Abstract: Expanded and extruded biodegradable polymer foams are obtained using biodegradable polymers and environmentally benign non-VOC methyl formate as a blowing agent. The blowing agent can be a blend further including at least one co-blowing agent, preferably an environmentally friendly species (e.g., non-VOC), which is either a physical co-blowing agent (e.g. an inorganic agent, a hydrocarbon, a halogenated hydrocarbon, a hydrocarbon with polar, functional group(s), water or any combination thereof), or a chemical co-blowing agent, or combinations thereof. The blowing agent blend can include any combination of methyl formate and one or more co-blowing agents. The polymer foam can include a biodegradable polymer or its blends with other biodegradable polymers or conventional (non-biodegradable) polymers. The methyl formate-based blowing agent blends produce stable foams for various applications, including containers, packaging systems, as well as for insulation and protective cushioning.

Abstract: A nano-cellular polymer foam is disclosed, which has an average pore size from about 10 nanometers to about 500 nanometers; and a foam density that is from about 1 percent to about 50 percent of the bulk density of the material of the nano-cellular foam.

Abstract: The present invention is to solve conventional problems, namely, that when an attempt is made to obtain a thick, in-mold foamed molded article with excellent fusibility between beads formed from an acrylic resin expanded beads, cooling takes an extremely long time and production efficiency is poor, and to provide acrylic resin expanded beads with which an in-mold foamed molded article with excellent fusibility between expanded beads can be manufactured in a short cooling time even with a thick foamed molded article such as a block foamed molded article, and the molding cycle can be improved. The acrylic resin expanded beads of the present invention are expanded beads in which an acrylic resin serves as a base resin, and the bead surfaces have continuous ridges in a mesh pattern.

Abstract: In one aspect, the invention provides a foam thermal interface material comprising a foamed film, the film comprising a blend of polymeric hot melt pressure sensitive adhesive having a number average molecular weight of greater than 25,000 and at least 25 percent by weight of thermally conductive filler, said film having a void volume of at least 5 percent of the volume of said foamed film.

Abstract: Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.

Abstract: A method for forming a fire resistant material is disclosed. The method comprises providing a plurality of expandable beads of a polymeric material. The beads are coated with an exfoliable graphite. The exfoliable graphite is adhered to the beads with a resin having a solubility parameter of the polymeric material. The beads are thereafter caused or allowed to expand and fuse.

Abstract: A plurality of pellets include at least one of a snythetic, biomass, mineral, or polymer based material. The pellets can have a specific gravity of about 0.01 to about 0.3 g/cm3 and are dimensionally stable, substantially dust-free, substantially non-hygroscopic, and resistant to settling and compression.

Abstract: According to the present invention, there is provided expandable beads of a styrene-modified linear low-density polyethylene-based resin comprising a volatile blowing agent and a base resin, the base resin containing more than 50 to 1000 parts by weight of a polystyrene-based resin component relative to 100 parts by weight of a non-crosslinked linear low-density polyethylene-based resin component, wherein the base resin contains less than 2 wt % of a gel component comprising a graft polymer of the polystyrene-based resin component and the low-density polyethylene-based resin component.

Abstract: According to the present invention, there is provided expandable beads of a styrene-modified linear low-density polyethylene-based resin comprising a volatile blowing agent and a base resin, the base resin containing more than 300 parts by weight and less than 1000 parts by weight of a polystyrene-based resin component relative to 100 parts by weight of a non-crosslinked linear low-density polyethylene-based resin component, wherein the base resin contains 2 to 40 wt % of a gel component comprising a graft copolymer of the polystyrene-based resin component and the low-density polyethylene-based resin component.

Abstract: Porous spherical particles of polyamide 11 or polyamide 12 can be produced by an industrially advantageous process which comprises the steps of mixing a polyamide solution of polyamide 11 or polyamide 12 dissolved in a phenol compound and a low molecular weight aliphatic alcohol which is a poor solvent for the polyamides but is well compatible with the phenol compound in the presence of a high molecular weight alkylene glycol to prepare a mixture solution having an initial viscosity of 10 mPa·s or more, and allowing the mixture solution to stand, to precipitate polyamide particles.

Abstract: To provide porous monodispersed particles obtained by preparing, as seed particles, poly(methyl methacrylate) particles or acrylic resin particles comprising 70% by mass or more of methyl methacrylate as a copolymerization component, swelling the seed particles 20 to 80 times the size of the original seed particles by mass using a swelling solution comprising an oil-soluble polymerization initiator and a monomer mixture containing 70% by mass or more of methyl methacrylate and 3 to 8% by mass of divinylbenzene, and polymerizing the monomers. The particles are porous particles with a diameter of the order of micrometers and a narrow particle-size distribution and are monodispersed. Colored monodispersed particles obtained by agglomerating a pigment in the porous monodispersed particles are monodispersed and spherical, and contain a large amount of pigment therein.

Abstract: Thermoplastic particle foams which have cells having a mean cell size in the range from 20 to 500 ?m and in which the cell membranes have a nanocellular or fibrous structure having pore or fiber diameters below 1500 nm, and also processes for producing them.

Abstract: Disclosed is an aromatic polyimide having extremely high stiffness and extremely high gas barrier property, which is prepared from a tetracarboxylic acid component consisting essentially of 25 mol % to 97 mol % of 3,3?,4,4?-biphenyltetracarboxylic acid and 75 mol % to 3 mol % of 4,4?-oxydiphthalic acid based on 100 mol % of the total amount of the tetracarboxylic acid component, and a diamine component consisting essentially of p-phenylenediamine.

Abstract: A method for producing an environment protective foamed thermoplastic resin polymer comprises using an extruder with a helical rod to be driven to rotate. The extruder has a feeding section, a melting section, a mixing section and a heating-shaping section formed therein. The method includes a plurality of steps, in which thermoplastic resin is heated, melted in the melting section and moved into the mixing section, and hollow expansion balls are fed into the extruder to be evenly mixed with the melted thermoplastic resin. Then the hollow expansion balls are slightly heated and inflated, and moved into the heating-shaping section, and then the balls are heated at foaming temperature, foamed and inflated. After being injected through a nozzle, the melted thermoplastic resin and the hollow balls become a foamed thermoplastic resin polymer with a preset thickness and shape.

Abstract: A pre-expanded beads of olefin-modified polystyrene-based resin comprising a pie-expanded beads of a polystyrene-based resin modified with a polyolefin-based resin, wherein a styrene-based monomer forming a polystyrene-based resin in the beads is used in the range of 100 to 1,000 parts by weight relative to 100 parts by weight of a polyolefin-based resin, a bulk density of each bead is 0.012 to 0.20 g/cm3, and an absorbance ratio at 698 cm?1 and 2850 cm?1 (D698/D2850) obtained from an infrared absorption spectrum of each bead surface measured by ATR method infrared spectroscopy is in the range of 0.1 to 2.5.

Abstract: The invention is a method of producing a cross-linked polymeric support having a multimodal pore structure, which comprises providing a degradable initiator molecule; providing an organic phase comprising said initiator molecule, radically polymerizable monomers and a porogen in a solvent; providing an aqueous phase comprising a transition metal catalyst; suspension polymerization of the organic phase by adding a ligand, co-ordinating to the transition metal in the aqueous phase to produce a cross-linked polymeric support having a primary pore structure and comprising initiator molecule; and subjecting the support obtained to degrading conditions to remove the initiator molecule from within the support to produce a cross-linked polymeric support having a secondary pore structure in addition to the primary pore structure.

Abstract: The disclosure pertains to foam of polymers, which can be made by a method for making a polymer foam comprising vacuum or gas-filled compartments by making a solution of 1 to 20% by weight of a polymer in a solvent; adding particles to the a polymer solution; solidifying the polymer wherein the particles are contained by heating, cooling, ageing, or coagulating to obtain a polymer foam or matrix comprising the particles, and obtaining from the polymer matrix the polymer foam containing the compartments; and optionally washing, drying, and/or heating the polymer foam.

Abstract: A method of forming a composition of expanded polylactic acid (PLA) resin beads comprising impregnating PLA resin beads with CO2 and holding the impregnated beads at a temperature and pressure that prevents the beads from foaming while allowing the level of impregnated CO2 to reduce. The method may comprise pre-expanding the beads at a pre-expansion temperature. Promptly following pre-expansion or after a desired storage period, the method may comprise introducing the pre-expanded beads into a mould and further expanding and fusing the beads in the mould by application of a temperature greater than the temperature used for pre-expansion. Preferred moulded products include moulded blocks and shaped moulded products, especially blocks adapted to form packing material. Other preferred moulded products include convenience items such as containers including clamshell containers, pots, boxes, bowls, cups, plates and trays.

Abstract: A foamable polymeric composition can comprise a polymer, a blowing agent cage material, and a blowing agent. The blowing agent cage material is selected from the group consisting of zeolite imidazolate framework, metal organic framework, carbon cage structure, and combinations comprising at least one of the foregoing. In one embodiment, the composition can be formed by mixing the polymer with the blowing agent cage material to form a mixture, introducing a blowing agent to the mixture, and forming the mixture into pellets.

Abstract: An expanded molded article having a void percentage of 5 to 50%, the molded article comprising 50 to 800 parts by weight of styrene-based resin relative to 100 parts by weight of non-crosslinked linear low-density polyethylene-based resin which can be obtained by using a metallocene catalyst, wherein the molded article is obtained by impregnating styrene-modified linear low-density polyethylene-based resin beads with a volatile blowing agent to provide expandable beads, pre-expanding the expandable beads and then subjecting the obtained pre-expanded beads to expansion molding, the styrene-modified linear low-density polyethylene-based resin beads each have the styrene-based resin dispersed in the form of particles, and a diameter of particle is 0.8 ?m or smaller in a surface region within at least 5 ?m from the bead surface and in a center region within a 5 ?m radius from the bead center.

Abstract: An object of the present invention is to provide expanded polyhydroxyalkanoate resin beads which are satisfactory and have biodegradability, the molded product thereof, and process for producing the expanded resin beads. The object can be achieved by expanded poly(3-hydroxyalkaonate) (abbreviated to P3HA) resin beads obtained from a P3HA resin composition comprising: a copolymer which comprises repeating units of one or more kinds represented by the formula (1): [—O—CHR—CH2—CO—] (wherein R is alkyl represented by CnH2n+1, provided that n is an integer of 1-15) and is yielded by a microorganism (this copolymer is P3HA); and an isocyanate compound, and having a melt viscosity of 500 Pa·s or higher when examined under the conditions of a shear rate of 122 sec?1 and a temperature of from Tm1 to Tm2, wherein Tm1 is the melting temperature of the P3HA resin composition and Tm2=Tm1+20° C., provided that Tm2<180° C.

Abstract: Disclosed is a method for production of an expandable polyethylene resin particle having a foaming agent impregnated therein, which comprises polymerizing a styrene monomer or a monomer mixture containing a styrene monomer onto a nuclear particle comprising an ethylene-vinyl acetate copolymer and a linear low-density polyethylene.

Abstract: A method of manufacturing thermosets such as epoxy resins includes adding expandable hollow microspheres, which expand with temperature as shown in the accompanying graph, to the base thermoset components in the liquid phase and applying heat treatment to the mixture so formed causing the micropsheres to expand during or after curing of the thermoset. This results in a toughening mechanism caused by compressive residual stress around the microspheres which significantly increases the specific fracture energy of the epoxy resin.

Abstract: A nano-cellular polymer foam is disclosed, which has an average pore size from about 10 nanometers to about 500 nanometers; and a foam density that is from about 1 percent to about 50 percent of the bulk density of the material of the nano-cellular foam.

Abstract: Process for improving the insulating capacity of expanded vinyl aromatic which comprises: 1) preparing beads of expandable vinyl aromatic polymers containing 1-10% by weight, calculated with respect to the polymer, of an expanding agent englobed in the polymeric matrix and 0.001-25% by weight, calculated with respect to the polymer (a), of an athermanous additive comprising carbon black homogeneously distributed in the polymeric matrix; 2) treating the surface of the beads, before deposition of the coating, with a liquid lubricating agent; and 3) thermally treating the beads with hot air at a temperature ranging from 30 to 60° C.

Abstract: To provide porous monodispersed particles obtained by preparing, as seed particles, poly(methyl methacrylate) particles or acrylic resin particles comprising 70% by mass or more of methyl methacrylate as a copolymerization component, swelling the seed particles 20 to 80 times the size of the original seed particles by mass using a swelling solution comprising an oil-soluble polymerization initiator and a monomer mixture containing 70% by mass or more of methyl methacrylate and 3 to 8% by mass of divinylbenzene, and polymerizing the monomers. The particles are porous particles with a diameter of the order of micrometers and a narrow particle-size distribution and are monodispersed. Colored monodispersed particles obtained by agglomerating a pigment in the porous monodispersed particles are monodispersed and spherical, and contain a large amount of pigment therein.

Abstract: An expandable polystyrene bead production method, which is a two-step process, is disclosed. The method includes obtaining suspendable, homogenous micropellets from a mixed composition prepared by mixing graphite particles with a styrene-based resin and extruding the composition, and carrying out seed polymerization by suspending graphite-containing micropellets in water and adding a styrene-based monomer and an aromatic hydrocarbon having 6 to 10 carbon atoms, and impregnation by adding a blowing agent. The produced expandable polystyrene beads, which contain graphite particles, are considerably low in thermal conductivity. In addition, the expandable polystyrene beads exhibit a little change in the thermal conductivity over time due to the use of the graphite particles, so that the heat insulation property can be sustained for an extended period of time.

Abstract: Disclosed is a method comprising contacting polystyrene with carbon black and expandable microspheres to form a composition, and expanding the microspheres to foam the composition. Also disclosed is a foamed composition comprising polystyrene, carbon black, and expandable microspheres. The inventive polystyrene compositions have improved mechanical properties.

Abstract: Expandable monovinylidene aromatic polymer, e.g., polystyrene, beads are prepared by a suspension polymerization process comprising polymerizing monovinylidene aromatic monomer, e.g., styrene, under suspension polymerization conditions with, based on the weight of the monomer: A. 0.05 to 0.60 percent by weight (wt %) of tricalcium phosphate, B. Greater than 0 to 0.1 wt % of calcium carbonate, C. 0.0002 to 0.005 wt % of co-stabilizer, D. 0.0001 to 0.01 wt % of a low molecular weight polyethylene wax, E. 0.4 to 0.9 wt % of a flame retardant, and F. 2 to 10 wt % of a C3-6 hydrocarbon blowing agent. The expandable beads are converted to foam having a low thermal conductivity by contacting the separated and dried expandable beads at foaming conditions with, based on the weight of the monomer: A. 0.05 to 0.65 wt % of a glyceride comprising units of fatty acids with a C8-26 chain length, and B. 0.005 to 0.30 wt % of a metal stearate.

Abstract: Process for preparing polymer, e.g. polystyrene, particles that may not or may contain a water-retaining agent and that require only a one-step process for incorporating the water-retaining agent. The polymer particles may be prepared via an extrusion process, or a bulk polymerization process wherein a water-retaining agent is blended into the polymer melt. Water is incorporated into the particles by soaking them in hot or cold water or treating the particles with steam for a predetermined time depending on the desired water content in the particles. The water-retaining agent may be starch, zeolite, silica dioxide or poly (N-isopropyl acrylamide) ranging from 0.1% to 10.0% by weight. The particles can be expanded via appropriate means to form pre-expanded or expanded particles in a conventional manner.

Abstract: Expandable granulates having a composition based on vinyl-aromatic polymers, essentially consisting of: 65-99.8% by weight of a copolymer obtained by polymerizing 85-100% by weight of one or more vinyl-aromatic monomers having general formula (I) and 0.15% by weight of an alpha-alkylstyrene; 0-25% by weight, calculated with respect to the polymer (a), of carbon black; at least one of the following products: 0.01-5% by weight of graphite having an average diameter ranging from 0.5 to 50 ?m; 0.01-5% by weight of oxides and/or sulfates and/or lamellar dichalcogenides of metals of groups IIA, IIIA, IIIB, IVB or VIIIB, 0.01-5% by weight of inorganic derivatives of silicon of the lamellar type; 0-5% by weight, calculated with respect to the polymer (a), of a nucleating agent; 1-6% by weight, calculated with respect to the total, of an expanding agent.

Abstract: Process for processing expandable polymer particles e.g. polystyrene (EPS) that eliminates the maturing step between the pre-expander and molding steps. The expandable particles are first over pressurized with gas, e.g. air, carbon dioxide, nitrogen, and mixtures thereof, at a pressure between 500 and 8000 kPa and a temperature between ?20° C. and 130° C. for 15 to 7200 minutes to create a gas pressure in the particles. Using the gas pressure in the particles, pre-expanding the particles with a heating medium, e.g. steam at a temperature between 100° C. and 120° C. and at a pressure ranging above atmospheric pressure and below the gas pressure in said particles, i.e. 50 to 200 kPa for 5 to 120 seconds. The pre-expanded particles are air dried in the pre-expander while holding a positive pressure in the particles; are optionally transferred to a pressure silo; and then are transferred to a molding machine where the gas pressure in the particles is used to form a foam article.

Abstract: Process for preparing polymer, e.g. polystyrene, particles that may not or may contain a water-retaining agent and that require only a one-step process for incorporating the water-retaining agent. The polymer particles may be prepared via an extrusion process, or a bulk polymerization process wherein a water-retaining agent is blended into the polymer melt. Water is incorporated into the particles by soaking them in hot or cold water or treating the particles with steam for a predetermined time depending on the desired water content in the particles. The water-retaining agent may be starch, zeolite, silica dioxide or poly (N-isopropyl acrylamide) ranging from 0.1% to 10.0% by weight. The particles can be expanded via appropriate means to form pre-expanded or expanded particles in a conventional manner.

Abstract: The present invention is to solve conventional problems, namely, that when an attempt is made to obtain a thick, in-mold foamed molded article with excellent fusibility between beads formed from an acrylic resin expanded beads, cooling takes an extremely long time and production efficiency is poor, and to provide acrylic resin expanded beads with which an in-mold foamed molded article with excellent fusibility between expanded beads can be manufactured in a short cooling time even with a thick foamed molded article such as a block foamed molded article, and the molding cycle can be improved. The acrylic resin expanded beads of the present invention are expanded beads in which an acrylic resin serves as a base resin, and the bead surfaces have continuous ridges in a mesh pattern.

Abstract: A process of producing expandable styrene resin particles, wherein in suspension polymerization of styrene monomers, the concentration of oxygen in a reaction vessel is kept low at least in a late stage of the polymerization, and the resulting styrene resin particles are impregnated with an expanding agent before or after completion of the polymerization. Preferably, at a polymerization rate of 60% or higher, the concentration of oxygen in the reaction vessel is kept at 7 volt % or lower. When additional styrene monomers are added during the polymerization, they are added and adsorbed to styrene resin particles in the course of polymerization while the concentration of oxygen is kept low. By this method, the particles whose internal portion has a low molecular weight and surface portion has a high molecular weight are obtained. A foamed article produced from the particles has high strength and a good appearance.

Abstract: The present invention relates to a method of preparing expanded thermoplastic microspheres, comprising charging thermally expandable microspheres into an expansion device comprising rotating feeding means enveloped by a hollow body, and one or more scrapers. The invention further relates to an expansion device for expanding thermoplastic microspheres.

Abstract: A heat-peelable adhesive sheet which comprises a substrate and, formed on at least one side thereof, a heat-expandable layer containing heat-expandable microspheres and an adhesive layer comprising an adhesive substance and in which the substrate has heat resistance and stretchability can be used to cut an adherend so as to form and secure a sufficient space between the resultant cut pieces and can withstand a heat treatment for expanding the heat-expandable layer. Consequently, the adhesive sheet can heighten the operating efficiency and working efficiency in the step of separating and recovering the cut pieces.

Abstract: A heat-peelable adhesive sheet which comprises a substrate and, formed on at least one side thereof, a heat-expandable layer containing heat-expandable microspheres and an adhesive layer comprising an adhesive substance and in which the substrate has heat resistance and stretchability can be used to cut an adherend so as to form and secure a sufficient space between the resultant cut pieces and can withstand a heat treatment for expanding the heat-expandable layer. Consequently, the adhesive sheet can heighten the operating efficiency and working efficiency in the step of separating and recovering the cut pieces.

Abstract: In forming pressure sensitive adhesive microspheres by copolymerizing a non-ionic monomer of an alkyl acrylate or alkyl methacrylate ester of a non-tertiary alcohol and an acid monomer copolymerizable with said non-ionic monomer, an electrolyte is present during the polymerization to promote formation of solid rather than hollow microspheres.

Abstract: Thermo-expansive microcapsules comprising a shell of a polymer produced by polymerizing a mixture of monomers, which comprises (I) a nitrile monomer, (II) a monomer having an unsaturated double bond and carboxyl groups in a molecule, (III) a monomer having two or more of polymerizable double bonds in a molecule, and optionally, (IV) a monomer different from and copolymerizable with the monomers (I), (II) and (III) and a blowing agent encapsulated in the shell. The volume retention of the expanded microcapsules of the thermo-expansive microcapsules is 50% or more after loaded with 15 MPa.

Abstract: A silicone rubber is produced by curing a silicone rubber composition which includes (A) a curable organopolysiloxane composition and (B) at least one hollow organic resin filler whereby the filler forms cells in an open-cell state. The open-cell state gives the silicone rubber good cushioning property and a low compression set.

Abstract: Expanded granules or a moulded article made therefrom, based on semicrystalline propylene polymer comprising, per 100 parts by weight, less than 0.035 parts by weight of volatile compounds and processes for its preparation.

Abstract: Interpolymer resin particles comprised of 20% to 80% by weight polyolefin, e.g. polyethylene and 80% to 20% by weight of an in situ polymerized vinyl aromatic resin, e.g. polystyrene or poly(styrene-butyl acrylate) and forming an interpenetrating network of polyolefin and vinyl aromatic resin particles. The interpolymer particles are impregnated with a volatile hydrocarbon blowing agent, and limonene, e.g. d-limonene, ranging from about 0.1 to about 5 parts, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the interpolymer particles, for improved expandability and a pleasant fragrance.

Abstract: Flame retardant polyolefin pre-expanded particles made of a resin composition comprising a polyolefin resin and a sterically hindered amine ether flame retardant, which can be molded with good moldability to give in-mold foamed articles which have an excellent flame resistance and do not generate harmful gas at the time of burning.

Abstract: The present invention relates to an imaging element comprising at least one image receiving layer and a support, wherein said image receiving layer comprises an open celled microcellular foam. The present invention also relates to an imaging element comprising at least one image receiving layer, an absorbing layer and a support, wherein the absorbing layer comprises an open celled microcellular foam.

Abstract: A foam comprising a propylene copolymer material comprising at least 50 weight percent of units derived from propylene, based on the total propylene copolymer material, and units derived from ethylenically unsaturated comonomers and having a melt flow rate in the range of from 0.5 to 8 g/10 min, a melt strength of at least 5 cN, and a melt drawability of at least 20 mm/s, process for making a foam using such a propylene copolymer material, process for making a foam in the form of thermoplastic foam beads using such a propylene copolymer material, and an expandable composition comprising such a propylene copolymer material.

Abstract: A process of producing expandable styrene resin particles, wherein in suspension polymerization of styrene monomers, the concentration of oxygen in a reaction vessel is kept low at least in a late stage of the polymerization, and the resulting styrene resin particles are impregnated with an expanding agent before or after completion of the polymerization. Preferably, at a polymerization rate of 60% or higher, the concentration of oxygen in the reaction vessel is kept at 7 vol % or lower. When additional styrene monomers are added during the polymerization, they are added and adsorbed to styrene resin particles in the course of polymerization while the concentration of oxygen is kept low. By this method, the particles whose internal portion has a low molecular weight and surface portion has a high molecular weight are obtained. A foamed article produced from the particles has high strength and a good appearance.

Abstract: The present invention provides polypropylene resin pre-expanded particles having small fluctuation in cell diameter and expansion ratio compared to in the past. The pre-expanded particles are obtained by having as a base resin, a polypropylene resin composition comprising polypropylene resin (A), a compound having a triazine skeleton and molecular weight of at most 300 per triazine skeleton unit (B) and as a random component, hydrophilic polymer (C) and inorganic filler (D) and water as the foaming agent. By using the pre-expanded particles, a polypropylene resin in-mold expanded article having decreased unevenness in color and fluctuation in weight can be obtained.

Abstract: Prepare a multimodal thermoplastic polymer foam having a distribution of large and small cells in a substantial absence of water by using a blowing agent stabilizer. Multimodal foams of the present invention have blowing agent stabilizer predominantly located proximate to large cells. The resulting multimodal foams have particular utility as thermal insulating materials.

Abstract: The application relates to a foamable copolymer resin and a process for preparing the same, which comprises firstly adding an organic peroxide initiator, a modifying aid and a foaming agent to a mixed monomers of methyl methacrylate and styrene so as to constitute a homogenous mixture; at the same tine charging a deionized water into a polymerization reactor and adding a dispersant hydroxy ethyl cellulose or hydroxylpropyl cellulose ether with stirring to produce a homogenous mixture, then sealing the reactor and introducing N2 gas to purge the reactor before the above homogenous monomer mixture is added; after the completion of the reaction the residue is washed with water and dewatered and dried, obtaining foamable pellets.