Thermoplastic polyurethane/clay nanocomposite foam made by batch foaming

Abstract

In this study, the foaming of nonwoven fabrics and bulk polymers was investigated. Four different polymers that are commonly used for textiles including polyethylene terephthalate, thermoplastic polyurethane, thermoplastic polyether ester elastomer and polypropylene were foamed by batch foaming. Among the polymers, thermoplastic polyurethane seems to be the most promising material since it possesses the highest cell density and smallest cell size. In addition, nanoclay was added to thermoplastic polyurethane to promote cell nucleation and to increase the cell density. The results showed that well dispersed nanoclay in thermoplastic polyurethane served as an excellent nucleation agent and the cell structure was improved. The cell size of thermoplastic polyurethane nanocomposite foam decreased to 1 µm while the cell density increased to 3 × 1011 cells/cm3.

Preparation of microcellular thermoplastic polyurethane (TPU) foam and its tensile property

“…The microcellular TPU foam was prepared by using batch foaming technique . The compression‐molded TPU sheet was placed into a stainless steel chamber with desired pressure (3.5 MPa) and temperature (25°C) for 12 h to ensure the equilibrium adsorption of CO 2 .…”

“…Due to above‐mentioned advantages, CO 2 has been adopted as the blowing agent to acquire fiber shape, bead shape, and bar shape TPU foams . While these above noted foaming processes were mainly used to investigate the effects of processing parameter and blowing agent on the cell morphology.…”

Influence of cell type and skin-core structure on the tensile elasticity of the microcellular thermoplastic polyurethane foam

“…In fact, researchers have investigated the foaming behavior of TPU or TPU composite by the solid state foaming, extrusion foaming, and injection molding foaming. [17][18][19][20][21] Consequently, closed-cell TPU foams with various shapes such as film, bead and sheet have been prepared. 22 Furthermore, phase inversion is a method to fabricate the open-cell TPU foam in which the concentration of TPU solution is an important parameter to adjust the density of material.…”

Preparation of fluorescent thermoplastic polyurethane microcellular foam films blown by supercritical CO2

“…Recently, the microcellular foaming using physical blowing agent was verified being successful for TPU, where the obtained TPU foam exhibits tiny cell size, uniform cell structure distribution, and high expansion ratio. [12][13][14][15][16][17][18][19][20][21][22] A commercial example of TPU foaming has been developed by BASF and Adidas, 23,24 where TPU bead foams are prepared by a pressure autoclave or a continuous foam extrusion with underwater pelletization using pentane or butane as the blowing agent, the as-received TPU bead foams are steam-molded into a midsole of running shoe. 25 FP can endow TPU with rich color, which makes colored TPU popular in many decorative usages.…”