Composites of the industrially important polymer, poly(methyl methacrylate) (PMMA), were prepared by free-radical polymerization of MMA with varying amounts (1–30 wt. %) of sodium dioctylsulfosuccinate (Aerosol OT or AOT) surfactant added to the reaction mixture. The composites with AOT incorporated show enhanced resistance to thermal degradation compared to pure PMMA homopolymer, and micro-cone combustion calorimetry measurements also show that the composites are combustion-resistant. The physical properties of the polymers, particularly at low concentrations of surfactant, are not significantly modified by the incorporation of AOT, whereas the degradation is modified considerably for even the smallest concentration of AOT (1 wt. %). Structural analyses over very different lengthscales were performed. X-ray scattering was used to determine nm-scale structure, and scanning electron microscopy was used to determine μm-scale structure. Two self-assembled species were observed: large phase-separated regions of AOT using electron microscopy and regions of hexagonally packed rods of AOT using X-ray scattering. Therefore, the combustion resistance is observed whenever AOT self-assembles. These results demonstrate a promising method of physically incorporating a small organic molecule to obtain a highly thermally stable and combustion-resistant material without significantly changing the properties of the polymer.
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Deanin, R. D. Polymer Structure, Properties and Applications, (Cahners, Boston, 1972).
Birley, A. W. & Scott, M. J. Plastic Materials: Properties and Applications, (Leonard Hill, New York, 1982).
Grassie, N. & Melville, H. W. The thermal degradation of polyvinyl compounds. II. The degradation of benzoyl peroxide catalyzed polymethyl methacrylates. Proc. R. Soc. Lond. A 199, 14–23 (1949).
Yeh, J.-M., Liou, S.-J., Lin, C.-Y., Cheng, C.-Y., Chang, Y.-W. & Lee, K.-R. Anticorrosively enhanced PMMA-clay nanocomposite materials with quaternary alkylphosphonium salt as an intercalating agent. Chem. Mater. 14, 154–161 (2002).
Meneghetti, P. & Qutubuddin, S. Synthesis, thermal properties and applications of polymer-clay nanocomposites. Thermochim. Acta 442, 74–77 (2006).
Konyushenko, E. N., Stejskal, J., Trchová, M., Hradil, J., Kovářová, J., Prokeš, J., Cieslar, M., Hwang, J.-Y., Chen, K.-H. & Sapurina, I. Multi-wall carbon nanotubes coated with polyaniline. Polymer 47, 5715–5723 (2006).
Fukushima, K., Murariu, M., Camino, G. & Dubois, P. Effect of expanded graphite/layered-silicate clay on thermal, mechanical and fire retardant properties of poly(lactic acid). Polym. Degrad. Stab. 95, 1063–1076 (2010).
Yang, M., Zhang, S. & Qin, H. in Physical Properties and Applications of Polymer Nanocomposites, 454–491 (Woodhead, Cambridge, 2010)
Kuila, T., Khanra, P., Mishra, A. K., Kim, N. H. & Lee, J. H. Functionalized-graphene/ethylene vinyl acetate co-polymer composites for improved mechanical and thermal properties. Polym. Test. 31, 282–289 (2012).
Cai, D., Jin, J., Yusoh, K., Rafiq, R. & Song, M. High performance polyurethane/functionalized graphene nanocomposites with improved mechanical and thermal properties. Compos. Sci. Technol. 72, 702–707 (2012).
Zhang, T., Xu, G., Regev, O. & Blum, F. D. Low-temperature polymerization of methyl methacrylate emulsion gels through surfactant catalysis. J. Colloid Interface Sci. 461, 128–135 (2016).
Nel, A., Xia, T., Mädler, L. & Li, N. Toxic potential of materials at the nanolevel. Science 311, 622–627 (2006).
Beddoes, C. M., Case, C. P. & Briscoe, W. H. Understanding nanoparticle cellular entry: a physicochemical perspective. Adv. Colloid Interface Sci. 218, 48–68 (2015).
Eastoe., J. Surfactant Chemistry, (Wuhan University Press, Wuhan, China, 2005).
Yan, F. & Texter, J. Capturing nanoscopic length scales and structures by polymerizatioin in microemulsions. Soft Matter 2, 109–118 (2006).
Texter, J., Ge, L., Mourey, T. H. & Bryan, T. G. Polymerizable bis(2-ethylhexyl)sulfosuccinate: application in microemulsion polymerization. Langmuir 20, 11288–11292 (2004).
Ge, L. & Texter, J. Combustion resistant nanocomposites from water/AOT/MMA reverse microemulsions. Polym. Bull. 52, 297–305 (2004).
Kohlbrecher, J. & Bressler, I. Software package SASfit for fitting small-angle scattering curveshttps://kur.web.psi.ch/sans1/SANSSoft/sasfit.html
Breßler, I., Kohlbrecher, J. & Thünemann, A. F. SASfit: a tool for small-angle scattering data analysis using a library of analytical expressions. J. Appl. Cryst. 48, 1587–1598 (2015).
Doucet, M. et al SasView Version 4.1. Zenodo http://dx.doi.org/10.5281/zenodo.438138
Lyon, R. E. & Walters, R. N. Pyrolysis combustion flow calorimetry. J. Anal. Appl. Pyrolysis 71, 27–46 (2004).
Cogen, J. M., Lin, T. S. & Lyon, R. E. Correlations between pyrolysis combustion flow calorimetry and conventional flammability tests with halogen-free flame retardant polyolefin compounds. Fire Mater. 33, 33–50 (2009).
Tyndall, J. On the blue colour of the sky, the polarization of skylight, and on the polarization of light by cloudy matter generally. Proc. R. Soc. Lond. 17, 223–233 (1868).
Tyndall, J. On the action of rays of high refrangibility upon gaseous matter. Phil. Trans. R. Soc. Lond. 160, 333–365 (1870).
Heller, W. & Vassy, E. Tyndall spectra, their significance and application. J. Chem. Phys. 14, 565–566 (1946).
Heller, W., Klevens, H. B. & Oppenheimer, H. The determination of particle sizes from Tyndall spectra. J. Chem. Phys. 14, 566–567 (1946).
Hiemenz, P. C. & Lodge, T. P. Polymer Chemistry, 2nd edn (CRC Press, Boca Raton, FL, 2007).
Blum, F. D., Young, E. N., Smith, G. & Sitton, O. C. Thermal analysis of adsorbed poly(methyl methacrylate) on silica. Langmuir 22, 4741–4744 (2006).
Beevers, R. B. & White, E. F. T. Physical properties of vinyl polymers. Part 1.—Dependence of the glass-transition temperature of polymethylmethacrylate on molecular weight. Trans. Faraday Soc. 56, 744–752 (1960).
Omastová, M., Rychlý, J., Trchová, M. & Kovářová, J. Properties and thermal decomposition of polypyrrole prepared in the presence of sodium bis(2-ethylhexyl) sulfosuccinate. Des. Monomers Polym. 7, 633–646 (2004).
Kissinger, H. E. Reaction kinetics in differential thermal analysis. Anal. Chem. 29, 1702–1706 (1957).
Ferriol, M., Gentilhomme, A., Cochez, M., Oget, N. & Mieloszynski, J. L. Thermal degradation of poly(methyl methacrylate) (PMMA): modelling of DTG and TG curves. Polym. Degrad. Stab. 79, 271–281 (2003).
Manring, L. E. Thermal degradation of saturated poly(methyl methacrylate). Macromolecules 21, 528–530 (1988).
Manring, L. E. Thermal degradation of poly(methyl methacrylate). 2. Vinyl-terminated polymer. Macromolecules 22, 2673–2677 (1989).
Manring, L. E., Sogah, D. Y. & Cohen, G. M. Thermal degradation of poly(methyl methacrylate). 3. Polymer with head-to-head linkages. Macromolecules 22, 4652–4654 (1989).
Manring, L. E. Thermal degradation of poly(methyl methacrylate). 4. Random side-group scission. Macromolecules 24, 3304–3309 (1991).
Holland, B. J. & Hay, J. N. The kinetics and mechanisms of the thermal degradation of poly(methyl methacrylate) studied by thermal analysis-Fourier transform infrared spectroscopy. Polymer 42, 4825–4835 (2001).
Tretsiakova-McNally, S. & Joseph, P. Pyrolysis combustion flow calorimetry studies on some reactively modified polymers. Polymers 7, 453–467 (2015).
Rogers, J. & Winsor, P. A. Change in the optic sign of the lamellar phase (G) in the Aerosol OT/water system with composition or temperature. J. Colloid Interface Sci. 30, 247–257 (1969).
Eastoe, J., Zou, A., Espidel, Y., Glatter, O. & Grillo, I. Photo-labile lamellar phases. Soft Matter 4, 1215–1218 (2008).
Heller, W., Bhatnagar, H. L. & Nakagaki, M. Theoretical investigations on the light scattering of spheres. XIII. The ‘wavelength exponent’ of differential turbidity spectra. J. Chem. Phys. 36, 1163–1170 (1962).
Bartoň, J., Sarov, Y. & Capek, I. Polymerization of vinyl monomers in separated Winsor II (w/o) and Winsor I (o/w) microemulsion phases. Part 1: preparation and characterization of polymerizable vinyl-monomer-containing microemulsions. Des. Monomers Polym. 9, 153–168 (2006).
García, O., Sastre, R., del Agua, D., Costela, A. & García-Moreno, I. New fluorinated polymers doped with BODIPY chromophore as highly efficient and photostable optical materials. Chem. Mater. 18, 601–602 (2006).
Goldstein, J. I. & Yakowitz, H. (eds) Practical Scanning Electron Microscopy: Electron and Ion Microprobe Analysis, (Plenum, London, 1975).
Jing, B., Chen, X., Zhao, Y., Wang, X., Cai, J. & Qiu, H. Ionic self-assembled organic nanobelts from the hexagonal phase complexes and their cyclodextrin inclusions. J. Phys. Chem. B 112, 7191–7195 (2008).
Lai, W.-C. A method for preparing self-assembled gels from opaque solutions with high concentrations of AOT. Colloids Surf. A: Physicochem. Eng. Aspects 433, 139–144 (2013).
Camerel, F., Strauch, P., Antonietti, M. & Faul, C. F. J. Copper-metallomesogen structures obtained by ionic self-assembly (ISA): Molecular electromechanical switching driven by cooperativity. Chem. Eur. J. 9, 3764–3771 (2003).
Grillo, I. in Soft Matter Characterization (eds R. Borsali and R. Pecora) 723–782 (Springer, the Netherlands, 2008)
Lovell, R. & Windle, A. H. Determination of the local conformation of PMMA from wide-angle X-ray scattering. Polymer 22, 175–184 (1981).
Hammouda, B. Probing nanoscale structures—The SANS toolbox
Skouri, M., Marignan, J. & May, R. X-ray and neutron-scattering study of the lamellar and L3 phases of the system aerosol-OT-water: effect of NaCl and decane. Colloid Polym. Sci. 269, 929–937 https://www.ncnr.nist.gov/staff/hammouda/ (1991).
Calandra, P., Longo, A., Marcianò, V. & Liveri, V. T. Physicochemical investigation of lightfast AgCl and AgBr nanoparticles synthesized by a novel solid-solid reaction. J. Phys. Chem. B 107, 6724–6729 (2003).
Rayleigh, L. The incidence of light upon a transparent sphere of dimensions comparable with the wave-length. Proc. R. Soc. Lond. A 84, 25–46 (1910).
Guinier, A. & Fournet, G. Small-Angle Scattering of X-Rays, (John Wiley & Sons, New York, 1955).
Percus, J. K. & Yevick, G. J. Analysis of classical statistical mechanics by means of collective coordinates. Phys. Rev. 110, 1–13 (1958).
Vrij, A. Mixtures of hard spheres in the Percus-Yevick approximation. Light scattering at finite angles. J. Chem. Phys. 71, 3267–3270 (1979).
Kotlarchyk, M., Huang, J. S. & Chen, S.-H. Structure of AOT reversed micelles determined by small-angle neutron scattering. J. Phys. Chem. 89, 4382–4386 (1985).
Smith, G. N., Brown, P., Rogers, S. E. & Eastoe, J. Evidence for a critical micelle concentration of surfactants in hydrocarbon solvents. Langmuir 29, 3252–3258 (2013).
Smith, G. N., Brown, P., James, C., Kemp, R., Khan, A. M., Plivelic, T. S., Rogers, S. E. & Eastoe., J. The effects of counterion exchange on charge stabilization for anionic surfactants in nonpolar solvents. J. Colloid Interface Sci. 465, 316–322 (2016).
Wang, Y.-Z., Yi, B., Wu, B., Yang, B. & Liu, Y. Thermal behaviors of flame-retardant polycarbonates containing diphenyl sulfonate and poly(sulfonyl phenylene phosphonate). J. Appl. Polym. Sci. 89, 882–889 (2003).
Levchik, S. V. & Weil, E. D. Overview of recent developments in the flame retardancy of polycarbonates. Polym. Int. 54, 981–998 (2005).
Levchik, S. V. & Weil, E. D. Flame retardants in commercial use or in advanced development in polycarbonates and polycarbonate blends. J. Fire Sci. 24, 137–151 (2006).
Babrauskas, V. & Peacock, R. D. Heat release rate: the single most important variable in fire hazard. Fire Saf. J. 18, 255–272 (1992).
GNS was funded by a CASE PhD studentship (Merck Chemicals Ltd. UK, an affiliate of Merck KGaA, Darmstadt, Germany and the UK Engineering and Physical Sciences Research Council EPSRC). The Ganesha X-ray scattering apparatus used for this research was purchased under EPSRC Grant ‘Atoms to Applications’ Grant ref. EP/K035746/1. This work benefited from the use of the SasView application, originally developed under NSF Award DMR-0520547. SasView also contains code developed with funding from the EU Horizon 2020 programme under the SINE2020 project Grant No 654000. Mr Jonathan Jones (Electron and Scanning Probe Microscopy Facility, University of Bristol) is acknowledged for SEM images and EDX analysis.
The authors declare no conflict of interest.
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Smith, G., Hallett, J., Joseph, P. et al. Structural studies of thermally stable, combustion-resistant polymer composites. Polym J 49, 711–719 (2017). https://doi.org/10.1038/pj.2017.44
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