Foaming strategies for bioabsorbable polymers in supercritical fluid mixtures. Part II. Foaming of poly(?-caprolactone-co-lactide) in carbon dioxide and carbon dioxide + acetone fluid mixtures and formation of tubular foams via solution extrusion |
| |
| Affiliation: | 1. Université de Toulouse, UPS, INSA, LMDC (Laboratoire Matériaux et Durabilité des Constructions), 135,avenue de Rangueil, F-31 077 Toulouse Cedex 04, France;2. Université de Toulouse, INPT, UPS, CNRS, Laboratoire de Génie Chimique, 4, Allée Emile Monso, 31432 Toulouse, France;3. Andra, 1-7, rue Jean-Monet, 62298 Châtenay-Malabry, France;1. Center for Materials Architecturing, Korea Institute of Science and Technology, Seoul, 027 92, Republic of Korea;2. Department of Physics, Changwon National University, Changwon, 511 40, Republic of Korea;3. Department of Physics, Pukyong National University, Busan, 485 13, Republic of Korea;4. Department of Materials Science and Engineering, Silla University, Busan, 46958, Republic of Korea;5. Department of Physics, Dongeui University, Busan, 473 40, Republic of Korea;6. Department of Nanomaterial Science and Engineering, University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea;1. Department of Chemical and Biomolecular Engineering, Universidad de Cantabria, Av. Los Castros s/n., 39005 Santander, Spain;2. Department of Chemical Engineering, Universidad de Castilla-La Mancha, Av. Camilo Jose Cela 12, 13071 Ciudad Real, Spain;1. Laboratoire de Génie Chimique, Université de Toulouse: INPT, UPS, CNRS, 4, Allée Emile Monso, F-31030 Toulouse, France;2. Laboratoire Matériaux et Durabilité des Constructions, Université de Toulouse: UPS, INSA, 135, avenue de Rangueil, F-31 077 Toulouse Cedex 04, France;3. Andra, 1-7, rue Jean-Monnet, 92298 Châtenay-Malabry, France;1. Department of Chemistry and Materials Engineering, Changshu Institute of Technology, Changshu, 215500, China;2. Department of Materials Science and Engineering, University of California at Berkeley, CA, 94720, United States;3. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, 211106, China |
| |
| Abstract: | This paper reports on the foaming of poly(?-caprolactone-co-lactide) in carbon dioxide and carbon dioxide + acetone mixtures. Experiments were carried out in specially designed molds with porous metal surfaces and fluid circulation features to generate foams with uniform dimensions at 60, 70 and 80 °C at pressures in the range 7–28 MPa. Depending upon the conditions, foams with pores in the range from 5 to 200 μm were generated. Adding acetone to carbon dioxide improved the uniformity of the pores compared to foams formed by carbon dioxide alone. In addition, a unique high-pressure solution extrusion system was designed and used to form porous tubular constructs by piston-extrusion of a solution from a high-pressure dissolution chamber through an annular die into a second chamber maintained at controlled pressure/temperature and fluid conditions. Long uniform porous tubular constructs with 6 mm ID and 1 mm wall thickness were generated with glassy polymers like poly(methyl methacrylate) by extruding solutions composed of 50 wt% polymer + 50 wt% acetone, or 25 wt% polymer + 10% acetone + 65% carbon dioxide at 70 °C and 28 MPa. Pores were in the 50 μm range. The feasibility of forming similar tubular constructs were demonstrated with poly(?-caprolactone-co-lactide) as well. Tubular foams of the copolymer with interconnected pores with pore sizes in the 50 μm range were generated by extrusion of the copolymer solution composed of 25 wt% polymer + 10 wt% acetone + 65 wt% carbon dioxide at 70 °C and 28 MPa. Reducing the acetone content in the solution led to a reduction of pore sizes. Comparisons with the foaming behavior of the homopolymer poly(?-caprolactone) that were carried out in the molds with porous metal plates show that the foaming behavior of the copolymer is more akin to the foaming behavior of the caprolactone homopolymer component. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
