Nano-structured, semicrystalline polymer foams

✍ Scribed by G. Beaucage; J. H. Aubert; R. R. Lagasse; D. W. Schaefer; T. P. Rieker; P. Erlich; R. S. Stein; S. Kulkarni; P. D. Whaley

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 937 KB
• Volume: 34
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(199612)34:17<3063::aid-polb18>3.0.co;2-5

✦ Synopsis

Semicrystalline polymers gelled from thermally quenched semidilute solutions can, in some cases, be supercritically dried to produce nano-structured foams of exceedingly high specific surface area. This article investigates the nano-morphology of these semicrystalline foams. The common morphological feature that these systems display in small-angle scattering can be described by uncorrelated lamellar platelets. The morphological details, which can be obtained using microscopy and small-angle scattering, indicate that these low-density systems occupy a morphological niche between polymeric crystallites from dilute solutions, and spherulitic crystals derived from concentrated solutions and melts. Because these crystalline morphologies occur in concentration ranges between dilute and concentrated, they may offer simple insight into the mechanisms available for distortion of ideal, dilute-solution-derived crystallites as polymer concentration is increased. Several mechanisms for the observed distortions are proposed.