KR20090048432A - Polymer foams containing multi-functional layered nano-graphite - Google Patents

Abstract

The present invention relates to extruded polystyrene foams containing nano graphite as a process additive for improving the physical properties of thermal insulation products, in particular foamed products.

Description

POLYMER FOAMS CONTAINING MULTI-FUNCTIONAL LAYERED NANO-GRAPHITE}

This application is a partial continuing application of US Patent Application No. 11 / 026,011, filed December 31, 2004.

The present invention relates to rigid foamed polymeric boards containing nano-graphite. More specifically, it relates to rigid foamed polymeric boards in which nanographite is added to provide advantages as processing aids, R-value enhancers, UV radiation stability enhancers, dimensional stability enhancers, mechanical strength enhancers, and fire retardants. The added nano graphite is also added to control the cell morphology, to reduce foam surface static, and to function as an internal lubricant in the foaming treatment.

The utility of rigid foamed polymeric boards is well known in various fields. For example, polymeric foam boards are widely used to insulate structural members of buildings.

In the past, infrared attenuating agents (IAAs) such as carbon black powder amorphous carbon, graphite, and titanium dioxide minimize the thermal conduction of materials (maximum R-value) to maximize thermal insulation for a given thickness. To be used as filler in polymeric foam boards. R-values are defined as commercial units used to measure the effect of thermal insulation. Insulation is a material made of a sheet that interferes with the conduction of thermal energy. Its thermal conductivity is measured, in traditional units, by the conducted energy (Btu), thickness (inch) / hour (hr), area (ft ² ), and temperature difference (° F) between two sides of the material. The R-value of the insulation is defined as thermal conductivity per inch. R is an abbreviation for a complex unit combination of time (hr) · ft ² · ℉ / Btu. In SI units, R value 1 is 0.17611 m 2 / Kelvin temperature (m 2 · K / W).

Heat transfer through the insulation can occur through solid conduction, gas conduction, radiation and convection. Total thermal resistance (R-value), R is a measure of the resistance of the heat transfer and is determined by R = t / k (t = thickness).

Rigid foamed plastic boards are widely used as insulation in various fields. It is highly desirable to improve thermal conductivity without increasing the density and / or thickness of the foamed article. In particular, the architectural community requires a foam board less than 1.8 "thick with a thermal resistance value of R = 10 in a hollow wall configuration to maintain a cavity gap of at least 1".

It is also desirable to improve UV stability, particularly in exterior wall insulation finishing systems (EIFS), and in highways and subways where the surface of polymer foam boards, usually at work sites, are exposed to long term sunlight.

Typical low density foams have very thin cell wall thicknesses of 0.2 to 6 microns. In particular, to reinforce the adiabatic R-value, a target cell wall thickness of less than about 1 micron is required.

Therefore, there is a need for graphite that has at least one dimension—usually equal to the thickness of graphite in plate-shaped graphite, usually on the nano scale, ie less than 0.1 micron or 100 nanometers.

An object of the present invention is a low density extruded polymer foam containing nano graphite having good processing properties and improved foam physical properties including thermal conductivity, ultraviolet (UV) radiation resistance, dimensional stability, mechanical strength, flame propagation rate and smoke density. It is an object to provide a process for forming a.

The present invention relates to foam insulation products and processes for making products such as extruded polystyrene foams containing nanographite as process additives for improving physical properties such as insulation and compressive strength. During foaming, the nanographite acts as nucleating agent and lubricant and its sliding action facilitates the flow of molten polymer in the extruder and provides a smooth surface to the foam board. In addition, nano graphite reduces the amount of idle present during the foaming process by the increased electrical conductivity of the skin of the nano graphite polymer foam board. Nano graphite in foamed products also acts as a UV stabilizer and gas barrier in the final product.

It is an object of the present invention to provide rigid polymer foams containing nanographite which represent the total compound affecting foam properties, including improved thermal insulation (increased R-value) and ultraviolet (UV) stability for a given thickness and density. To produce.

It is another object of the present invention to produce rigid polymer foams containing nano graphite having retained or improved compressive strength, thermal dimensional stability and fire resistance.

Another object of the present invention is to provide nano graphite in rigid polymer foams which also act as process additives to control the cell morphology during the foaming treatment, reduce the idle and provide lubrication.

Another object of the present invention is to further lower the price of polymeric foam products in a simple and economical way, such as using nanographite as an inexpensive, functional dye.

The foregoing and other advantages of the present invention will become apparent from the following description of one or more preferred embodiments of the invention described in detail and illustrated in the accompanying drawings. It is contemplated that changes in procedure, structural features, and arrangement of components can be made by those skilled in the art without departing from the scope of the present invention or at the expense of any benefit.

1 is a graph showing the density versus compression coefficient of polystyrene foam and polystyrene foam containing nanographite.

FIG. 2 is a graph rheologically comparing pure polystyrene foams to polystyrene foams containing nanographite. FIG.

3 is a scanning electron microscope (SEM) image of the foam cell of the present invention.

4 is a scanning electron microscope image of foam cell walls and struts.

5 is a graph comparing polystyrene foam boards to nano graphite / polystyrene boards when both the polystyrene foam boards and the nano graphite / polystyrene boards of the present invention are exposed to UV radiation.

This object is achieved through the development of polymer foams containing nano graphite to control cell morphology and act as gas diffusion barriers. Foams acting as infrared attenuators and cell nucleating agents exhibit improved thermal insulation (R-value). The nano graphite of the foam acts as an internal lubricant during the foaming treatment and makes it possible to release the surface idle during the foaming treatment. Foams of the invention containing nano graphite also have increased dimensional stability. Aesthetically, the foams of the invention have a glossy surface and are silver in color.

The present invention relates in particular to the manufacture of rigid, closed cell, polymeric foam boards prepared by extrusion treatment with nano graphite, at least one blowing agent and other additives.

Hard foamed plastic materials include polyolefins, polyvinylchlorides, polycarbonates, polyetherimides, polyamides, polyesters, polyvinylidenechlorides, polymethylmethacrylates, polyurethanes, polyureas, phenol formaldehydes, polyisocyanurates, It may be any such material suitable for making polymer foams including phenolics, their copolymers and terpolymers, thermoplastic polymer mixtures, rubber modified polymers and the like. Suitable polyolefins include polyethylene and polypropylene, and ethylene copolymers.

Preferred thermoplastic polymers include alkenyl aromatic polymer materials. Suitable alkenyl aromatic polymer materials include copolymers of alkenyl aromatic monomers and ethylenically unsaturated comonomers copolymerizable with alkenyl aromatic compounds. Alkenyl aromatic polymer materials may further comprise small amounts of non-alkenyl aromatic polymers. The alkenyl aromatic polymer material may be any of the foregoing with at least one alkenyl aromatic monomer, at least one alkenyl aromatic copolymer, a mixture of at least one respective alkenyl aromatic monomer and copolymer, or a non-alkenyl aromatic polymer. It may be included alone in the mixture.

Suitable alkenyl aromatic polymers include polymers derived from alkenyl aromatic compounds such as styrene, alphamethylstyrene, ethylstyrene, vinyl benzene, vinyl toluene, chlorostyrene, and bromostyrene. Preferred alkenyl aromatic polymers are polystyrenes. Small amounts of monoethylenically unsaturated compounds, ionomer derivatives and C _4-6 dienes such as C _2-6 alkyl acids and esters may be copolymerized with alkenyl aromatic compounds. Examples of copolymerizable compounds include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, itaconic acid, acrylonitrile, maleic anhydride, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate , Methyl methacrylate, vinyl acetate and butadiene.

Preferred structures comprise substantially (ie at least about 95%) and most preferably entirely polystyrene. The present invention relates to a process for preparing a foamed product related to the step of forming a foamable mixture of polymer (1) having an average molecular weight of about 30,000 to about 500,000. In one embodiment, the polystyrene has an average molecular weight of about 250,000 and is a nucleating agent, foaming nano graphite (2), at least one blowing agent (3), a mixture of an atmospheric region or a reduced pressure region to foam the foamed product, fire protection Other treatment additives 4 such as chemicals and the like.

Nanographite used in the present invention is nanographite having at least one dimension that may be a particle thickness of less than about 100 nanometers by X-ray diffraction. The foam comprises nanosheets of exfoliated graphite dispersed in a polymeric matrix. Peeled graphite is preferably graphite that is inserted and expanded by an oxidation process in which atoms or molecules are inserted in the interplanar space between the planes of the layer of carbon. The inserted graphite is expanded or exfoliated, preferably by brief exposure to high temperatures, to expand the thickness of the graphite. The expanded or exfoliated graphite is mixed with the monomer and polymerized in situ to form a polymer having a network of nanosheets of the exfoliated graphite dispersed therein.

The exfoliated graphite advantageously retains its nanostructure during the polymerization process. The expanded or exfoliated graphite is compressed together into a flexible thin sheet. Nano graphite in foams typically comprise a plurality of nanosheets in layers. Nanosheets range from about 10 to several hundred nanometers, most often from about 10 to about 100 nanometers thick. Details of graphite exfoliation can be found in Graphite Intercalation Compounds I: Structure and Dynamics, H. Zabel; S.A. Solin (1990) and Carbon and Graphite Handbook, C.L. Mantell (1968).

Standard extrusion processes and methods that can be used in the process for making the present invention are described in shared US Pat. No. 5,753,161, which is incorporated herein by reference in its entirety. Details of foaming methods, including expansion and extrusion, can be found in the Plastics Processing Data Handbook (2nd Edition), Rosato, Dominick © 1997 Springer-Verlag.

In the extrusion process, the extruded polystyrene polymer, ie nano graphite foam, is prepared by a twin screw extruder (low shear force) having a flat die and plate shaper. Alternatively, a single screw tandem extruder (high shear force) with a radial die and a denser shaper can be used. Nano graphite is preferably added to the extruder from 0% to about 10% by weight, more preferably from about 0.5 to about 3% by weight, based on the weight of the polymer, depending on the polystyrene, blowing agent, and optionally other additives. In a preferred embodiment, the extruded polystyrene polymer foam is prepared by a twin screw extruder (low shear force) with a flat die and plate shaper. Alternatively, a single screw tandem extruder (high shear force) with a radial die and a denser shaper can be used. Preferably, the nano graphite compound is added to the extruder via multiple feeders depending on the polystyrene, blowing agent, and / or other additives.

The plastic resin mixture, polymer, and optionally other additives containing nano graphite are heated to the melt mixing temperature and mixed thoroughly. The melt mixing temperature should be sufficient to plasticize or melt the polymer. Thus, the melt mixing temperature is above the glass transition temperature or the melting point of the polymer. Preferably, in a preferred embodiment, the melt mixing temperature is about 200 to about 250 ° C, most preferably about 220 to about 240 ° C, depending on the amount of nanographite.

Blowing agents are included to form a foamable gel. The foamable gel is then cooled to the die melting temperature. The die melting temperature is typically lower than the melt mixing temperature, in preferred embodiments about 100 ° C. to about 130 ° C., and most preferably about 120 ° C. The die pressure should be sufficient to prevent prefoaming of the foamable gel containing the blowing agent. Pre-foaming involves unwanted premature foaming of the foamable gel before being extruded into the reduced pressure region. Thus, the die pressure varies with the identity and amount of blowing agent of the foamable gel. Preferably, in a preferred embodiment, the pressure is about 50 to about 80 bar, most preferably about 60 bar. The expansion rate, which is the foam thickness / die gap, is in the range of about 20 to about 70, typically about 60. FIG. 2 shows the viscosity (η ^* [Pa-sec) between 1600 grade polystyrene from NOVA Chemical, PA and the same polystyrene with 1 wt% nano graphite additive in the general die shear rate range (about 100 rad / sec frequency) ]) Is compared. In the normal die temperature operating range of 115 to 125 ° C., the viscosity of polystyrene with nano graphite is higher, but can be handled within the operating temperature period.

Any suitable blowing agent and combination of blowing agents can be used in practice in the present invention. Blowing agents that are actually useful in the present invention include inorganic blowing agents, organic blowing agents and chemical blowing agents. Suitable inorganic blowing agents include carbon dioxide, nitrogen, argon, water, air, nitrogen and helium. Organic blowing agents include aliphatic hydrocarbons having 1 to 9 carbon atoms, aliphatic alcohols having 1 to 3 carbon atoms, and fully and partially halogenated aliphatic hydrocarbons having 1 to 4 carbon atoms. Aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, and neopentane. Aliphatic alcohols include methanol, ethanol, n-propanol, and isopropanol. Fully and partially halogenated aliphatic hydrocarbons include fluorocarbons, chlorocarbons, chlorofluorocarbons and cyclopentane. Examples of fluorocarbons are methyl fluoride, perfluoromethane, ethyl fluoride (HFC-161), ethyl fluoride, 1,1-difluoroethane (HFC-152a), 1,1,1-trifluoro Ethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), pentafluoroethane (HFC- 125), difluoromethane (HFC-32), perfluoroethane, 2,2-difluoropropane (HFC-272fb), 1,1,1-trifluoropropane (HFC-263fb), perfluoro Lopropan, 1,1,1,3,3-pentafluorobutane (HFC-365mfc), 1,1,1,3,3-pentafluoropropane (HFC 245fa), 1,1,1,2, 3,3,3-heptafluoropropane (HFC-227ea), dichloropropane, difluoropropane, perfluorobutane, and perfluorocyclobutane. Partially halogenated chlorocarbons and chlorofluorocarbons used in the present invention are methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane (HCFC- 141b), 1-chloro-1,1-difluoroethane (HCFC-142b), 1,2-difluoroethane (HFC-142), chlorodifluoromethane (HCFC-22), 1,1- Dichloro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124) and the like. Fully halogenated chlorofluorocarbons include trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), trichlorotrifluoroethane (CFC-113), 1,1,1-trifluoro Roethane, pentafluoroethane, dichlorotetrafluoroethane (CFC-114), chloroheptafluoropropane, and dichlorohexafluoropropane. Chemical blowing agents azodicarbonamide, azodiisobutyroni-nitrile, benzenesulfonhydrazide, 4,4-oxybenzene sulfonyl-semicarbazide, p- Toluene sulfonyl semi-carbazide, barium azodicarboxylate, and N, N'-dimethyl-N, N'-dinitrosoterephthalamide, and trihydrazino triazine.

Mixtures of blowing agents such as mixtures comprising 1,1,2,2-tetrafluoroethane (HFC-134a) in approximately the same amount as 1,1-difluoroethane (HFC-152a) can be used in the present invention. have. About 50% of 134a blowing agent and about 50% of 152b blowing agent. Both components are based on the weight of the polymer. However, for low density, thick products, the amount of 152a can be increased up to about 60% or more based on the polymer weight.

Preference is given here to using from about 6 to about 14% by weight, preferably about 11% by weight of cyclopentane, based on the weight of the polymer. It is preferred to add about 0 to about 4% of ethanol, about 3 to about 6%, preferably about 3.5% of carbon dioxide. All percentages are based on the weight of the polymer.

Optional additives may be included in the extruded foam product and include additional infrared attenuators, plasticizers, fire protection chemicals, pigments, elastomers, extrusion aids, antioxidants, fillers, antistatic agents, UV absorbers, citric acid, nucleating agents, surfactants , Processing aids and the like. Such optional additives may be included in any amount to obtain a foamable gel of the desired characteristics or the resulting extruded foamed product. Preferably, optional additives are added to the resin mixture but may be added to the extrusion foam manufacturing process in an alternative manner.

The product produced by the process described above is a rigid foamed insulation board about 1/8 to about 12 inches thick, typically about 1 to about 4 inches thick. The density of the foam board is typically about 1.2 to about 5 pcf, typically about 1.4 to about 3 pcf. The resulting board is silver with a glossy surface.

As mentioned above, the nano graphite in the foam controls the cell morphology. Nano scale graphite acts as a nucleating agent in the foaming process. 3 is an SEM image of a foam comprising 1% nano graphite in a polystyrene foam. The average cell size of the foam without any other nucleating agent, such as talc, is about 220 microns and is oriented in the x / z direction = 1.26 (x 0.254, y 0.205, z 0.201 mm). 4 is an SEM image of the cell walls and struts of the foamed article. The polystyrene foam contains 1% of nano graphite. The cell wall is about 0.86 microns thick and the strut diameter is about 3.7 microns.

5 shows the UV protection capability of the polystyrene foam boards with nano graphite of the present invention when the board is exposed to UV radiation. The test method used is a QUV test by color measurement. Test methods and material standards for QUV testing include ISO 4982-1 Plastics, ASTM G-151, ASTM G-154, ASTM G-53, British Standard BS 2782, Part 5, Method 540B, and SAE J2020, JIS D0205 . All test methods and standards indicated above are referenced herein. Color measurements are made on the L ^* a ^* b scale. L scales from 0 to 100 represent the relationship from white to black. Gray nano graphite foam showed little change even with prolonged UV exposure over 100 days. The a and b scales from 1 to -1 show different color changes from red to green and yellow to blue. Minor changes in color were observed after at least 90 days of UV exposure to the nano graphite foam boards.

As is generally described herein, other understandings may be obtained by reference to any particular embodiment shown below which is provided for illustration only and is not intended to be limiting or exhaustive unless otherwise specified.

Example 1

The present invention is not to be construed as a limitation, and is further illustrated by Example 1 below, in which all foam boards are extruded polystyrene foam boards. In the following samples and sample samples, the rigid polystyrene foam boards are prepared by twin screw LMP extruders with flat dies and shaper plates, and two single screw in-line extruders with radial dies and a denser shaper. Vacuum may also be applied to both the pilot and manufacturing lines described above.

Table 1 shows the process conditions for a sample in a twin screw extruder to make a foam board having a width of 16 inches and a thickness of 1 inch.

The thickness of the nanographite used was found to be 29.7 nm by X-ray diffraction, and 51 nm after compounding with about 60% by weight of polystyrene. Carbon black is not part of the mixture with nano graphite due to its poor process capability and high smoke density during fire testing.

The results of this example are shown in Table 2. All R-values and compressive strengths were tested after 180 days of sample.

As shown in the sample above, the addition of nano graphite in the foaming treatment, preferably from about 1% to about 3% by weight of the solid foam polymer, has a significant effect on the thermal resistance. The R-value ranged from about 5.7 to about 6.0.

Example 2

Table 3 compares the operating conditions between batch foaming and conventional low density foam extrusion.

Prior to batch foaming, the polymerized nano graphite / polystyrene compound is heated and compressed into a solid form. The solid sheet is cut into small pieces according to the size of the pressure vessel, such as 77 x 32 x 1 mm. The solid sheet sample is placed in a mold and foamed at about 80 to about 160 ° C., typically about 120 ° C. and about 500 to about 4000 psi, typically about 2000 psi. The solid sheet is held in a pressurized container for about 8 to about 50 hours, typically about 12 hours, after which the pressure in the container is released quickly (about 12 seconds) for foaming.

The nanographite / polystyrene foam of the sample to be batch foamed is evaluated to determine the amount of infrared radiation delivered through the foam. Infrared light is the main form of thermal radiation.

A piece of batch formed sample containing polystyrene and 3% graphite and two other comparative samples containing polystyrene or polystyrene and 5% nanoclay were selected. On one side of the foam sample was placed the light source of the infrared laser. On the other side of the sample, a detector is placed to record the transmitted light intensity or a temperature camera is placed to watch for surface temperature changes. The results are summarized in Table 4.

* In-situ polymerized compound with montmorylated 2-methacryloyloxyethylhexadialkyldimethyl and ammonium bromide (MHAB) with 5% reactive cationic surfactant Na + and 95% styrene monomer

As shown in Table 4, 10% light transmission occurs through pure PS foam samples, while only 4% light through PS / 5% clay foam samples and only 2% light through PS / 3% graphite samples. The transfer took place. Both clay and graphite have an attenuation effect on infrared light, but as shown in the table above, PS / 3% graphite showed significantly better transmission attenuation.

On the side opposite the light source of the sample, the temperature of PS / graphite rose slightly to about 2-3 ° F after 60 seconds of exposure (Table 5). The surface temperature for foam samples of pure PS (sample sample) and PS with MHABS nanoclay did not change significantly. As such, the PS / graphite foam dampens thermal radiation and enhances thermal solid conduction. In addition, with improved graphite dispersion and concentration, this trend is expected to be more pronounced.

The foregoing descriptions of the embodiments of the present specification apply the knowledge of the relevant technology (including the contents of the references used herein), and thereby, without unreasonable experimentation, the general concept of the present invention for various applications such as these specific embodiments. It will be fully appreciated the general nature of the invention which can be easily changed and / or adapted without departing from the scope of the invention. Accordingly, such adaptations and modifications should be within the meaning and scope equivalent to the described embodiments, based on the description and teachings described herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, and the terms or phrases herein may be interpreted by one of ordinary skill in the art in light of the description and teachings described herein, in combination with the knowledge of those skilled in the art.

The invention of the present application has been described above generically and with respect to specific embodiments. Although the present invention has been described as what is considered to be the preferred embodiments, a wide variety of alternatives known to those skilled in the art can be selected within the comprehensive description. The invention is not otherwise limited except as described in the claims set out below.

Claims (20)

a) a polymer, b) at least one blowing agent, and c) nano graphite Polymeric foam material comprising a. The polymeric foam material of claim 1, wherein the nano graphite is present at greater than 0 wt% to about 10 wt% based on the polymer. The blowing agent of claim 1 wherein the blowing agent is 1,1,2,2-tetrafluoroethane (HFC-134), 1,1-difluoroethane (HFC-152a) and 1,2-difluoroethane ( Polymeric foam material comprising a mixture of HFC-142). The method of claim 1, further comprising at least one additive selected from the group of cell size expanders, infrared attenuators, plasticizers, fire protection chemicals, pigments, elastomers, extrusion aids, antioxidants, fillers, antistatic agents and UV absorbers. A polymeric foam material comprising. The polymeric foam material of claim 1, wherein the nanographite further comprises a plurality of nanosheets. 6. The polymeric foam material of claim 5, wherein the plurality of nanosheets have a thickness of about 10 to several hundred nanometers, mainly about 10 to about 100 nanometers. The polymeric foam material of claim 6, wherein the plurality of nanosheets comprise a plurality of single carbon layers of graphite. No content The polymeric foam material of claim 1, wherein the R-value of the material is from about 3 to about 8. 8. The method of claim 1, wherein the polymer is polyolefin, polyvinyl chloride, polycarbonate, polyetherimide, polyamide, polyester, polyvinylidene chloride, polymethyl methacrylate, polyurethane, polyurea, phenol formaldehyde, poly Polymeric foam materials selected from the group of sociaurates, phenolics, copolymers and terpolymers thereof, thermoplastic polymer mixtures, rubber modified polymers. As a method of producing an extruded polymer foam, a) mixing a resin mixture comprising a polymer and a nano graphite compound, b) heating the resin mixture to a melt mixing temperature, c) incorporating at least one blowing agent in the resin mixture under pressure sufficient to prevent prefoaming of the gel, d) cooling the gel to the die melting temperature, e) extruding the gel through the die into a lower die pressure region to form a foam. The method of claim 11, wherein the nano graphite compound is added in an amount of greater than 0 wt% to about 100 wt% based on the polymer. 13. The blowing agent of claim 12 wherein the blowing agent is 1,1,2,2-tetrafluoroethane (HFC-134), 1,1-difluoroethane (HFC-152a) and 1,2-difluoroethane ( A method for producing an extruded polymer foam, comprising a mixture of HFC-142). 12. The at least one additive of claim 11, wherein the at least one additive is selected from the group consisting of cell size expanders, infrared attenuators, plasticizers, fire protection chemicals, pigments, elastomers, extrusion aids, antioxidants, fillers, antistatic agents and UV absorbers. Further comprising mixing in the mixture. The method of claim 11, wherein the polymer is polystyrene. As a method of producing a batch polymer foam, a) adding an extruded or molded polymer solid containing nano graphite to a pressure vessel, b) adding at least one blowing agent to the pressure vessel, c) pressurizing the pressure vessel to a level sufficient to force an appropriate amount of blowing agent into the free volume of the polymer, d) reducing the pressure when the blowing agent completely saturates the polymer and removing a roll of polymer containing nanographite from the pressure vessel. a) a polymer, b) at least one blowing agent, and c) nanographite Rigid foam insulation board comprising a. 18. The rigid foam insulation board of claim 17, wherein the R-value of the board is about 3 to about 8. 18. The rigid foam insulation board of claim 17, wherein the insulation board has a thickness of about 1/8 inch to about 10 inches. 20. The rigid foam insulation board of claim 19, wherein the nano graphite is present at greater than 0 weight percent to about 10 weight percent based on polymer.

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