Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber
Abstract
:1. Introduction
2. Materials and Methods
2.1. Materials
2.2. Samples Preparation and Characterizations
2.2.1. Purification of Reagents
2.2.2. UV Photopolymerization of ACN onto ENR- 25
2.2.3. Purification of ACN-g-ENR Products
2.2.4. Mechanism of Reaction
2.3. Characterizations
2.3.1. Fourier Transform Attenuated Total Reflection (FR-ATR)
2.3.2. Nuclear Magnetic Resonance (NMR)
2.3.3. Gel Permeation Chromatography (GPC)
2.3.4. Grafting and Crosslinking Studies
2.3.5. Dynamic Mechanical Analysis (DMA)
2.3.6. Differential Scanning Calorimetry (DSC)
2.3.7. Thermogravimetry Analysis (TGA) and Derivation of Thermogravimetric (DTG) Analyses
2.3.8. Dielectric Spectroscopy Study (DSS)
3. Results and Discussion
3.1. Chemical interaction
3.2. Molecular Weight Distribution Measurements (MWDM)
3.3. Grafting Efficiency and Crosslinking Density
3.4. Thermal Analyses
3.5. Dielectric Spectroscopy Study
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Sample ID | Mn (g mole−1) | Mw (g mole−1) | PDI (Mw/Mn) |
---|---|---|---|
Non-purified ENR- 25 | 990,872 | 2,460.391 | 2.48 |
Purified ENR- 25 | 178,792 | 1,287.538 | 7.20 |
LENR 25 (as control) | 8442 | 51,540 | 6.11 |
* PAN (Typical) | N/A | 150,000 | N/A |
PAN (as control) | 15,697 | 77,601 | 4.94 |
ACN10-g-ENR1 | 50,408 | 171,064 | 3.39 |
ACN15-g-ENR1 | 11,286 | 114,657 | 10.16 |
ACN20-g-ENR1 | 33,547 | 252,786 | 7.54 |
Wt Solute (W1) | Solvent (in 5 mL) | Boiling Point of Solvent | Wt of Solute after Dissolving (W2) | Solubility (%) = (W1 − W2)/W1 * 100 |
---|---|---|---|---|
0.04 g | n-Hexane | 68 °C | 0.0308 g | 23% |
0.04 g | Xylene | 138.4 °C | 0.0089 g | 78% * |
0.04 g | Toluene | 110.6 °C | 0.0307 g | 23% |
0.04 g | Tetrahydrofuran | 66 °C | 0.0171 g | 57% |
0.04 g | Chloroform | 61.2 °C | 0.0230 g | 43% |
0.04 g | 2-butanone | 79.64 °C | 0.0124 g | 69% |
0.04 g | Acetone | 56 °C | 0.0292 g | 27% |
0.04 g | DMF | 153 °C | 0.0237 g | 41% |
0.04 g | Dimethyl sulfoxide | 189 °C | 0.0121 g | 70% ** |
0.04 g | Acetonitrile | 82 °C | 0.0302 g | 25% |
Sample ID | Storage Modulus, E (MPa) | tan δ, Tg | ||
---|---|---|---|---|
At −60 °C | At 25 °C | Tan δmax | Tg °C | |
NR [5] * | 67000 | 1.6 | 2.48 | −49 |
ENR- 25 [5] * | 62000 | 2.1 | 2.62 | −24 |
ENR- 50 [5] * | 3800 | 1.9 | 2.70 | −5.7 |
NBR [46] ** | ~100 | ~ 1 | ~ 1.3 | −12 |
ACN10-g-ENR1 | 22,286 | 713 | 0.37 | −12 |
ACN15-g-ENR1 | 19,779 | 55 | 1.05 | −15.73 |
ACN20-g-ENR1 | 132,353 | 56,222 | 0.34 | 13 |
Sample ID | Tg | (50–100 °C) | (100–300 °C) | Td (300–598 °C) | |||||
---|---|---|---|---|---|---|---|---|---|
Tg1 | Tg2 | wt.% | Tmax. | wt.% | Tmax. | Td | wt.% | Tmax. | |
PAN | 97 | Nd | 9.71 | Nd | 11.34 | 237 | 326 | 20.26 | 431 |
ENR- 25 | -44 | Nd | 11.70 | 64.24 | 21.82 | Nd | 338 | 40.22 | 397 |
ACN10-g-ENR1 | -34.96 | 102.92 | 12.68 | 65.39 | 22.23 | 202 | 346 | 41.23 | 400 |
ACN15-g-ENR1 | -39.25 | 102.59 | 9.81 | 66.65 | 16.63 | 194 | 407 | 32.79 | 414 |
ACN20-g-ENR1 | -34.39 | 110.73 | 12.09 | 67.79 | 14.1 | 98 | 365 | 37.28 | 406 |
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Whba, R.; Su’ait, M.S.; Tian Khoon, L.; Ibrahim, S.; Mohamed, N.S.; Ahmad, A. Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber. Polymers 2021, 13, 660. https://doi.org/10.3390/polym13040660
Whba R, Su’ait MS, Tian Khoon L, Ibrahim S, Mohamed NS, Ahmad A. Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber. Polymers. 2021; 13(4):660. https://doi.org/10.3390/polym13040660
Chicago/Turabian StyleWhba, Rawdah, Mohd Sukor Su’ait, Lee Tian Khoon, Salmiah Ibrahim, Nor Sabirin Mohamed, and Azizan Ahmad. 2021. "Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber" Polymers 13, no. 4: 660. https://doi.org/10.3390/polym13040660
APA StyleWhba, R., Su’ait, M. S., Tian Khoon, L., Ibrahim, S., Mohamed, N. S., & Ahmad, A. (2021). Free-Radical Photopolymerization of Acrylonitrile Grafted onto Epoxidized Natural Rubber. Polymers, 13(4), 660. https://doi.org/10.3390/polym13040660