The present application relates to a chain extender masterbatch for PET extrusion foaming, preparation method therefor, and a use thereof. The masterbatch is mainly prepared by the following components in parts by weight: 5-30 parts of PMDA, 25-90 parts of PBT, 5-70 parts of POE+POE-g-GMA, in which POE accounts for 0-85% of POE+POE-g-GMA by weight; a melting temperature of PBT is 170-225° C. The preparation method includes melting and mixing the above components at a melting temperature of 180-230° C. and a screw speed of 100-500 rpm, and air cooling strand granulating or air cooling die face granulating. The masterbatch can be used in foaming processes of fiber grade PET, film grade PET, bottle grade PET, engineering plastic grade PET and recycled PET.

Foamed articles including a foamed thermoplastic elastomeric material, methods of making the articles, and methods for manufacturing articles of footwear, apparel, and athletic equipment incorporating the articles are provided. One exemplary method for making a foamed article comprises placing an article comprising a foamable fibrous element and carbon dioxide in a vessel, the foamable fibrous element comprising a plurality of filaments, fibers, and/or yarns, wherein each member of the plurality comprises a foamable material; maintaining the vessel at a first pressure and first temperature at which the carbon dioxide is a liquid and carbon dioxide is soluble in the foamable material; optionally exposing the infused article to a second temperature and second pressure; and subjecting the article to a third pressure and third temperature at which the infused carbon dioxide phase transitions to a gas, thereby expanding the foamable material into a foamed material and forming the foamed article.

Described herein are polyamide foam particles including a polymer mixture including: (A) from 25 to 95 wt.-% of at least one polyamide, which is different from a copolyamide (B); and (B) from 5 to 75 wt.-% of at least one copolyamide prepared by polymerizing the following components: (B1) from 15 to 84 wt.-% of at least one lactam; and (B2) from 16 to 85 wt.-% of monomer mixture (M) including; (M1) at least one C.sub.32-C.sub.40 dimer acid; and (M2) at least one C.sub.4-C.sub.12 diamine; where the sum of the components (B1) and (B2) are 100 wt.-%. Also described herein is a process for preparing such polyamide foam particles and polyamide particle foam moldings obtainable by steam-chest molding.

A molded foam that can be easily taken out of split mold blocks is provided. According to an aspect of the present disclosure, a molded foam (1) is obtained by clamping, with split mold blocks, foamed resin obtained by melting and kneading a polyethylene-based resin, wherein the molded foam (1) has a MFR (190° C., g/10 min) of less than 0.8, or the polyethylene-based resin has a MFR (190° C., g/10 min) of not more than 1.0.

The invention relates to a thermally insulated conduit pipe, comprising at least one medium pipe, at least one thermal insulation arranged around the medium pipe, and at least one outer jacket arranged around the thermal insulation, wherein the outer jacket possibly comprises a barrier made of plastic, and wherein the thermal insulation comprises a foam, the cell gas of which contains at least 10 vol % HFOs. Such conduit pipe has good insulating behavior, good environmental balance, and is easily producible.

Foamed articles including a foamed thermoplastic elastomeric material, methods of making the articles, and methods for manufacturing articles of footwear, apparel, and athletic equipment incorporating the articles are provided. One exemplary method for making a foamed article comprises placing an article comprising a foamable material and carbon dioxide in a vessel, the foamable material; maintaining the vessel at a first pressure and first temperature at which the carbon dioxide is a liquid and carbon dioxide is soluble in the foamable material; optionally exposing the infused article to a second temperature and second pressure; and subjecting the article to a third pressure and third temperature at which the infused carbon dioxide phase transitions to a gas, thereby expanding the foamable material into a foamed material and forming the foamed article.

A material for making an underlayment of a floor includes a thermoplastic polymer that has a thickness and a microstructure. The microstructure includes a plurality of closed cells, each cell containing a void and each cell having a maximum dimension extending across the void within the cell that is less than or equal to 200 micrometers long. The microstructure also includes a density that is greater than or equal to 0.18 grams per cubic centimeter.

A resin sheet includes the porous structure. The porous structure is configured to adjust transmission of a millimeter wave. The porous structure has a relative permittivity varying in a thickness direction of the resin sheet such that a difference between average relative permittivities in two adjacent layer portions is a predetermined value or less, the layer portions each having a particular thickness smaller than a wavelength of the millimeter wave. The porous structure includes a boundary portion being one of the layer portions, the boundary portion having a maximum average relative permittivity. The relative permittivity increases in stages from end portions of the porous structure toward the boundary portion, the end portions being defined in the thickness direction of the resin sheet.

A method for preparing a thermoplastic polyurethane elastomer material with micro air holes is provided. The method comprises the following steps: (1) is feeding liquid raw materials such as diisocyanate molecules and solid additives into a double-screw reactor to trigger a polymerization type chain extension reaction and then obtain a macromolecular weight hot melt. (2) is pushing the macromolecular weight hot melt into a mixing extruder and allowing the reaction to continue to obtain a macromolecular thermoplastic polyurethane melt. (3) is continuously adding the obtained macromolecular thermoplastic polyurethane melt together with polymer particles into a foaming extruder, and extruding the high-pressure hot melt from a mold head into an underwater granulation chamber. (4) is delivering the particles obtained after granulation into a separator by process water via a multi-stage pressure-release process water pipeline, separating, screening and drying the required particles to obtain the target product.

An expanded beads molded article containing a block copolymer of a polyethylene block and an ethylene-α-olefin copolymer block and having a density of 150 kg/m.sup.3 or more and 500 kg/m.sup.3 or less and a tensile strength of 0.5 MPa or more.