Polystyrene supramolecular networks based on DA-AD hydrogen bonds

Figures & data

Figure 1. ¹H NMR chemical shift of amide proton at different AcAP concentrations in CDCl₃ and 300 K. From upper to lower: 0.0921, 0.0417 and 0.0088 mol L⁻¹.

Figure 2. δ_N–H fitting vs. concentration in CDCl₃ at 300 K of (A) AcAP; (B) MAAM. : experimental data and black line: fitted curve.

Figure 3. Glass transition temperature (°C) vs. MAAM mass fraction in P(MAAM-co-St) copolymers, ■ experimental point; – fits T_g respecting Fox equation; – fits T_g respecting Kwei equation.

Figure 4. Glass transition (°C) vs. MAP mass fraction in P(MAP-co-St) copolymers, ■ for experimental point; – fits T_g respecting fox equation; – fits T_g respecting Kwei equation.

Figure 5. G′ storage modulus (Pa) and G″ loss modulus (Pa) of P(MAAM-co-St) in temperature ramp tests: ramping rate at 3 °C min⁻¹, frequency = 1 rad s⁻¹, strain = 10–0.1%, -●- G′ of 6 mol% MAAM; -○- G″ of 6 mol% MAAM; -▲- 17 mol% G′ of MAAM; -- G″ of 17 mol% MAAM; -■- 27 mol% G′ of MAAM; -□- G″ of 27 mol% MAAM; -◆- 30 mol% G′ of MAAM; -◇- G″ of 20 mol% MAAM; -▼- 40 mol% G′ of MAAM; -▽- G″ of 40 mol% MAAM.

Figure 6. G′ (●) storage modulus (Pa) and G″ (○) loss modulus (Pa) of P(MAAM-co-St) in frequency sweep tests at T = 200 °C strain = 10% for 6, 17 and 27 mol% of MAAM; strain = 1% for 30 mol% of MAAM; strain = 0.1% for 40 mol% of MAAM.

Figure 7. G′ Storage modulus (Pa) and G″ loss modulus (Pa) of P(MAP-co-St) in temperature ramp tests: ramping rate = 3 °C min⁻¹, frequency = 1 rad s⁻¹, strain = 10%, ●: storage modulus G′, ○: loss modulus G″. -●- G′ of 0 mol% MAP; -○- G″ of 0 mol% MAP; -▲- 2 mol% G′ of MAP; -- G″ of 2 mol% MAP; -■- G′ of 10 mol% MAP; -□- G″ of 10 mol% MAP; -◆- G′ of 15 mol% MAP; -◇- G″ of 15 mol% MAP; -▼- G′ of 20 mol% MAP; -▽- G″ of 20 mol% MAP.

Table 1. K, δ_m, δ_d and δ of monomers derived from curve-fits from Chen Model [20].

	K (M^−1)	δm (ppm)	δd (ppm)	δ (ppm)
AcAP	16.75	7.83	11.31	3.48
MAAM	6.75	5.48	7.71	2.23

Figure 8. G′ Storage modulus (Pa) and G″ loss modulus (Pa) of P(MAP-co-St) in frequency sweep tests: T = 200 °C, strain = 10%. ●: storage modulus G′, ○: loss modulus G″.

Scheme 1. Synthesis of 2-methacrylamidopyridine (MAP) from 2-aminopyridine and methacryloyl chloride.

Scheme 2. (a) Self-homodimerization between P(MAAM-co-St) chains and (b) equilibrium self-homodimerization between P(MAP-co-St) chains.

Scheme 3. Possible homodimer structures between (a) AcAP homodimer and (b) MAAM homodimer.

Table 2. Solubility of P(MAAM-co-St) in different solvents for different MAAM/styrene compositions.

	CHCl3 (r.t.)	CHCl3 (50 °C)	THF (r.t.)	THF (50 °C)	DMSO (r.t.)	DMSO (180 °C)	Mn/Mw (g M^−1)
6% MAAM	□	□	□	□	□	□	32,703/51,864
17% MAAM	□	□	□	□	□	□	38,183/55,377
27% MAAM	■	■	■	□	□	□	39,273/76,374
30% MAAM	■	■	■	■	□	□	25,758/42,858
40% MAAM	■	■	■	■	■	□	23,410/47,090

Notes: ■ = insoluble; □ = soluble.

Table 3. Solubility of P(MAP-co-St) in different solvents for different MAAM/styrene.

	CHCl3 (r.t.)	THF (r.t.)	DMSO (r.t.)	DMSO (180 °C)	Mn/Mw (g M^−1)
0% MAP	□	□	□	□	18,210/24,090
2% MAP	□	□	□	□	18,900/25,860
5% MAP	■	■	□	□	–
10% MAP	■	■	■	□	–
15% MAP	■	■	■	□	–
20% MAP	■	■	■	□	–

Notes: ■ = insoluble; □ = soluble.

Chen JS, Rosenberger F. Accurate NMR data evaluation for monomer shift, dimer shift and dimerization constant in a self associating system. Tetrahedron Lett. 1990;31:3975–3978.

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