The behaviour in supercritical CO2 of block copolymers containing styrenic, butadiene, and methacrylic or perfluroalkyl blocks is studied in view of a specific swelling and foaming by a gas dissolution process. These block copolymers are considered as neat materials or as additives in blends e.g in polystyrene (PS) or polymethylmethacrylate (PMMA) matrices.
In both cases (neat or blend) the copolymers may exhibit a structuration at a micro or nano level. The phase separated (nano) structures depend on the block type and the concentration of copolymers in the polymer matrix, so that micelles, vesicles, lamellas, or warm-like structures are generated.
Furthermore when one block is chosen as a highly CO2-philic moiety, the nanostructures are able to act as CO2 reservoirs. The result is the possibility to control microcellular foaming, or sometimes nanocellular foaming, of commodity amorphous polymers such as PMMA and PS. Besides, at room temperature, the blocks can be either glassy or rubbery in order to freeze the growth and coalescence of cells during foaming.
Different cellular polymers were elaborated by varying either the copolymer type or the foaming conditions (saturation pressure, temperature, depressurization rate). Cell sizes are accessible in a range from 0.2 to 200 μm, and densities from 0.40 to 1 g/cm3.
It is also shown that nanostructuring polymers are also efficient to produce polymer foams with oriented / structured voids.
This new approach could be used to produce nanocellular or ultra microcellular polymer foams in a simple process, using blending and extrusion.
Get full access to this article
View all access options for this article.
References
1.
Production of controlled polymeric foams by supercritical CO2, ReverchonE., and CardeaS., J. of Supercritical Fluids, 40, 144–152 (2007).
2.
Change of glass transition temperature of polymers containing gas, YoonJ. D., ChaS. W.Polymer Testing, 20(3), 287–29 (2001).
3.
Layered-silicate based polystyrene nanocomposite microcellular foam using supercritical carbon dioxide as blowing agent, ZhuBin, ZhaWeibin, YangJintao, ZhangCailiang, James LeeL., Polymer, 51, 2177–2184 (2010).
4.
Synthesis and processing of PMMA carbon nanotube nanocomposite foams, ZengChangchun, HossienyNemat, ZhangChuck, WangBen, Polymer, 51, 655–664 (2010).
5.
Controlled Foaming of Polymer Films through Restricted Surface Diffusion and the Addition of Nanosilica Particles or CO2-philic Surfactants, SiripurapuSrinivas, DeSimoneJoseph M., KhanSaad A., SpontakRichard J., Macromolecules, 38, 2271–2280 (2005).
6.
The effect of dispersed elastomer particle size on heterogeneous nucleation of TPO with N2 foaming, SeongG. Kim, SiuN. Leung, ParkChul B, SainMohini, Chemical Engineering Science, 66, 3675–3686 (2011).
7.
Control of bubble size and location in nano/micro scale cellular PP/rubber blend foams, NemotoT, TagakiJ, OhshimaM, Macrom. Mol. Eng. Sci., 293, 574–580 (2008).
8.
Effect of the Introduction of Polydimethylsiloxane on the Foaming Behavior of Block-Copolymerized Polypropylene, WangMingyi, MaJun, ChuRaymond, ParkChul B., NanqiaoZhou, Journal of Applied Polymer Science, 123, 2726–2732 (2012).
9.
Foaming behavior of isotactic polypropylene in supercritical CO2 influenced by phase morphology via chain grafting, ZhaiWentao, WangHongying, YuJian, DongJin-Yong, HeJiasong, Polymer, 49, 3146–3156 (2008).
10.
Directing the self-assembly of block copolymers, DarlingS.B., Prog. Polym. Sci., 32, 1152–1204 (2007).
11.
Controlling the size of nanostructures in thin films via blending of block copolymers and homopolymers, PengJuan, GaoXiang, WeiYuhan, WangHanfu, LiBinyao, and HanYanchun, The J. of Chem Phys., 122, 114706(1-7) (2005).
12.
Molecular Disorder and Mesoscopic Order in Polydisperse Acrylic Block Copolymers Prepared by Controlled Radical Polymerization, RuzetteA.V, Tencé-GiraultS., LeiblerL., ChauvinF., BertinD., GuerretO., GérardP., Macromolecules, 39, 5804–5814 (2006).
13.
Morphology and mechanical properties of poly(methylmethacrylate)-bpoly(alkylacrylate)-b-poly(methylmethacrylate), TongJ.D., LeclerePh., DoneuxC., BredasJ.L., LazzaroniR., JéromeR., Polymer, 42, 3503–3514 (2001).
14.
Microdeformation mechanisms in rubber toughened PMMA and PMMA-based copolymers, LalandeLaure, PlummerChristopher J.G., MansonJan-Anders E., GerardPierre, Engineering Fracture Mechanics, 73, 2413–2426 (2006).
15.
Controlled Architecture Polymers at Arkema: Synthesis, Morphology and Properties of All-Acrylic Block Copolymers, GerardP., BoupatN. P, FineT., GervatL., PascaultJ-P., Macromol. Symposium256, 55–64 (2007).
16.
Annealing and Defect Trapping in Lamellar Phases of Triblock Terpolymers, Laurent Corte, Kazuhiro Yamauchi, Francois Court, CloıtreMichel, HashimotoTakeji, LeiblerLudwik, Macromolecules, 36, 7695–7706 (2003).
17.
Investigation of a Strategy for Well Controlled Inducement of Microcellular and Nanocellular Morphologies in Polymers, JananiHamed, FamiliM.H.N., Polym Eng and Sci, 10, 1558–1570 (2010).
18.
Block Copolymers as Precursors to Porous Materials, RussellT. P., and HedrickJ. L., Encyclopedia of Materials: Science and Technology ISBN: 0-08-0431526, pp. 692–695 (2001).
19.
Block Copolymer Micelles for Nucleation of Microcellular Thermoplastic Foams, SpitaelPieter, MacoskoChristopher W., McClurgRichard B., Macromolecules, 37, 6874–6882 (2004).
20.
Thermodynamics and Kinetic Processes of Polymer Blends and Block Copolymers in the Presence of Pressurized Carbon Dioxide, WalkerTeri A., FrankowskiDavid J., SpontakRichard J., Adv. Mater., 20, 879–898 (2008).
21.
Thermally robust nanocellular thin films of high-Tg semifluorinated block copolymers foamed with supercritical carbon dioxide, ZhangRui, DutriezCedric, SugiyamaKenji, IshizoneTakashi, YokoyamaHideaki, Soft Matter, 7, 4032–4038 (2011).
22.
Nanocellular structures in block copolymers with CO2-philic blocks using CO2 as a blowing agent: Crossover from micro- to nano-cellular structures with depressurization temperature, YokoyamaH., SugiyamaK., Macromolecules, 38, 10516–10522 (2005).
Foaming behaviour and compressive properties of microcellular nanostructured polystyrene, RegleroJ.A., ViotP., DumonM., Cellular Polymers, 28(6), 363–386 (2009).
25.
Micro and nano cellular amorphous polymers (PMMA, PS) in supercritical CO2 assisted by nanostructured CO2-philic block copolymers – One step foaming process, RegleroJ.A., TallonJ.M., PedrosM., DumonM., Journal of Supercritical Fluids, 58, 168–176 (2011).
26.
Low-Density Nanocellular Foams Produced by High-Pressure Carbon Dioxide, RegleroJ.A., DumonM., PintoJ., and Rodríguez-PerezM.A., Macromolecular Materials and Engineering, 296, 752–759 (2011).
27.
Microcellular foaming of polymethylmethacrylate in a batch supercritical CO2 process: Effect of microstructure on compression behavior, Reglero RuizJ.A., ViotP., DumonM., Journal of Applied Polymer Science, 118(1), 320–331 (2010).
28.
“Investigation of the Nanocellular Foaming of Polystyrene in Supercritical CO2 by Adding a CO2-Philic Perfluorinated Block Copolymer”, Reglero RuizJ.A., CloutetE., DumonM., Journal of Applied Polymer Science, 126, 38–45 (2012).
29.
In Situ IR Spectroscopy and Ab Initio Calculations To Study Polymer Swelling by Supercritical CO2, VitouxPauline, TassaingThierry, CansellFrancois, MarreSamuel, and AymonierCyril, J. Phys. Chem. B, 113, 897–905 (2009).
30.
Solubility and Self-Assembly of Amphiphilic Gradient and Block Copolymers in Supercritical CO2, RibautTiphaine, OberdisseJulian, AnnighoferBurkhardt, FournelBruno, SarradeStephane, HallerHeike, Lacroix-DesmazesPatrick, J. Phys. Chem. B, 115, 836–843 (2011).
31.
Solubility of fluorinated homopolymer and block copolymer in compressed CO2, AndréPascal, Lacroix-DesmazesPatrick, TaylorDarlene K., BoutevinBernard, J. of Supercritical Fluids, 37, 263–270 (2006)
32.
Foaming of amorphous polymers and blends in supercritical CO2: Solubility versus block copolymers addition, RegleroJose Antonio, ViotPhilippe, and DumonMichel, Journal of Cellular Plastics, 47, 535–548 (2011).
33.
Two-step micro cellular foaming of amorphous polymers in supercritical CO2, RuizJose Antonio Reglero, Marc-TallonJean, PedrosMatthieu, DumonMichel, J. of Supercritical Fluids, 57, 87–94 (2011).
