Properties of calcium carbonate filled and unfilled polystyrene foams prepared using supercritical carbon dioxide

Abstract

Foaming behaviors of four polystyrenes (PSs) filled and unfilled with various amounts of CaCO 3 using supercritical carbon dioxide were investigated. The PSs include three general purpose grades with different molecular weights (different melt index) and one high impact grade. By adjusting foaming conditions, foam density was determined for each investigated sample. In general, the sample with a lower molecular weight (i.e. higher melt index) yielded a lower foam density for the three general purpose PSs. With the addition of CaCO 3 filler, foam density would increase. The inclusion of rubber in high impact PS was found to complicate its foaming behavior. A qualitative correlation between various types of filled/unfilled PSs and foam density was found in a certain range. An optimum foaming temperature range was required to obtain low foam density for each sample. The corresponding change in matrix modulus by employing various PSs and various filler contents apparently affected the resulting foam density. Although several factors were involved in foaming conditions, the addition of CaCO 3 filler played a significant role in reducing cell size and increasing cell density of the PSs foams investigated.

Cell evolution and compressive properties of styrene–butadiene–styrene toughened and calcium carbonate reinforced polystyrene extrusion foams with supercritical carbon dioxide

“…With respect to the microcellular foaming, CaCO 3 is a commonly used nucleation agent that can induce cell nucleation and improve cell density during the foaming process. This effect has been reported in PS SC‐CO 2 foaming . However, there have been no reports on the foaming behavior of the PS/SBS/CaCO 3 ternary system.…”

Controlling Foam Morphology of Poly(methyl methacrylate) via Surface Chemistry and Concentration of Silica Nanoparticles and Supercritical Carbon Dioxide Process Parameters

“…Recent advances in processing of polymer nanocomposite foams enabled new application areas in hydrogen storage [5], electromagnetic shielding [6], and sensing technology [7]. Various polymers are being used in foam applications such as polyurethane, polystyrene, polyethylene, polypropylene, poly(vinyl chloride), polycarbonate, and poly(methyl methacrylate) [8][9][10][11][12][13][14] as well as specialty polymers.…”

“…The addition of inorganic nanoparticles, which act as nucleating agents, induces heterogeneous nucleation and provides a large number of nucleation sites. Furthermore, the presence of micro-or nanosized fillers dramatically decreases the energy barrier for cell nucleation compared to that required for homogeneous nucleation [9,13,16,17]. Existing models based on classical nucleation theories sometimes fail to explain the nucleation satisfactorily.…”

Preparation and characterization of poly(ε‐caprolactone)/calcium carbonate nanocomposites and nanocomposite foams

“…Polymer foams reinforced by fillers such as fibers, clay, talc, CaCO 3 , etc. have been studied and reported [5–9]. Among these fillers, CaCO 3 is of most commonly used mainly for its availability in readily usable form and low cost [10].…”

“…It was reported that CaCO 3 could improve the mechanical property of the matrix, and therefore provokes increased mechanical property of polymer foams [7, 10, 11]. Furthermore, CaCO 3 can also increase the melt viscosity of matrix and acts as bubble nucleating agent, which is conducive to foaming [6, 12]. Therefore, polymer foams filled with CaCO 3 have been extensively studied [6, 7, 12–14].…”