This invention relates to a foaming composition, comprising at least one ethylene-vinyl acetate (EVA) copolymer; at least one foaming agent; at least one peroxide compound; at least one polyamine; at least one crosslinking enhancer; at least one primary antioxidant; and at least one secondary antioxidant; the content of the crosslinking enhancer is from 0.1 to 3% by weight based on the total weight of the composition. A foaming article cured from the foaming composition under the temperature range of 80 to 120° C. according to the present invention exhibits high initial volume expansion ratio at the baking window from 130 to 200° C. and shows excellent stability after storage.

Expanded polypropylene beads are prepared from composite particles using a high-temperature and high-pressure kettle type foaming method. The composite particles include a core layer and a skin layer. The core layer includes one or more of the following components, for example in percentage by mass: 20-40% of polypropylene A, 60-80% of polypropylene B, 0-20% of polypropylene C and 0-10% of a thermal-conductive additive. The skin layer includes one or more of the following components, for example in percentage by mass: 40-80% of polypropylene D and 20-60% of polypropylene E. The composite particles are of a multi-layer structure with the skin layer covering the core layer. A resin of the skin layer is easy to sinter at low temperature and in compatibility with a main substrate resin of the core layer. The core layer resin adopts a selected mixture, which promotes molding expansibility.

Expanded polypropylene beads are prepared from composite particles using a high-temperature and high-pressure kettle type foaming method. The composite particles include a core layer and a skin layer. The core layer includes one or more of the following components, for example in percentage by mass: 20-40% of polypropylene A, 60-80% of polypropylene B, 0-20% of polypropylene C and 0-10% of a thermal-conductive additive. The skin layer includes one or more of the following components, for example in percentage by mass: 40-80% of polypropylene D and 20-60% of polypropylene E. The composite particles are of a multi-layer structure with the skin layer covering the core layer. A resin of the skin layer is easy to sinter at low temperature and in compatibility with a main substrate resin of the core layer. The core layer resin adopts a selected mixture, which promotes molding expansibility.

Expanded polypropylene beads comprising a polypropylene composition (C) having: a) a melt flow rate (MFR2) in the range from 1.5 to 15.0 g/10 min; b) a melting temperature (Tm) in the range from 135 to 158° C.; and c) a loss tangent (tan δ) in the range of 2.00 to 4.00 wherein the polypropylene composition (C) comprises more than 90.0 wt.-%, of a long chain branched copolymer of propylene (c-PP) comprising up to 8.0 wt.-% of comonomer(s) selected from ethylene and C.sub.4 to C.sub.10 alpha olefins, a method for the preparation of said beads, in addition to a method of forming molded articles from said beads, and the molded articles obtained thereby.

Expanded polypropylene resin particles include a polypropylene resin as a base material resin, wherein the polypropylene resin has a flexural modulus of 750 MPa to 1100 MPa. The flexural modulus and a melting point of the expanded polypropylene resin particles satisfy Expression (1): [Flexural modulus (MPa)]<31.19×[Melting point (° C.)]−3500, wherein the melting point of the expanded polypropylene resin particles is a melting point of 141.5° C. to 150.0° C. in a second differential scanning calorimetry (DSC) curve of a second temperature increase, the second DSC curve being obtained when the expanded polypropylene resin particles are heated from 40° C. to 220° C. at a temperature increase rate of 10° C./min in a first temperature increase, then cooled from 220° C. to 40° C. at a temperature decrease rate of 10° C./min, and heated again from 40° C. to 220° C. at a temperature increase rate of 10° C./min in the second temperature increase.

Expanded polypropylene resin particles include a polypropylene resin as a base material resin, wherein the polypropylene resin has a flexural modulus of 750 MPa to 1100 MPa. The flexural modulus and a melting point of the expanded polypropylene resin particles satisfy Expression (1): [Flexural modulus (MPa)]<31.19×[Melting point (° C.)]−3500, wherein the melting point of the expanded polypropylene resin particles is a melting point of 141.5° C. to 150.0° C. in a second differential scanning calorimetry (DSC) curve of a second temperature increase, the second DSC curve being obtained when the expanded polypropylene resin particles are heated from 40° C. to 220° C. at a temperature increase rate of 10° C./min in a first temperature increase, then cooled from 220° C. to 40° C. at a temperature decrease rate of 10° C./min, and heated again from 40° C. to 220° C. at a temperature increase rate of 10° C./min in the second temperature increase.

VDF-co-(TFE or TrFE) polymers having a molecular weight of at least about 1,000,000 g/mol and a melt temperature less than about 240° C. The VDF copolymer contains at least about 50 mol % VDF monomer and may include an amount of at least one other monomer. The VDF copolymer may be used to form a membrane that has a node and fibril structure. The membrane has a percent porosity of at least 25%. A VDF-co-(TFE or TrFE) polymer membrane may be formed by lubricating the VDF copolymer, subjecting the lubricated polymer to pressure at a temperature below the melting point of the VDF copolymer to form a preform material, and expanding the preform material at a temperature below the melting temperature of the VDF copolymer. Dense VDF copolymer articles, filled VDF copolymer membranes, and VDF copolymer fibers are also provided.

VDF-co-(TFE or TrFE) polymers having a molecular weight of at least about 1,000,000 g/mol and a melt temperature less than about 240° C. The VDF copolymer contains at least about 50 mol % VDF monomer and may include an amount of at least one other monomer. The VDF copolymer may be used to form a membrane that has a node and fibril structure. The membrane has a percent porosity of at least 25%. A VDF-co-(TFE or TrFE) polymer membrane may be formed by lubricating the VDF copolymer, subjecting the lubricated polymer to pressure at a temperature below the melting point of the VDF copolymer to form a preform material, and expanding the preform material at a temperature below the melting temperature of the VDF copolymer. Dense VDF copolymer articles, filled VDF copolymer membranes, and VDF copolymer fibers are also provided.

An expanded polyolefin resin particle is obtained by expanding a polyolefin resin particle using water and/or an inorganic gas as a foaming agent. The polyolefin resin particle includes a polyolefin resin, a product obtained by heating and kneading a mixture, and a water absorbing substance, wherein the mixture includes a first polypropylene resin, a polypropylene wax, a polyorganosiloxane including at least one silicon-atom-bound radical polymerizable functional group per molecule, and an organic peroxide.

An expanded polyolefin resin particle is obtained by expanding a polyolefin resin particle using water and/or an inorganic gas as a foaming agent. The polyolefin resin particle includes a polyolefin resin, a product obtained by heating and kneading a mixture, and a water absorbing substance, wherein the mixture includes a first polypropylene resin, a polypropylene wax, a polyorganosiloxane including at least one silicon-atom-bound radical polymerizable functional group per molecule, and an organic peroxide.