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Production of bulk solid-state PEI nanofoams using supercritical CO2

Published online by Cambridge University Press:  07 May 2013

Brian Aher
Affiliation:
Mechanical Engineering Department, University of Washington, Mechanical Engineering Building, Stevens Way, Seattle, Washington 98195
Nathan M. Olson
Affiliation:
Mechanical Engineering Department, University of Washington, Mechanical Engineering Building, Stevens Way, Seattle, Washington 98195
Vipin Kumar*
Affiliation:
Mechanical Engineering Department, University of Washington, Mechanical Engineering Building, Stevens Way, Seattle, Washington 98195
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

In this paper, a process to introduce nanoscale cells in homogeneous polyetherimide (PEI) is presented. The nanofoams produced have a bulk porosity (void fraction) in the range of 25–64%, with the average cell sizes in the range of 40–100 nm. Uniform nucleation of cells throughout the volume of the PEI specimen was observed. Supercritical CO2 at 20 MPa was used as the blowing agent and the specimens were foamed in a hot press to ensure flatness for further processing and characterization. Sorption studies showed that at 20 MPa, PEI can absorb about 10% CO2 by weight and that a 1-mm thick specimen can reach an equilibrium concentration in approximately 100 h at 45 °C. The effects of desorption time, foaming temperature, clamping pressure, and foaming time were investigated. Several nanoscale morphologies were observed through changes in the foaming temperature, which ranged from 165 to 210 °C. In one experiment, it was found that when the clamping force is increased from 1 to 10 tons, the average cell size increased from 40 to 4000 nm or by a factor of 100. This points to the clamping force as an important process variable to control the nanostructure introduced in PEI. Optimal processing conditions for the production of defect-free nanofoams are presented.

Type
Invited Papers
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Xu, X., Park, C.B., Xu, D., and Iliev, R.P.: Effects of die geometry on cell nucleation of PS foams blown with CO2. Polym. Eng. Sci. 43, 1378 (2004).CrossRefGoogle Scholar
Siripurapu, S., DeSimone, J.M., Khan, S.A., and Spontak, R.J.: Low-temperature, surface-mediated foaming of polymer films. Adv. Mater. 16, 989 (2004).CrossRefGoogle Scholar
Shimbo, M., Higashitani, I., and Miyano, Y.: Mechanism of strength improvement of foamed plastics having fine cell. J. Cell. Plast. 43, 157 (2007).CrossRefGoogle Scholar
Sundarram, S.S. and Li, W.: On thermal conductivity of micro and nanocellular polymer foams. Polym. Eng. Sci. (2013).CrossRefGoogle Scholar
Sharudin, R.W.B. and Ohshima, M.: CO2-induced mechanical reinforcement of polyolefin-based nanocellular foams. Macromol. Mater. Eng. 296, 1046 (2011).CrossRefGoogle Scholar
Collias, D.I., Baird, D.G., and Borggreve, R.J.M.: Impact toughening of polycarbonate by microcellular foaming. Polymer 35, 3978 (1994).CrossRefGoogle Scholar
Krause, B., Koops, G-H., van der Vegt, N.F.A., Wessling, M., Wübbenhorst, M., and van Turnhout, J.: Ultralow-k dielectrics made by supercritical foaming of thin polymer films. Adv. Mater. 14, 1041 (2002).3.0.CO;2-A>CrossRefGoogle Scholar
Hedrick, J.L., Russell, T.P., Labadie, J., Lucas, M., and Swanson, S.: High temperature nanofoams derived from rigid and semi-rigid polyimides. Polymer 36, 2685 (1995).CrossRefGoogle Scholar
Park, C.B., Behravesh, A.H., and Venter, R.D.: Low density microcellular foam processing in extrusion using CO2. Polym. Eng. Sci. 38, 1812 (2004).CrossRefGoogle Scholar
Miller, D., Chatchaisucha, P., and Kumar, V.: Microcellular and nanocellular solid-state polyetherimide (PEI) foams using sub-critical carbon dioxide I. Processing and structure. Polymer 50, 5576 (2009).CrossRefGoogle Scholar
Hedrick, J.L., Hawker, C.J., DiPietro, R., Jérôme, R., and Charlier, Y.: The use of styrenic copolymers to generate polyimide nanofoams. Polymer 36, 4855 (1995).CrossRefGoogle Scholar
Hongliu, S. and Mark, J.E.: Preparation, characterization, and mechanical properties of some microcellular polysulfone foams. J. Appl. Polym. Sci. 86, 1692 (2002).Google Scholar
Krause, B., Sijbesma, H.J.P., Münüklü, P., Van der Vegt, N.F.A., and Wessling, M.: Bicontinuous nanoporous polymers by carbon dioxide foaming. Macromolecules 34, 8792 (2001).CrossRefGoogle Scholar
Krause, B., Boerrigter, M.E., Van der Vegt, N.F.A., Strathmann, H., and Wessling, M.: Novel open-cellular polysulfone morphologies produced with trace concentrations of solvents as pore opener. J. Membr. Sci. 187, 181 (2001).CrossRefGoogle Scholar
Zhang, S.S.: A review on the separators of liquid electrolyte Li-ion batteries. J. Power Sources 164, 351 (2007).CrossRefGoogle Scholar
Martini, J., Suh, N.P., and Waldman, F.A.: Microcellular closed cell foams and their method of manufacture. Patent #4473665, September 25, 1984. Massechusetts Institute of Technology: USA, 1984.Google Scholar
Martini, J., Waldman, F.A., and Suh, N.P.: The production and analysis of microcellular thermoplastic foam. SPE ANTEC Tech. Pap. 28, 674 (1982).Google Scholar
Huang, S., Wu, G., and Chen, S.: Preparation of open cellular PMMA microspheres by supercritical carbon dioxide foaming. J. Supercrit. Fluids 40.2, 323 (2007).CrossRefGoogle Scholar
Kumar, V. and Weller, J.E.: A process to produce microcellular PVC. Int. Polym. Proc. 8, 73 (1993).CrossRefGoogle Scholar
Kumar, V. and Weller, J.: Production of microcellular polycarbonate using carbon dioxide for bubble nucleation. J. Eng. Ind. 116, 413 (1994).CrossRefGoogle Scholar
Murray, R.E., Weller, J.E., and Kumar, V.: Solid-state microcellular acrylonitrile-butadiene-styrene foams. Cell. Polym. 19, 413 (2000).Google Scholar
Baldwin, D.F., Park, C.B., and Suh, N.P.: A microcellular processing study of poly (ethylene terephthalate) in the amorphous and semicrystalline states. Part I: Microcell nucleation. Polym. Eng. Sci. 36, 1437 (2004).CrossRefGoogle Scholar
Baldwin, D.F. and Suh, N.P.: Microcellular poly (ethylene terephthalate) and crystallizable poly (ethylene terephthalate): Characterization of process variables, in ANTEC 92–Shaping the Future, Vol. 1; Society of Plastics Engineers, 1992; p. 1503-1507.Google Scholar
Wang, X., Kumar, V., and Li, W.: Low density sub-critical CO2-blown solid-state PLA foams. Cell. Polym. 26, 11 (2007).CrossRefGoogle Scholar
Goel, S.K. and Beckman, E.J.: Generation of microcellular polymers using supercritical CO2. Cell. Polym. 12, 251 (1993).CrossRefGoogle Scholar
Chow, T.S.: Molecular interpretation of the glass transition temperature of polymer-diluent systems. Macromolecules 13, 362 (1980).CrossRefGoogle Scholar
Nemoto, T., Takagi, J., and Ohshima, M.: Nanoscale cellular foams from a poly (propylene) rubber blend. Macromol. Mater. Eng. 293, 991 (2008).CrossRefGoogle Scholar
Nemoto, T., Takagi, J., and Ohshima, M.: Control of bubble size and location in nano/microscale cellular poly (propylene)/rubber blend foams. Macromol. Mater. Eng. 293, 574 (2008).CrossRefGoogle Scholar
Fujimoto, Y., Ray, S.S., Okamoto, M., Ogami, A., Yamada, K., and Ueda, K.: Well-controlled biodegradable nanocomposite foams: From microcellular to nanocellular. Macromol. Rapid Commun. 24, 457 (2003).CrossRefGoogle Scholar
Krause, B., Diekmann, K., Van der Vegt, N.F.A., and Wessling, M.: Open nanoporous morphologies from polymeric blends by carbon dioxide foaming. Macromolecules 35, 1738 (2002).CrossRefGoogle Scholar
Miller, D. and Kumar, V.: Microcellular and nanocellular solid-state polyetherimide (PEI) foams using sub-critical carbon dioxide II. Tensile and impact properties. Polymer 52, 2910 (2011).CrossRefGoogle Scholar
Kazarian, S.G.: Polymer processing with supercritical fluids. Polymer Sci. 42, 78 (2000).Google Scholar
Tomasko, D.L., Li, H., Liu, D., Han, X., Wingert, M.J., Lee, L.J., and Koelling, K.W.: A review of CO2 applications in the processing of polymers. Ind. Eng. Chem. Res. 42, 6431 (2003).CrossRefGoogle Scholar
Zhou, C., Vaccaro, N., Sundarram, S.S., and Li, W.: Fabrication and characterization of polyetherimide nanofoams using supercritical CO2. J. Cell. Plast. 48, 235 (2012).CrossRefGoogle Scholar
Sorrentino, L., Aurilia, M., and Iannace, S.: Polymeric foams from high performance thermoplastics. Adv. Polym. Tech. 30, 234 (2011).CrossRefGoogle Scholar
Crank, J.: The Mathematics of Diffusion (Oxford University Press: London, England, 1956), p. 45.Google Scholar