CA1283498C - Low density porous elastic cross-linked polymeric materials and theirpreparation - Google Patents
Low density porous elastic cross-linked polymeric materials and theirpreparationInfo
- Publication number
- CA1283498C CA1283498C CA000532656A CA532656A CA1283498C CA 1283498 C CA1283498 C CA 1283498C CA 000532656 A CA000532656 A CA 000532656A CA 532656 A CA532656 A CA 532656A CA 1283498 C CA1283498 C CA 1283498C
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- Prior art keywords
- elastic
- polymer
- porous polymer
- range
- emulsion
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/12—Polymerisation in non-solvents
- C08F2/16—Aqueous medium
- C08F2/22—Emulsion polymerisation
- C08F2/24—Emulsion polymerisation with the aid of emulsifying agents
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/28—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
- C08J9/283—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum a discontinuous liquid phase emulsified in a continuous macromolecular phase
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Polymerisation Methods In General (AREA)
- Other Resins Obtained By Reactions Not Involving Carbon-To-Carbon Unsaturated Bonds (AREA)
- Graft Or Block Polymers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Low density porous elastic cross-linked polymeric materials and their preparation.
This invention discloses a novel elastic cross-linked porous polymer having a porosity in the range 75 to 98%
internal phase volume and having interconnected pores, said pores having a mean pore diameter in the range 15µm to 80µm, said polymer having an elastic return from 50%
compression to 90% of initial thickness of less than 120 seconds, and a process for its production.
Low density porous elastic cross-linked polymeric materials and their preparation.
This invention discloses a novel elastic cross-linked porous polymer having a porosity in the range 75 to 98%
internal phase volume and having interconnected pores, said pores having a mean pore diameter in the range 15µm to 80µm, said polymer having an elastic return from 50%
compression to 90% of initial thickness of less than 120 seconds, and a process for its production.
Description
- 1 - T.3026 LOW DENSITY POROUS ELASTIC CROSS-LINKED POLYMERIC
MATERIALS AND THEIR PREPARATION
This invention relates to low density polymeric materials, more particularly to low density porous elastic cross-linked polymeric materials and methods for their preparation. The porous materials comprise pores interconnected by holes in their side walls so forming a permeable structure.
Prior Art In United States Patent Specification No 4 522 953 there have been disclosed novel polymeric materials prepared from high internal phase emulsions and these materials have outstanding porosity with respect to hydrophobic li~uids such as oils. These known materials are prepared by polymerising water-in-oil high internal phase emulsions co~prising various vinyl monomers and using certain selected surfactants.
Other specifications referred to in the above-mentioned United States patent have disclosed the preparation of porous polymeric beads and, also, the use 34~8 - 2 - T.3026 of various pre-formed polymers together with monomers to prepare water-filled porous objects.
The Present Invention It has now been found that by careful selection of monomers and by control of processing conditions low density porous cross-linked polymeric materials having a useful degree of elasticity can be obtained.
Accordingly, the present invention provides an elastic cross-linked porous polymer having a porosity in the range 75 to 98% and having interconnected pores, said pores having a mean pore diameter in the range 15 to 80~m, said polymer having an elastic return from 50~ compression to 90% of original thickness of less than 120 seconds.
Preferably the elastic porous polymer has an elastic return from 50% compression to 90~ of initial thickness of less than 40 seconds.
Any elastic material will have a glass transition temperature below ambient temperature i.e. its surrounding temperature. Thus the present porous polymers should have a glass transition temperature (Tg) below ambient temperature, which is usually room temperature, but can be above or below room temperature depending on the conditions of the intended use of the polymer.
In a preferred form of this invention, the polymer comprises up to 50~ by weight of styrene and at least S0 by weight of an alkyl acrylate or methacrylate. In a further preferred form of the invention, the alkyl acrylate comprises 2-ethyl hexyl acrylate, n-butyl acrylate or a mixture thereof.
1~34'~8 - 3 - T.3026 A surprising feature of the present invention is that the desired elastic properties of the porous polymer are only achieved when the mean pore diameter is in the specified range. It has been found that additional or excessive mixing of the emulsion, which reduces both the breadth and mean value of the distribution of pore diameters, produces a material which collapses irreversibly on drying. Preferably the elastic cross-linked polymer has pores having a mean pore diameter in the range 25~m to 80~m.
Accordingly, in a further aspect of the present invention there is provided a process for the preparation of an elastic porous polymer in which the monomers, at least one of which is polyfunctional, and an oil-soluble surfactant are mixed together and an aqueous phase is added in sufficient quantity to generate a high internal phase volume emulsion in the range 75 to 98% internal phase volume, the emulsion being given further sufficient stirring to generate droplets having a mean droplet diameter in the range 15 to 80~m, said emulsion in the presence of a polymerisation initiator then beinq subjected to heating to polymerise the monomers.
Suitably a water-soluble polymerisation initiator is employed and is added to the monomer mixture in the aqueous phase. Alternatively, however, or as well as an oil-soluble polymerisation initiator can be employed, suitably being admixed with the monomer mixture prior to addition of the aqueous phase.
The porous polymer produced by the above process will have the desired structure for the production of an elastic porous polymer. However, the porous polymer will contain residual surfactant and for some applications this should be removed. Accordingly, in a further preferred 1~34~3 - 4 - T.3026 form of the present invention, the polymer is washed substantially free of surfactant and dried to produce the novel elastic cross-linked porous polymer provided according to the present invention.
The oil-soluble surfactant to be used in the preparation of the high internal phase emulsion preferably has an HLB value in the range of about 2 to about 6 and a A preferred s~urfactant is sorbitan monooleate sold under the trade name~Span 80.
To determine the distribution of pore sizes and the mean pore diameter of the porous polymer an image analysis technique was used to compile a histogram representing the distribution of void sizes in the sample. The image analysis was carried out on a fracture surface of the dried porous elastic polymer. The mean void diameter d was then calculated as the number-average d = nidi ~ni where ni is the number of voids of diameter di in bin i of the histogram.
The term "elastic return" employed in the present specification ard claims is defined by the following experiment.
Dry samples of the washed porous polymeric material, in the form of cylinders 5.5cm in diameter and 2cm thick were compressed to appro~imately 50~ of their initial thickness using an Instron Tensometer (model 4202) at a strain rate of '.5mm min 1. The samples were kept in a compressed state for 30 seconds and the load was then released. The time 'or recovery from 50% to 90~ of the initial sample thickness was determined using a high speed video camera and a qraduated scale mounted behind the sample.
1~834~
MATERIALS AND THEIR PREPARATION
This invention relates to low density polymeric materials, more particularly to low density porous elastic cross-linked polymeric materials and methods for their preparation. The porous materials comprise pores interconnected by holes in their side walls so forming a permeable structure.
Prior Art In United States Patent Specification No 4 522 953 there have been disclosed novel polymeric materials prepared from high internal phase emulsions and these materials have outstanding porosity with respect to hydrophobic li~uids such as oils. These known materials are prepared by polymerising water-in-oil high internal phase emulsions co~prising various vinyl monomers and using certain selected surfactants.
Other specifications referred to in the above-mentioned United States patent have disclosed the preparation of porous polymeric beads and, also, the use 34~8 - 2 - T.3026 of various pre-formed polymers together with monomers to prepare water-filled porous objects.
The Present Invention It has now been found that by careful selection of monomers and by control of processing conditions low density porous cross-linked polymeric materials having a useful degree of elasticity can be obtained.
Accordingly, the present invention provides an elastic cross-linked porous polymer having a porosity in the range 75 to 98% and having interconnected pores, said pores having a mean pore diameter in the range 15 to 80~m, said polymer having an elastic return from 50~ compression to 90% of original thickness of less than 120 seconds.
Preferably the elastic porous polymer has an elastic return from 50% compression to 90~ of initial thickness of less than 40 seconds.
Any elastic material will have a glass transition temperature below ambient temperature i.e. its surrounding temperature. Thus the present porous polymers should have a glass transition temperature (Tg) below ambient temperature, which is usually room temperature, but can be above or below room temperature depending on the conditions of the intended use of the polymer.
In a preferred form of this invention, the polymer comprises up to 50~ by weight of styrene and at least S0 by weight of an alkyl acrylate or methacrylate. In a further preferred form of the invention, the alkyl acrylate comprises 2-ethyl hexyl acrylate, n-butyl acrylate or a mixture thereof.
1~34'~8 - 3 - T.3026 A surprising feature of the present invention is that the desired elastic properties of the porous polymer are only achieved when the mean pore diameter is in the specified range. It has been found that additional or excessive mixing of the emulsion, which reduces both the breadth and mean value of the distribution of pore diameters, produces a material which collapses irreversibly on drying. Preferably the elastic cross-linked polymer has pores having a mean pore diameter in the range 25~m to 80~m.
Accordingly, in a further aspect of the present invention there is provided a process for the preparation of an elastic porous polymer in which the monomers, at least one of which is polyfunctional, and an oil-soluble surfactant are mixed together and an aqueous phase is added in sufficient quantity to generate a high internal phase volume emulsion in the range 75 to 98% internal phase volume, the emulsion being given further sufficient stirring to generate droplets having a mean droplet diameter in the range 15 to 80~m, said emulsion in the presence of a polymerisation initiator then beinq subjected to heating to polymerise the monomers.
Suitably a water-soluble polymerisation initiator is employed and is added to the monomer mixture in the aqueous phase. Alternatively, however, or as well as an oil-soluble polymerisation initiator can be employed, suitably being admixed with the monomer mixture prior to addition of the aqueous phase.
The porous polymer produced by the above process will have the desired structure for the production of an elastic porous polymer. However, the porous polymer will contain residual surfactant and for some applications this should be removed. Accordingly, in a further preferred 1~34~3 - 4 - T.3026 form of the present invention, the polymer is washed substantially free of surfactant and dried to produce the novel elastic cross-linked porous polymer provided according to the present invention.
The oil-soluble surfactant to be used in the preparation of the high internal phase emulsion preferably has an HLB value in the range of about 2 to about 6 and a A preferred s~urfactant is sorbitan monooleate sold under the trade name~Span 80.
To determine the distribution of pore sizes and the mean pore diameter of the porous polymer an image analysis technique was used to compile a histogram representing the distribution of void sizes in the sample. The image analysis was carried out on a fracture surface of the dried porous elastic polymer. The mean void diameter d was then calculated as the number-average d = nidi ~ni where ni is the number of voids of diameter di in bin i of the histogram.
The term "elastic return" employed in the present specification ard claims is defined by the following experiment.
Dry samples of the washed porous polymeric material, in the form of cylinders 5.5cm in diameter and 2cm thick were compressed to appro~imately 50~ of their initial thickness using an Instron Tensometer (model 4202) at a strain rate of '.5mm min 1. The samples were kept in a compressed state for 30 seconds and the load was then released. The time 'or recovery from 50% to 90~ of the initial sample thickness was determined using a high speed video camera and a qraduated scale mounted behind the sample.
1~834~
- 5 _ T.3026 The polymer may be a cross-linked homopolymer or a copolymer with a Tg below ambient and the preferred monomers for use according to the present invention include styrene, 2-ethyl hexyl acrylate, n-butyl and isobutyl acrylate, hexyl acrylate, lauryl methacrylate and isodecyl methacrylate and mixtures thereof. Other monomers can also be used providing the glass transition temperature (Tg) of the final polymer is below ambient temperature.
Suitable cross-linking agents for use in this invention include divinyl benzene, diethylene glycol dimethacrylate and 3-butylene dimethacrylate.
The preferred degree of cross-linking ranges from 2 to about 20% and is preferably about 5%.
A factor concerned with stability of the emulsion is the presence in the aqueous phase of a water-soluble salt.
Suitable salts include soluble sodium, calcium and aluminium salts. The amount present depends on the monomer and surfactant combination and is related to the valences of the metal component of the salt and it is preferred to use a polyvalent salt.
The followir.g examples illustrate the preparation of the porous elastic polymeric materials provided by this invention.
Example l 2 g of SPAN ao were dissolved in a mixture of 6ml of 2-ethyl hexyl acrylate, 4ml of styrene and lml of commercial divinyl benzene (DVB) containing _O.Sml of ethyl vinyl benzene. The aqueous phase ~lOOml of water containing 2.5gl 1 of potassium persulphate and 0.1 moles - 6 - T.3026 1 1 O~ calcium chloride) was dispersed in the monomer mixture using a three bladed paddle stirrer in a polypropylene beaker. Once all the aqueous phase was added the high internal phase emulsion was stirred for a further 120 seconds and then poured into a polypropylene bottle and sealed. The emulsion was then left to polymerise at 60C for approximately 8 hours.
The sample was removed from its container and squeezed to remove the aqueous phase~ The porous polymer was then washed in water and isopropanol by repeatedly squeezing and re-expar.ding the sample. Finally the sample was squeezed to remove the last isopropanol wash liquor and allowed to dry in air.
A sample of the dried, cleaned surfactant-free polymer was subjected to the elastic return test as described above.
Further porous polymer samples were made using the procedure outlined above with different styrene/ethyl hexyl acrylate compositions and the results are set out below in Table I.
~able I
Startinq comPosition Time to Return from (StYrene: EHA) ;0~ to 90~ Initial Mean Pore Tq + 10~ DVB Thickness (seconds) Diameter (~m) (C) 50 : 50 oo 60 32 40 : 60 30 55 26 30 : 70 20 62 -ll 20 : 80 9 64 -20 1~34~8 - 7 - T.3026 Mixing time for example - 2 minutes.
From the above table it will be appreciated that the content of ethyl hexyl acrylate in the total composition has a significant effect upon the elastic return time.
Each of the above samples had an internal phase volume of 90% .
Example 2 2g of SPAN 80 were dissolved in a mixture of 7ml of n-butyl acrylate, 3ml of styrene and lml of commercial divinyl benzene (DVB) containing ~0.5ml of ethyl vinyl benzene. 100ml of an aqueous phase containing 2.5gl 1 of potassium persulphate and 0.1 moles 1 1 of calcium chloride were dispersed in the monomer mixture using a three bladed paddle stirrer in a polypropylene beaker.
Once all the aqueous phase was added the high internal phase emulsion was stirred for a further 120 seconds and then poured into a polypropylene mould and sealed. The emulsion was then left to polymerise at 60C for approximately 8 hours. The sample was then washed and dried as set out in Example 1.
The present procedure was repeated employing 2g of Span 80, 8ml of n-butyl acrylate, 2ml of styrene, lml of DVB and 100ml of the aqueous phase containing 2.5gl 1 potassium persulphate and 0.1 moles 1 calcium chloride.
Each of the resulting washed and dried polymers was subjected to the elastic return test described above. The results are given in Table II.
4~
Suitable cross-linking agents for use in this invention include divinyl benzene, diethylene glycol dimethacrylate and 3-butylene dimethacrylate.
The preferred degree of cross-linking ranges from 2 to about 20% and is preferably about 5%.
A factor concerned with stability of the emulsion is the presence in the aqueous phase of a water-soluble salt.
Suitable salts include soluble sodium, calcium and aluminium salts. The amount present depends on the monomer and surfactant combination and is related to the valences of the metal component of the salt and it is preferred to use a polyvalent salt.
The followir.g examples illustrate the preparation of the porous elastic polymeric materials provided by this invention.
Example l 2 g of SPAN ao were dissolved in a mixture of 6ml of 2-ethyl hexyl acrylate, 4ml of styrene and lml of commercial divinyl benzene (DVB) containing _O.Sml of ethyl vinyl benzene. The aqueous phase ~lOOml of water containing 2.5gl 1 of potassium persulphate and 0.1 moles - 6 - T.3026 1 1 O~ calcium chloride) was dispersed in the monomer mixture using a three bladed paddle stirrer in a polypropylene beaker. Once all the aqueous phase was added the high internal phase emulsion was stirred for a further 120 seconds and then poured into a polypropylene bottle and sealed. The emulsion was then left to polymerise at 60C for approximately 8 hours.
The sample was removed from its container and squeezed to remove the aqueous phase~ The porous polymer was then washed in water and isopropanol by repeatedly squeezing and re-expar.ding the sample. Finally the sample was squeezed to remove the last isopropanol wash liquor and allowed to dry in air.
A sample of the dried, cleaned surfactant-free polymer was subjected to the elastic return test as described above.
Further porous polymer samples were made using the procedure outlined above with different styrene/ethyl hexyl acrylate compositions and the results are set out below in Table I.
~able I
Startinq comPosition Time to Return from (StYrene: EHA) ;0~ to 90~ Initial Mean Pore Tq + 10~ DVB Thickness (seconds) Diameter (~m) (C) 50 : 50 oo 60 32 40 : 60 30 55 26 30 : 70 20 62 -ll 20 : 80 9 64 -20 1~34~8 - 7 - T.3026 Mixing time for example - 2 minutes.
From the above table it will be appreciated that the content of ethyl hexyl acrylate in the total composition has a significant effect upon the elastic return time.
Each of the above samples had an internal phase volume of 90% .
Example 2 2g of SPAN 80 were dissolved in a mixture of 7ml of n-butyl acrylate, 3ml of styrene and lml of commercial divinyl benzene (DVB) containing ~0.5ml of ethyl vinyl benzene. 100ml of an aqueous phase containing 2.5gl 1 of potassium persulphate and 0.1 moles 1 1 of calcium chloride were dispersed in the monomer mixture using a three bladed paddle stirrer in a polypropylene beaker.
Once all the aqueous phase was added the high internal phase emulsion was stirred for a further 120 seconds and then poured into a polypropylene mould and sealed. The emulsion was then left to polymerise at 60C for approximately 8 hours. The sample was then washed and dried as set out in Example 1.
The present procedure was repeated employing 2g of Span 80, 8ml of n-butyl acrylate, 2ml of styrene, lml of DVB and 100ml of the aqueous phase containing 2.5gl 1 potassium persulphate and 0.1 moles 1 calcium chloride.
Each of the resulting washed and dried polymers was subjected to the elastic return test described above. The results are given in Table II.
4~
- 8 - T.3026 Table II
Startin~
5Composition Time to return from Mean Pore (stYrene: n-butYl50% to 90~ Initial Diameter acrvlate) Thickness (seco ds) (~m) 40:60 00 34 10 30:70 90 32.5 20:80 40 35 10:90 6 32.5 As in Example 1 the sample with the greater amount of acrylate had the shorter elastic return time. Each of the above samples had an internal phase of approximately 91~.
The sample having an infinite time to return from 50~ to 90~ initial thickness had a glass transition temperature (Tg) above ambient temperature whilst those samples embodying the present invention had a glass transition temperature (Tg) below ambient temperature, which in the present case was a room temperature of 23C.
Startin~
5Composition Time to return from Mean Pore (stYrene: n-butYl50% to 90~ Initial Diameter acrvlate) Thickness (seco ds) (~m) 40:60 00 34 10 30:70 90 32.5 20:80 40 35 10:90 6 32.5 As in Example 1 the sample with the greater amount of acrylate had the shorter elastic return time. Each of the above samples had an internal phase of approximately 91~.
The sample having an infinite time to return from 50~ to 90~ initial thickness had a glass transition temperature (Tg) above ambient temperature whilst those samples embodying the present invention had a glass transition temperature (Tg) below ambient temperature, which in the present case was a room temperature of 23C.
Claims (10)
1. An elastic cross-linked porous polymer having a porosity in the range 75 to 98% internal phase volume and having interconnected pores, said pores having a mean pore diameter in the range 15µm to 80µm, said polymer having an elastic return from 50% compression to 90% of initial thickness of less than 120 seconds.
2. An elastic porous polymer as claimed in claim 1 having an elastic return from 50% compression to 90% of initial thickness of less than 40 seconds.
3. An elastic porous polymer as claimed in claim 1, in which the polymer comprises up to 50% by weight of styrene and at least 50% by weight of an alkyl acrylate or methacrylate or mixture thereof.
4. An elastic porous polymer as claimed in claim 3, in which the alkyl acrylate comprises 2-ethyl-hexyl-acrylate.
5. An elastic porous polymer as claimed in claim 1, 2 or 3, in which the said pores have a mean pore diameter in the range 25µm to 80µm.
6. An elastic porous polymer as claimed in claim 1, 2 or 3, in which the void volume is between 85 and 93%.
7. A process for the preparation of an elastic porous polymer as claimed in any one of the preceding claims, in which the monomers, at least one of which is polyfunctional, and an oil soluble surfactant are mixed together and an aqueous phase is added in a sufficient quantity to generate a high internal phase volume emulsion in the range 75 to 98%
internal phase volume, the emulsion being given sufficient stirring to generate droplets having a mean droplet diameter in the range 15µm to 80µm, said emulsion in the presence of a polymerisation initiator then being subjected to heating to polymerise the monomers.
internal phase volume, the emulsion being given sufficient stirring to generate droplets having a mean droplet diameter in the range 15µm to 80µm, said emulsion in the presence of a polymerisation initiator then being subjected to heating to polymerise the monomers.
8. A process as claimed in claim 7 in which a water-soluble polymerisation initiator is added in the aqueous phase.
9. A process as claimed in claim 7 in which the polymer is washed substantially free of surfactant and dried.
10. A process as claimed in claim 7, 8 or 9 in which a water-soluble salt is added to the aqueous phase to enhance the stability of the emulsion prior to polymerisation.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB868607535A GB8607535D0 (en) | 1986-03-26 | 1986-03-26 | Elastic cross-linked polymeric materials |
| GB8607535 | 1986-03-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1283498C true CA1283498C (en) | 1991-04-23 |
Family
ID=10595282
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000532656A Expired - Lifetime CA1283498C (en) | 1986-03-26 | 1987-03-20 | Low density porous elastic cross-linked polymeric materials and theirpreparation |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US4788225A (en) |
| EP (1) | EP0239360B1 (en) |
| JP (1) | JP2774988B2 (en) |
| AT (1) | ATE113304T1 (en) |
| AU (1) | AU597950B2 (en) |
| CA (1) | CA1283498C (en) |
| DE (1) | DE3750681T2 (en) |
| ES (1) | ES2062979T3 (en) |
| GB (1) | GB8607535D0 (en) |
| ZA (1) | ZA872197B (en) |
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| US5550167A (en) * | 1995-08-30 | 1996-08-27 | The Procter & Gamble Company | Absorbent foams made from high internal phase emulsions useful for acquiring aqueous fluids |
| US6147131A (en) | 1995-11-15 | 2000-11-14 | The Dow Chemical Company | High internal phase emulsions (HIPEs) and foams made therefrom |
| US5977194A (en) * | 1995-11-15 | 1999-11-02 | The Dow Chemical Company | High internal phase emusions and porous materials prepared therefrom |
| US5817704A (en) * | 1996-03-08 | 1998-10-06 | The Procter & Gamble Company | Heterogeneous foam materials |
| US6048908A (en) * | 1997-06-27 | 2000-04-11 | Biopore Corporation | Hydrophilic polymeric material |
| US6013589A (en) * | 1998-03-13 | 2000-01-11 | The Procter & Gamble Company | Absorbent materials for distributing aqueous liquids |
| US6083211A (en) * | 1998-03-13 | 2000-07-04 | The Procter & Gamble Company | High suction polymeric foam materials |
| US6160028A (en) * | 1998-07-17 | 2000-12-12 | The Procter & Gamble Company | Flame retardant microporous polymeric foams |
| US6245697B1 (en) | 1998-11-12 | 2001-06-12 | The Procter & Gamble Company | Flexible mat for absorbing liquids comprising polymeric foam materials |
| WO2001027164A1 (en) | 1999-10-12 | 2001-04-19 | Nippon Shokubai Co., Ltd. | Method for production of porous cross-linked polymer |
| US6323250B1 (en) | 1999-11-18 | 2001-11-27 | Nippon Shokubai Co. Ltd | Method for production of porous material |
| US6395793B1 (en) | 1999-11-18 | 2002-05-28 | Nippon Shokubai Co., Ltd. | Method for production of porous material |
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| JP4330265B2 (en) | 2000-10-24 | 2009-09-16 | 株式会社日本触媒 | Method for producing porous crosslinked polymer |
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| US7820729B2 (en) * | 2006-04-13 | 2010-10-26 | University of Newcastle Upon Tyne, c/o School of Chemical Engineering and Advanced Materials | Process for preparing a functionalised polyHIPE polymer |
| US8211310B2 (en) * | 2006-11-20 | 2012-07-03 | Cytosorbents, Inc. | Size-selective polymer system |
| EP2461777A1 (en) * | 2009-08-04 | 2012-06-13 | Hearing Components, Inc. | Foam compositions with enhanced sound attenuation |
| CN104193884B (en) * | 2014-07-23 | 2016-09-28 | 佛山市联塑万嘉新卫材有限公司 | High-intensity water absorbent acrylate foamed materials and its preparation method and application |
| IT201900017309A1 (en) * | 2019-09-26 | 2021-03-26 | P4P S R L | Polymeric materials with a porous and interconnected internal structure based on acrylic monomers obtained through the emulsion technique with a high quantity of internal phase polymerized by UV and related production processes |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US27444A (en) * | 1860-03-13 | Connection | ||
| DE1420831B2 (en) | 1959-07-28 | 1972-04-20 | Will, Günther, Dr , 6100 Darmstadt | METHOD FOR MANUFACTURING POROUS SHAPED BODIES |
| NZ199916A (en) * | 1981-03-11 | 1985-07-12 | Unilever Plc | Low density polymeric block material for use as carrier for included liquids |
| CA1196620A (en) * | 1981-06-26 | 1985-11-12 | Donald Barby | Substrate carrying a porous polymeric material |
| GB2109799B (en) * | 1981-11-20 | 1985-01-23 | Tioxide Group Plc | Production of vesticulated polymer beads |
| ZW17683A1 (en) * | 1982-08-10 | 1985-03-06 | Dulux Australia Ltd | Process of preparing vesiculated polyester granules |
| NZ205449A (en) * | 1982-09-07 | 1986-10-08 | Unilever Plc | Sulphonated,porous,cross-linked polymeric material |
| US4489174A (en) * | 1983-07-26 | 1984-12-18 | The Sherwin-Williams Company | Vesiculated beads |
| GB8405680D0 (en) * | 1984-03-05 | 1984-04-11 | Unilever Plc | Porous polymers |
-
1986
- 1986-03-26 GB GB868607535A patent/GB8607535D0/en active Pending
-
1987
- 1987-03-04 US US07/022,143 patent/US4788225A/en not_active Expired - Lifetime
- 1987-03-20 CA CA000532656A patent/CA1283498C/en not_active Expired - Lifetime
- 1987-03-23 JP JP62068748A patent/JP2774988B2/en not_active Expired - Lifetime
- 1987-03-23 AU AU70523/87A patent/AU597950B2/en not_active Expired
- 1987-03-24 AT AT87302517T patent/ATE113304T1/en not_active IP Right Cessation
- 1987-03-24 ES ES87302517T patent/ES2062979T3/en not_active Expired - Lifetime
- 1987-03-24 EP EP87302517A patent/EP0239360B1/en not_active Expired - Lifetime
- 1987-03-24 DE DE3750681T patent/DE3750681T2/en not_active Expired - Lifetime
- 1987-03-25 ZA ZA872197A patent/ZA872197B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62250002A (en) | 1987-10-30 |
| EP0239360A2 (en) | 1987-09-30 |
| ATE113304T1 (en) | 1994-11-15 |
| US4788225A (en) | 1988-11-29 |
| AU597950B2 (en) | 1990-06-14 |
| ZA872197B (en) | 1988-11-30 |
| EP0239360B1 (en) | 1994-10-26 |
| JP2774988B2 (en) | 1998-07-09 |
| DE3750681D1 (en) | 1994-12-01 |
| GB8607535D0 (en) | 1986-04-30 |
| AU7052387A (en) | 1987-10-01 |
| ES2062979T3 (en) | 1995-01-01 |
| EP0239360A3 (en) | 1989-05-31 |
| DE3750681T2 (en) | 1995-03-16 |
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