 ◦C overnight, the mixture was cooled to room
temperature and 80 mL dilute hydrochloric acid (1 mol
·
L
−1) was added to it, which was extracted with
dichloromethane (3 80 mL). The collected organic layer was dried over anhydrous magnesium sulfate.
×
After solvent evaporated, the crude product was purified by a silica gel column chromatography using
petroleum ether (60–90 ◦C)/ethyl acetate (40:1) as eluent. White crystal; yield 58% (2.4 g). H-NMR
1
(400 MHz, CDCl3, δ): 7.16–7.09 (m, 8H), 7.07–7.01 (m, 9H), 6.91 (d, 1H), 6.58 (d, 1H), 4.78 (s, 1H).
3.3. Synthesis of 4-Acryloyl Tetraphenylethylene
Into a 250 mL two-necked round-bottom flask were added 4-Hydroxyl Tetraphenylethylene
(TPE-OH) (1.0 g, 3 mmol), trimethylamine (2 mL) and fresh dried THF (30 mL). After all the solids
were completely dissolved, acryloyl chloride (0.3 mL, 3.6 mmol) was injected into the flask dropwise
◦
over 20 min. After stirring at 0 C for 2 h, the reaction mixture was concentrated under vacuum.
The residue was dissolved in ethyl acetate and the resulting solution was washed with water and
brine, dried with Na2SO4 and concentrated. The crude product was purified by a silica gel column
◦
chromatography using petroleum ether (60–90 C)/ethyl acetate (100:1) as eluent. White crystal; yield
1
62% (0.83 g). H-NMR (400 MHz, CDCl3,
δ
):7.14–7.07 (m, 9H), 7.05–6.99 (m, 8H), 6.88 (d, 1H), 6.55
(d, 1H), 6.31–6.24 (q, 1H), 5.99 (d, 1H), 5.97 (d, 1H).
3.4. Synthesis of PMT and PVT
The polymerization reaction was carried out by radical polymerization under N2 and equipped
with a condenser and magnetic stirring. Into 500 mL three-necked round-bottom flask were added
TPE-a (0.3 g, 0.7 mmol), MMA (15 g, 150 mmol), AIBN (0.1 g, 0.6 mmol) and DMF (80 mL). The reaction
mixture was stirred on an oil bath at 70 ◦C under nitrogen for 16 h. The solution was then cooled
to room temperature, concentrated under vacuum and added dropwise to 500 mL of methanol
under stirring to precipitate the polymer and meanwhile remove the unreacted reactants and solvent.
The polymer was filtered by Buchner funnel, washed with methanol several times, and dried in
vacuum overnight at 40 ◦C to a constant weight. White solid; yield 86% (13.2 g). Mn: 16500, PDI: 1.78
(GPC); 1H-NMR (400 MHz, CDCl3, δ): 7.13–6.99 (multi-peak of TPE), molar ratio of TPE: 0.47%.
The PVT was synthesized using the same synthesis methods of PMT. White solid; yield 82%
(12.6 g). Mn: 12800, PDI: 1.68 (GPC); 1H-NMR (400 MHz, CDCl3,
molar ratio of TPE: 0.37%.
δ): 7.13–6.98 (multi-peak of TPE),
4. Conclusions
We have demonstrated a luminescence probe approach based on the AIE molecule to measure
the solubility parameters of PMMA and PVAc. The solubility parameters of PMMA and PVAc are
9.19 cal1/2cm−3/2 and 9.85 cal1/2cm−3/2, respectively. The measured parameter of PMMA ranges
from 9.00 cal1/2cm−3/2 to 10.00 cal1/2cm−3/2, while the solubility parameter of PMMA measured
by the turbidimetric titration ranges from 8.6 cal1/2cm−3/2 to 12.15 cal1/2cm−3/2. All these results
demonstrated that the values obtained from our method should be more accurate than those obtained
by the turbidimetric titration method, and the luminescence probe approach can also be applied to
other kinds of polymers.
Acknowledgments: The research was supported by the National Science Foundation of China (21304011).
Author Contributions: K.M.W., B.Z.T. and Q.Y. performed the research, analyzed the data and discussed the
results; S.J. and T.Y.H. designed and performed the research, and did the data analysis, manuscript writing and
revision. All authors read and approved the final manuscript.
Conflicts of Interest: The authors declare no conflict of interest.