Supercritical Transitiometry of Polymers

• Published in: Analytical chemistry (Washington) 1998-06, Vol.70 (11), p.2327-2330
• Main Authors: Randzio, Stanisław L, Grolier, Jean-Pierre E
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemistry; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymers; Properties and characterization; Structure, morphology and analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac9800107

Employing supercritical fluids (SCFs) during polymers processing allows the unusual properties of SCFs to be exploited for making polymer products that cannot be obtained by other means. A new supercritical transitiometer has been constructed to permit study of the interactions of SCFs with polymers during processing under well-defined conditions of temperature and pressure. The supercritical transitiometer allows pressure to be exerted by either a supercritical fluid or a neutral medium and enables simultaneous determination of four basic parameters of a transition, i.e., p, T, Δtr H and Δtr V. This permits determination of the SCF effect on modification of the polymer structure at a given pressure and temperature and defines conditions to allow reproducible preparation of new polymer structures. Study of a semicrystalline polyethylene by this method has defined conditions for preparation of new microfoamed phases with good mechanical properties. The low densities and microporous structures of the new materials may make them useful for applications in medicine, pharmacy, or the food industry, for example.