Polymer nanocomposite foams

https://pure.rug.nl/ws/files/6693298/2006ProgPolymSciNalawade.pdf

Supercritical carbon dioxide as a green solvent for processing polymer melts: Processing aspects and applications

Preface. Acronyms. 1 Introduction to Flame Retardancy and Polymer Flammability (Sergei V. Levchik). 1.1 Introduction. 1.2 Polymer Combustion and Testing. 1.3 Flame Retardancy. 1.4 Conclusions and Future Outlook. References. 2 Fundamentals of Polymer Nanocomposite Technology (E. Manias, G. Polizos, H. Nakajima, and M. J. Heidecker). 2.1 Introduction. 2.2 Fundamentals of Polymer Nanocomposites. 2.3 Effects of Nanofillers on Material Properties. 2.4 Future Outlook. References. 3 Flame Retardant Mechanism of Polymer-Clay Nanocomposites (Jeffrey W. Gilman). 3.1 Introduction. 3.2 Flame Retardant Mechanism. 3.3 Conclusions and Future Outlook. References. 4 Molecular Mechanics Calculations of the Thermodynamic Stabilities of Polymer-Carbon Nanotube Composites (Stanislav I. Stoliarov and Marc R. Nyden). 4.1 Introduction. 4.2 Background and Context. 4.3 Description of the Method. 4.4 Application to PS-CNT Composites. 4.5 Uncertainties and Limitations. 4.6 Summary and Conclusions. References. 5 Considerations Regarding Specific Impacts of the Principal Fire Retardancy Mechanisms in Nanocomposites (Bernhard Schartel). 5.1 Introduction. 5.2 Influence of Nanostructured Morphology. 5.3 Fire Retardancy Effects and Their Impact on the Fire Behavior of Nanocomposites. 5.4 Assessment of Fire Retardancy. 5.5 Summary and Conclusions. References. 6 Intumescence and Nanocomposites: a Novel Route for Flame-Retarding Polymeric Materials (Serge Bourbigot and Sophie Duquesne). 6.1 Introduction. 6.2 Basics of Intumescence. 6.3 Zeolites as Synergistic Agents in Intumescent Systems. 6.4 Intumescents in Polymer Nanocomposites. 6.5 Nanofillers as Synergists in Intumescent Systems. 6.6 Critical Overview of Recent Advances. 6.7 Summary and Conclusion. References. 7 Flame Retardant Properties of Organoclays and Carbon Nanotubes and Their Combinations with Alumina Trihydrate (Gunter Beyer). 7.1 Introduction. 7.2 Experimental Process. 7.3 Organoclay Nanocomposites. 7.4 Carbon Nanotube Nanocomposites. 7.5 Summary and Conclusions. References. 8 Nanocomposites with Halogen and Nonintumescent Phosphorus Flame Retardant Additives (Yuan Hu and Lei Song). 8.1 Introduction. 8.2 Preparation Methods and Morphological Study. 8.3 Thermal Stability. 8.4 Mechanical Properties. 8.5 Flammability Properties. 8.6 Flame Retardant Mechanism. 8.7 Summary and Conclusions. References. 9 Thermoset Fire Retardant Nanocomposites (Mauro Zammarano). 9.1 Introduction. 9.2 Clays. 9.3 Thermoset Nanocomposites. 9.4 Epoxy Nanocomposites Based on Cationic Clays. 9.5 Epoxy Nanocomposites Based on Anionic Clays. 9.6 Polyurethane Nanocomposites. 9.7 Vinyl Ester Nanocomposites. 9.8 Summary and Conclusions. References. 10 Progress in Flammability Studies of Nanocomposites with New Types of Nanoparticles (Takashi Kashiwagi). 10.1 Introduction. 10.2 Nanoscale Oxide-Based Nanocomposites. 10.3 Carbon-Based Nanocomposites. 10.4 Discussion of Results. 10.5 Summary and Conclusions. References. 11 Potential Applications of Nanocomposites for Flame Retardancy (A. Richard Horrocks and Baljinder K. Kandola). 11.1 Introduction. 11.2 Requirements for Nanocomposite System Applications. 11.3 Potential Application Areas. 11.4 Future Outlook. References. 12 Practical Issues and Future Trends in Polymer Nanocomposite Flammability Research (Alexander B. Morgan and Charles A. Wilkie). 12.1 Introduction. 12.2 Polymer Nanocomposite Structure and Dispersion. 12.3 Polymer Nanocomposite Analysis. 12.4 Changing Fire and Environmental Regulations. 12.5 Current Environmental Health and Safety Status for Nanoparticles. 12.6 Commercialization Hurdles. 12.7 Fundamentals of Polymer Nanocomposite Flammability. 12.8 Future Outlook. References. Index.

Flame retardant polymer nanocomposites

High-pressure fluid-phase equilibria: Experimental methods and systems investigated (2000-2004)

Applications of supercritical CO2 in the fabrication of polymer systems for drug delivery and tissue engineering

The solubility and diffusivity of supercritical carbon dioxide (sc-CO2) in low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), ethylene-ethylacrylate copolymer (EEA) and polystyrene (PS) were measured at temperatures from 150°C to 200°C and pressures up to 12 MPa by using the Magnetic Suspension Balance (MSB), a gravimetric technique for gas sorption measurements. The solubility of CO2 in each polymer was expressed by Henry's constant. The interaction parameter between CO2 and polymer could be obtained from the solubility data, and it was used to estimate the Pressure-Volume-Temperature relationship and the specific free volume of polymer/CO2 mixtures. The diffusion coefficients were also measured by the MSB for each polymer. The resulting diffusion coefficients were correlated with the estimated free volume of polymer/CO2 mixture. Combining Fujita's and Maeda and Paul's diffusion models, a model was newly developed in order to predict diffusion coefficients for the polymers studied. Polym. Eng. Sci. 44:1915–1924, 2004. © 2004 Society of Plastics Engineers.

Measurement and prediction of diffusion coefficients of supercritical CO2 in molten polymers

Using a newly developed high-pressure autoclave, which has two sapphire windows on the walls, we visually observed the batch physical foaming of polymer-clay nanocomposites to understand the effect of nano-sized clay on the initial stage of foaming. With CO 2 as a physical foaming agent, polypropylene-montmorillonite clay nanocomposites were foamed at 150°C. A high-speed digital camera with a microscope could observe the bubble nucleation and bubble growth behavior of the early stage of foaming in situ. The series of micrographs was analyzed in order to investigate the effect of clay content on bubble nucleation and growth. The experiments, together with CO 2 -solubility and diffusivity data, show that the clay enhances bubble nucleation as a nucleation agent and retards the growth of bubbles at the early stage of foaming.

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Visual observation of CO2 foaming of polypropylene‐clay nanocomposites

The densities of two polymer/CO2 single-phase solutions, poly(ethylene glycol) (PEG)/CO2 and polyethylene (PE)/CO2, were measured at temperatures higher than melting temperature of the polymer under CO2 pressures in the range 0–15 MPa using a newly-proposed gravimetric method. A magnetic suspension balance (MSB) was used for the density measurement under the high pressure CO2: A thin disc-shaped platinum plate was submerged in the considered polymer/CO2 single-phase solution in the MSB high-pressure cell. The weight of the plate was measured while keeping CO2 pressure and temperature in the sorption cell at a specified level. Since the buoyancy force exerted on the plate by the polymer/CO2 solution reduced the apparent weight of the plate, the density of the polymer/CO2 solution could be calculated by subtracting the true weight of the plate from its measured weight. Experimental results showed that the density of PE/CO2 solution increased with the increase of CO2 pressure and the density of PEG/CO2 solution decreased with the increase of CO2 pressure. To differentiate the effect of CO2 dissolution in polymer from that of mechanical pressure, the density of polymer/CO2 solution was compared with the density of neat polymer under the given mechanical pressure, which was calculated using the Sanchez–Lacombe equation of state and Pressure–Volume–Temperature data of the polymer. The comparison could elucidate that the dissolution of CO2 in polymer reduced density of both PEG/CO2 and PE/CO2 systems but the degree of CO2 induced-density reduction was different between two polymer/CO2 systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Density measurement of polymer/CO2 single-phase solution at high temperature and pressure using a gravimetric method

The phase behavior of crosslinked polyisoprene rubber (PIR) in CO 2 at temperatures ranging from 293 to 453 K and pressures ranging from 0.1 to 20 MPa were investigated. Visual swelling measurements based on the sample dimensions were performed using a high-pressure view cell. The change of the degree of swelling with time provided a diffusion coefficient of CO 2 in crosslinked PIR. The solubility measurements were carried out by using a magnetic suspension balance (MSB) method. The weight change of the sample in CO 2 under elevated pressure and temperature was converted to solubility taking the buoyancy effect and the degree of swelling into account; the degree of swelling was derived both from the visual swelling measurement and from theoretical estimation on the basis of the Sanchez–Lacombe equation of state. The solubility from the two methods was in good agreement with each other in the range from 8 to 13 MPa.

Eita Funami

Papers

Measurement and prediction of diffusion coefficients of supercritical CO2 in molten polymers

Visual observation of CO2 foaming of polypropylene‐clay nanocomposites

Density measurement of polymer/CO2 single-phase solution at high temperature and pressure using a gravimetric method

Phase behavior of crosslinked polyisoprene rubber and supercritical carbon dioxide

Measurement of CO2-Induced Polymer Swelling and Predictability of Sanchez-Lacombe Equation of State for the Density of Polymer/CO2 Systems