Cellular and multi-cellular polystyrene and polystyrenic foams and methods of forming such foams are disclosed. The foams include an expanded polystyrene formed from expansion of an expandable polystyrene including an adsorbent comprising alumina, wherein the multi-cellular polystyrene exhibits a multi-cellular size distribution. The process for forming a foamed article includes providing a formed styrenic polymer and contacting the formed styrenic polymer with a first blowing agent and an adsorbent comprising alumina to form extrusion polystyrene. The process further includes forming the extrusion styrenic polymer into an expanded styrenic polymer and forming the expanded styrenic polymer into a foamed article.

A surfactant and a method of forming the surfactant having the formula (I) where a is an integer from 1 to 10, b is an integer from 0 to 10, R.sub.1 is —CH.sub.3 or —H, n is an integer from 0 to 20, and R.sub.2 is a moiety selected from the group consisting of (II), (III), (IV), (V), (VI), (VII) or (VIII) where m is an integer from 0 to 4. The surfactant can be used in a method for preparing a rigid polyurethane foam.

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A foamed article is made by infusing the article of thermoplastic elastomer with a supercritical fluid, then removing the article from the supercritical fluid and either (i) immersing the article in a heated fluid or (ii) irradiating the article with infrared or microwave radiation.

The invention relates to a method for impregnating a polymer granulate with a predefined mass of a gaseous propellant. According to the invention, the polymer granulate is arranged inside a pressure vessel and a gaseous propellant is introduced into the inside of the pressure vessel.

The invention refers to a method for producing expanded polymer pellets, which comprises the following steps: melting a polymer comprising a polyamide; adding at least one blowing agent; expanding the melt through at least one die for producing an expanded polymer; and pelletizing the expanded polymer. The invention further concerns polymer pellets produced with the method as well as their use, e.g. for the production of cushioning elements for sports apparel, such as for producing soles or parts of soles of sports shoes. A further aspect of the invention concerns a method for the manufacture of molded components, comprising loading pellets of an expanded polymer material into a mold, and connecting the pellets by providing heat energy, wherein the expanded polymer material of the pellets or beads comprises a chain extender. The molded components may be used in broad ranges of application.

The invention relates to a multi-layered structure intended for producing a packaging article for storage purposes and to a method for producing said structure. The essence of the invention is that a multi-layered composition based on foamed recycled polyethylene terephthalate comprises a printed layer, a layer of foamed recycled polyethylene terephthalate having a density of from 100 kg/m.sup.3 to 900 kg/m.sup.3 and an intrinsic viscosity of from 0.5 dl/g to 1.0 dl/g, and also a layer of polyethylene or a polyethylene copolymer, or a polyethylene terephthalate copolymer. A method for producing a multi-layered composition consists in cleaning polyethylene terephthalate waste, then grinding same into fractions, followed by melting it and subsequently extruding the melt, then producing granulated polyethylene terephthalate, then extruding the granulated polyethylene terephthalate, foaming the melt, subsequently cooling the foamed recycled polyethylene terephthalate, calendering it to a thickness of from 200 μm to 1000 μm.

The present invention provides expanded beads of thermoplastic polyurethane, wherein the thermoplastic polyurethane constituting the expanded beads is an ether-based thermoplastic polyurethane, and a difference (T.sub.1−T.sub.2) between a melting peak temperature (T.sub.1) and a melting peak temperature (T.sub.2) is from 0 to 8° C., wherein the melting peak temperature (T.sub.1) is a melting peak temperature at the time of first heating in a DSC curve obtained by heating the expanded beads from 20° C. to 260° C. at a heating rate of 10° C./min, the melting peak temperature (T.sub.2) is a melting peak temperature at the time of second heating in a DSC curve obtained by cooling from 260° C. to 20° C. at a cooling rate of 10° C./min after the first heating and further heating again from 20° C. to 260° C. at a heating rate of 10° C./min, and the DSC curves are obtained by the heat flux differential scanning calorimetry in conformity with JIS K7121-1987. The expanded beads of thermoplastic polyurethane not only have excellent surface appearance and fusion bonding properties but also have a low shrinkage factor.

The present invention relates to a polyethylene composition comprising a) a polyethylene blend comprising from 95.5% to 99.5 wt % low density polyethylene (LDPE) and from 0.5% to 4.5 wt % high density polyethylene (HDPE), wherein the wt % (% by weight) is based the total amount of low density polyethylene and high density polyethylene in the blend, and b) a mixture of glycerol-mono-stearate and glycerol-mono-palmitate.

Expanded beads are those including a mixture of an olefin-based thermoplastic elastomer and a polyethylene-based resin, wherein a melt flow rate MFR(I) of the olefin-based thermoplastic elastomer is 2-10 g/10 min; a difference ((MFR(II))−(MFR(I))) between a melt flow rate MFR(II) of the polyethylene-based resin and the melt flow rate MFR(I) of the olefin-based thermoplastic elastomer is 1-35 g/10 min; and a content of the polyethylene-based resin in the mixture is 3-40% by weight.

A method for manufacturing semi-conductive polypropylene resin foamed particles of the present invention comprises the steps of: allowing carbon nanotubes to be adsorbed on surfaces of polypropylene resin composition pellets to manufacture carbon nanotube-adsorbed pellets (CNT-PP); and foaming the carbon nanotube-adsorbed pellets (CNT-PP) to form foamed particles.