Theoretical Investigation of the Hydrolytic Mechanism of α-Functionalized Alkoxysilanes as Effective Crosslinkers and the Difficulty of Deep Vulcanization in RTV Silicone Rubber
Abstract
1. Introduction
2. Computational Methods
3. Results and Discussion
3.1. Stationary Points and Pathways with α-EAMOS and H2O as an Example
3.2. The Highest Occupancy Orbit (HOMO) of Each Stationary Point of Reactions between α-, γ-EAMOS and H2O
3.3. The Reaction between α-EAMOS and HO–Si(CH3)2–OSiH3
3.4. Thermodynamic and Kinetic Parameters
- g: Wigner correction factor, g = 1 + (hν#/kbT)2/24;
- kb: Boltzmann constant (1.3806505(24) × 10−23 J·K−1);
- T: thermodynamic temperature (K);
- h: Planck constant (6.6260693(11) × 10−34 J·s);
- R: molar gas constant (8.31441 ± 0.00026 J·mol−1·K−1);
- V#: imaginary frequency of transition (cm3·mol−1);
- ΔS#: standard molar activation entropy (J·mol−1·K−1);
- ΔH#: standard molar activation enthalpy (kJ·mol−1).
- ΔG: Gibbs free energy (kJ·mol−1).
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Rate Constants k(T) (s−1) | |||
---|---|---|---|
T/K | α-C | γ-C | Si–OH |
298 | 3.23 × 10−1 | 1.09 × 10−1 | 4.80 × 10−11 |
400 | 1.48 × 103 | 3.66 × 102 | 8.81 × 10−6 |
500 | 2.10 × 105 | 4.12 × 104 | 1.04 × 10−2 |
600 | 5.79 × 106 | 9.45 × 105 | 1.16 × 100 |
700 | 6.29 × 107 | 8.76 × 106 | 3.35 × 101 |
800 | 3.79 × 108 | 4.61 × 107 | 4.19 × 102 |
900 | 1.54 × 109 | 1.66 × 108 | 2.99 × 103 |
1000 | 4.78 × 109 | 4.63 × 108 | 1.45 × 104 |
1100 | 1.21 × 1010 | 1.06 × 109 | 5.26 × 104 |
1200 | 2.63 × 1010 | 2.12 × 109 | 1.55 × 105 |
1300 | 5.09 × 1010 | 3.78 × 109 | 3.86 × 105 |
1400 | 8.98 × 1010 | 6.19 × 109 | 8.45 × 105 |
1500 | 1.47 × 1011 | 9.46 × 109 | 1.67 × 106 |
Equilibrium Constants K(T) | |||
---|---|---|---|
T/K | α-C | γ-C | Si–OH |
298 | 1.04 × 1014 | 5.79 × 1013 | 9.28 × 1011 |
400 | 1.71 × 1011 | 1.06 × 1011 | 4.56 × 108 |
500 | 4.12 × 109 | 2.73 × 109 | 5.10 × 106 |
600 | 3.48 × 108 | 2.41 × 108 | 2.49 × 105 |
700 | 6.01 × 107 | 4.26 × 107 | 2.84 × 104 |
800 | 1.61 × 107 | 1.17 × 107 | 5.50 × 103 |
900 | 5.80 × 106 | 4.26 × 106 | 1.53 × 103 |
1000 | 2.56 × 106 | 1.91 × 106 | 5.45 × 102 |
1100 | 1.32 × 106 | 9.87 × 105 | 2.34 × 102 |
1200 | 7.55 × 105 | 5.71 × 105 | 1.15 × 102 |
1300 | 4.71 × 105 | 3.59× 105 | 6.34 × 101 |
1400 | 3.15 × 105 | 2.41 × 105 | 3.79 × 101 |
1500 | 2.22 × 105 | 1.71 × 105 | 2.43 × 101 |
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Xu, H.; Gao, Y.; Liu, Z.; Bei, Y. Theoretical Investigation of the Hydrolytic Mechanism of α-Functionalized Alkoxysilanes as Effective Crosslinkers and the Difficulty of Deep Vulcanization in RTV Silicone Rubber. Materials 2018, 11, 1526. https://doi.org/10.3390/ma11091526
Xu H, Gao Y, Liu Z, Bei Y. Theoretical Investigation of the Hydrolytic Mechanism of α-Functionalized Alkoxysilanes as Effective Crosslinkers and the Difficulty of Deep Vulcanization in RTV Silicone Rubber. Materials. 2018; 11(9):1526. https://doi.org/10.3390/ma11091526
Chicago/Turabian StyleXu, Huihui, Yanhong Gao, Zihou Liu, and Yiling Bei. 2018. "Theoretical Investigation of the Hydrolytic Mechanism of α-Functionalized Alkoxysilanes as Effective Crosslinkers and the Difficulty of Deep Vulcanization in RTV Silicone Rubber" Materials 11, no. 9: 1526. https://doi.org/10.3390/ma11091526
APA StyleXu, H., Gao, Y., Liu, Z., & Bei, Y. (2018). Theoretical Investigation of the Hydrolytic Mechanism of α-Functionalized Alkoxysilanes as Effective Crosslinkers and the Difficulty of Deep Vulcanization in RTV Silicone Rubber. Materials, 11(9), 1526. https://doi.org/10.3390/ma11091526