Premium
Microcellular foaming of polymethylmethacrylate in a batch supercritical CO 2 process: Effect of microstructure on compression behavior
Author(s) -
Reglero Ruiz Jose Antonio,
Viot Philippe,
Dumon Michel
Publication year - 2010
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.32351
Subject(s) - materials science , composite material , supercritical fluid , cabin pressurization , microstructure , split hopkinson pressure bar , micrometer , cell size , strain rate , thermodynamics , physics , biology , optics , microbiology and biotechnology
Microcellular foaming of reinforced core/shell Polymethylmethacrylate (PMMA) was carried out by means of supercritical CO 2 in a single‐step process. Samples were produced using a technique based on the saturation of the polymer under high pressure of CO 2 (300 bars, 40°C), and cellular structure was controlled by varying the depressurization rate from 0.5 bar/s to 1.6 × 10 −2 bar/s leading to cell sizes from 1 μm to 200 μm, and densities from 0.8 to 1.0 g/cm 3 . It was found that the key parameter to control cell size was depressurization rate, and larger depressurization rates generated bigger cell sizes. On the other hand, variation of the density of the samples was not so considerable. Low rate compression tests were carried out, analyzing the dependence of mechanical parameters such as elastic modulus, yield stress and densification strain with cell size. Moreover, the calculation of the energy absorbed for each sample is presented, showing an optimum of energy absorption up to 50% of deformation in the micrometer cellular range (here at a cell size of about 5 μm). To conclude, a brief comparison between neat PMMA and the core/shell reinforced PMMA has been carried out, analyzing the effect of the core/shell particles in the foaming behavior and mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010