Figures (11)  Tables (8)

    • Figure 1. 

      Schematic diagram of the reaction calorimeter.

    • Figure 2. 

      Quantitative characterization of purity and thermal risk parameters for 2-ANDSA diazotization (a) Temperature, (b) feed rate, (c) HCl/2-ANDSA, (d) NaNO2/2-ANDSA, (e) stirring rate.

    • Figure 3. 

      Curves showing the changes in Tr, Tj, Qr, and the amount of 30% NaNO2 solution added under the Tr and Tj modes during the 2-ANDSA diazotization reaction. (c), (d) Trend graphs of Tcf, X, Xac, and the amount of 30% NaNO2 solution added under the Tr and Tj modes during the 2-ANDSA diazotization reaction.

    • Figure 4. 

      Quantitative representation of purity and thermal risk parameters in the 2-ANDSA diazotization reaction under abnormal conditions. (a) High temperature, (b) high feeding rate, (c) low solvent (H2O)/2-ANDSA ratio.

    • Figure 5. 

      Thermal behavior and hazard assessment of 2-ANDSA diazonium salt. (a) DSC thermograms of 2-ANDSA, NaNO2, NH2SO3H, and 2-ANDSA diazonium salt. (b) Adiabatic temperature and pressure profiles of 2-ANDSA diazonium salt in ARC.

    • Figure 6. 

      (a) Arrhenius plots (lnk vs 1/T) for various reaction orders. (b) TMRad vs temperature curves under adiabatic conditions.

    • Figure 7. 

      Characterization of product after centrifugation. (a) HPLC chromatogram, (b) mass spectrum.

    • Figure 1. 

      Proposed reaction mechanism for the diazotization of 2-ANDSA.

    • Figure 8. 

      Energy profile for reaction steps 4–5.

    • Figure 9. 

      ESP surface potential distribution of 2-ANDSA molecule.

    • Figure 10. 

      (a) Transition states (TS1 and TS2) in diazotization. (b) Linear relationship of ink vs 1/T for each elementary reaction.

    • Exp no. T (°C) Feed rate (mL/min) HCl/2-ANDSA NaNO2/
      2-ANDSA      		 SR (rpm) Mode
      1 0 0.1 2 1 300 Tr
      2 10 0.1 2 1 300 Tr
      3 20 0.1 2 1 300 Tr
      4 30 0.1 2 1 300 Tr
      5 10 0.15 2 1 300 Tr
      6 10 0.2 2 1 300 Tr
      7 10 0.25 2 1 300 Tr
      8 10 0.15 2.2 1 300 Tr
      9 10 0.15 2.4 1 300 Tr
      10 10 0.15 2.6 1 300 Tr
      11 10 0.15 2.4 1.1 300 Tr
      12 10 0.15 2.4 1.2 300 Tr
      13 10 0.15 2.4 1.3 300 Tr
      14 10 0.15 2.4 1 200 Tr
      15 10 0.15 2.4 1 400 Tr
      16 10 0.15 2.4 1 500 Tr
      17 10 0.15 2.4 1 400 Tj

      Table 1. 

      Single-factor optimization of 2-ANDSA diazotization.

    • Exp no. Purity (%) Qrmax (W) MTSR (°C) ∆Hr (kJ/mol)
      1 95.2 2.3 1.1 115.6
      2 95.6 2.5 11.5 125.2
      3 93.5 3.0 31.0 125.6
      4 91.9 3.0 34.4 129.6
      5 95.6 3.0 12.2 126.1
      6 94.0 5.1 15.2 123.8
      7 88.0 5.8 16.0 103.8
      8 95.7 3.1 11.5 127.5
      9 96.7 2.9 11.0 127.4
      10 96.8 3.3 11.4 121.5
      11 92.3 5.2 11.2 114.5
      12 91.2 5.8 11.5 115.3
      13 91.2 6.5 10.8 120.0
      14 95.0 3.2 11.7 126.6
      15 97.0 5.2 14.2 125.1
      16 97.7 6.0 13.8 122.2
      17 97.1 3.1 15.1 122.2

      Table 2. 

      Purity and key thermal risk parameters.

    • Exp no. T (°C) Feed rate (mL/min) Solvent (H2O)/2-ANDSA
      1 10 0.3 4
      2 40 0.3 4
      3 50 0.3 4
      4 60 0.3 4
      5 10 0.6 4
      6 10 1.2 4
      7 10 Single addition (—) 4
      8 10 0.3 2.5
      9 10 0.3 3.0
      10 10 0.3 3.5

      Table 3. 

      Single-factor conditions for abnormal diazotization of 2-ANDSA.

    • Exp no. Purity (%) Qrmax (W) MTSR ( °C) ΔHr (kJ/mol)
      1 88.1 3.5 15.4 86.1
      2 88.0 3.3 44.8 109.0
      3 8.0 3.8 52.2 118.0
      4 0 5.1 64.9 175.0
      5 84.9 5.2 24.4 94.6
      6 81.5 11.8 25.8 113.8
      7 98.9 108.4 17.4 118.9
      8 32.8 4.6 27.9 141.0
      9 64.3 6.6 13.9 99.6
      10 89.6 3.7 12.4 89.2

      Table 4. 

      Key thermal risk parameters.

    • Chemical Mass (mg) β (°C/min) Range ( °C)
      2-ANDSA 5.90 5 20−350
      NaNO2 6.00 5 20−350
      H3NO3S 5.93 5 20−350
      2-ANDSA Diazonium Salt 6.10 5 20−350

      Table 5. 

      DSC experimental conditions.

    • Reaction step ΔH (kJ/mol) ΔG (kJ/mol)
      (1) $ {\mathit{N}\mathit{a}\mathit{N}\mathit{O}}_{2}+\mathit{H}\mathit{C}\mathit{l}\to \mathit{N}\mathit{a}\mathit{C}\mathit{l}+{\mathit{H}\mathit{N}\mathit{O}}_{2} $ −35.74 −0.01
      (2) $ {\mathit{H}\mathit{N}\mathit{O}}_{2}+\mathit{H}\mathit{C}\mathit{l}\to \mathit{N}\mathit{O}\mathit{C}\mathit{l}+{\mathit{H}}_{2}\mathit{O} $ −27.23 −32.55
      (3) $ \mathit{N}\mathit{O}\mathit{C}\mathit{l}+{\mathit{C}}_{10}{\mathit{H}}_{9}\mathit{N}{\mathit{O}}_{6}{\mathit{S}}_{2}\to {\mathit{C}}_{10}{\mathit{H}}_{9}{\mathit{O}}_{7}{\mathit{S}}_{2}{\mathit{N}}_{2}^{+}+{\mathit{C}\mathit{l}}^{-} $ 147.79 154.82
      (4) $ {\mathit{C}}_{10}{\mathit{H}}_{9}{\mathit{O}}_{7}{\mathit{S}}_{2}{\mathit{N}}_{2}^{+}\to {\mathit{C}}_{10}{\mathit{H}}_{9}{\mathit{O}}_{7}{\mathit{S}}_{2}{\mathit{N}}_{2}^{+} $
      (structural rearrangement)      		 79.28 88.78
      (5) $ {\mathit{C}}_{10}{\mathit{H}}_{9}{\mathit{O}}_{7}{\mathit{S}}_{2}{\mathit{N}}_{2}^{+}\to {\mathit{C}}_{10}{\mathit{H}}_{7}{{\mathit{O}}_{6}\mathit{S}}_{2}{\mathit{N}}_{2}^{+}+{\mathit{H}}_{2}\mathit{O} $ −108.41 −152.66
      (6) $ {\mathit{C}}_{10}{\mathit{H}}_{7}{\mathit{O}}_{6}{\mathit{S}}_{2}{\mathit{N}}_{2}^{+}+{\mathit{C}\mathit{l}}^{-}\to {\mathit{C}}_{10}{\mathit{H}}_{7}{\mathit{C}\mathit{l}\mathit{N}}_{2}{\mathit{O}}_{6}{\mathit{S}}_{2} $ −168.99 −137.27

      Table 6. 

      Enthalpy and Gibbs free energy changes for each reaction step.

    • ΔTad (K) Severity TMRad (h) Possibility Class Thermal hazard
      assessment
      25.22 1 > 24 Seldom 1 acceptable risk

      Table 7. 

      Risk matrix for 2-ANDSA diazotization.

    • Tp (°C) MTSR MTT (°C) TD24 (°C) Class
      10 14.18 100 46.93 2

      Table 8. 

      Stoessel diagram for 2-ANDSA diazotization.