AU621428B2 - Porous membranes - Google Patents
Porous membranes Download PDFInfo
- Publication number
- AU621428B2 AU621428B2 AU46227/89A AU4622789A AU621428B2 AU 621428 B2 AU621428 B2 AU 621428B2 AU 46227/89 A AU46227/89 A AU 46227/89A AU 4622789 A AU4622789 A AU 4622789A AU 621428 B2 AU621428 B2 AU 621428B2
- Authority
- AU
- Australia
- Prior art keywords
- oil
- polymer
- fibre
- surfactant
- fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- 239000012528 membrane Substances 0.000 title description 30
- 229920000642 polymer Polymers 0.000 claims description 76
- 239000012530 fluid Substances 0.000 claims description 64
- 239000002904 solvent Substances 0.000 claims description 60
- 239000011148 porous material Substances 0.000 claims description 56
- 239000000835 fiber Substances 0.000 claims description 48
- 238000000034 method Methods 0.000 claims description 42
- 239000004094 surface-active agent Substances 0.000 claims description 36
- 239000011248 coating agent Substances 0.000 claims description 31
- 238000000576 coating method Methods 0.000 claims description 31
- -1 polypropylene Polymers 0.000 claims description 29
- 239000000203 mixture Substances 0.000 claims description 28
- 239000004743 Polypropylene Substances 0.000 claims description 18
- 229920001155 polypropylene Polymers 0.000 claims description 18
- 238000005191 phase separation Methods 0.000 claims description 17
- 239000003963 antioxidant agent Substances 0.000 claims description 16
- 230000003078 antioxidant effect Effects 0.000 claims description 16
- 235000006708 antioxidants Nutrition 0.000 claims description 16
- 238000001125 extrusion Methods 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 16
- 239000003921 oil Substances 0.000 claims description 16
- 235000019198 oils Nutrition 0.000 claims description 16
- 239000012071 phase Substances 0.000 claims description 16
- 239000003549 soybean oil Substances 0.000 claims description 15
- 235000012424 soybean oil Nutrition 0.000 claims description 15
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 13
- 238000001816 cooling Methods 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 9
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims description 9
- 239000002736 nonionic surfactant Substances 0.000 claims description 9
- 239000003093 cationic surfactant Substances 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 230000015572 biosynthetic process Effects 0.000 claims description 7
- 239000011159 matrix material Substances 0.000 claims description 7
- 229920000098 polyolefin Polymers 0.000 claims description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 6
- 239000007791 liquid phase Substances 0.000 claims description 6
- 125000002091 cationic group Chemical group 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 5
- WHHKAGDFPQFXLL-QPLCGJKRSA-N (Z)-tetratriacont-9-en-1-ol Chemical class CCCCCCCCCCCCCCCCCCCCCCCC\C=C/CCCCCCCCO WHHKAGDFPQFXLL-QPLCGJKRSA-N 0.000 claims description 4
- 239000004359 castor oil Substances 0.000 claims description 4
- 235000019438 castor oil Nutrition 0.000 claims description 4
- ZEMPKEQAKRGZGQ-XOQCFJPHSA-N glycerol triricinoleate Natural products CCCCCC[C@@H](O)CC=CCCCCCCCC(=O)OC[C@@H](COC(=O)CCCCCCCC=CC[C@@H](O)CCCCCC)OC(=O)CCCCCCCC=CC[C@H](O)CCCCCC ZEMPKEQAKRGZGQ-XOQCFJPHSA-N 0.000 claims description 4
- BXWNKGSJHAJOGX-UHFFFAOYSA-N hexadecan-1-ol Chemical compound CCCCCCCCCCCCCCCCO BXWNKGSJHAJOGX-UHFFFAOYSA-N 0.000 claims description 4
- 229920006395 saturated elastomer Polymers 0.000 claims description 4
- LZOKDCXRCLWQQY-UHFFFAOYSA-N 2-(2-phenoxyethoxy)undecan-2-ol Chemical compound CCCCCCCCCC(C)(O)OCCOC1=CC=CC=C1 LZOKDCXRCLWQQY-UHFFFAOYSA-N 0.000 claims description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 3
- 235000015164 Iris germanica var. florentina Nutrition 0.000 claims description 3
- 241001031074 Ongokea gore Species 0.000 claims description 3
- 239000005662 Paraffin oil Substances 0.000 claims description 3
- 235000019483 Peanut oil Nutrition 0.000 claims description 3
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 3
- 235000019485 Safflower oil Nutrition 0.000 claims description 3
- 235000021322 Vaccenic acid Nutrition 0.000 claims description 3
- ZOJBYZNEUISWFT-UHFFFAOYSA-N allyl isothiocyanate Chemical compound C=CCN=C=S ZOJBYZNEUISWFT-UHFFFAOYSA-N 0.000 claims description 3
- 239000003240 coconut oil Substances 0.000 claims description 3
- 235000019864 coconut oil Nutrition 0.000 claims description 3
- 239000010635 coffee oil Substances 0.000 claims description 3
- 235000005687 corn oil Nutrition 0.000 claims description 3
- 239000002285 corn oil Substances 0.000 claims description 3
- 235000012343 cottonseed oil Nutrition 0.000 claims description 3
- 239000002385 cottonseed oil Substances 0.000 claims description 3
- 235000014113 dietary fatty acids Nutrition 0.000 claims description 3
- UKMSUNONTOPOIO-UHFFFAOYSA-N docosanoic acid Chemical compound CCCCCCCCCCCCCCCCCCCCCC(O)=O UKMSUNONTOPOIO-UHFFFAOYSA-N 0.000 claims description 3
- 239000000194 fatty acid Substances 0.000 claims description 3
- 229930195729 fatty acid Natural products 0.000 claims description 3
- 150000004665 fatty acids Chemical class 0.000 claims description 3
- 150000002191 fatty alcohols Chemical class 0.000 claims description 3
- 125000005456 glyceride group Chemical group 0.000 claims description 3
- 235000011187 glycerol Nutrition 0.000 claims description 3
- 244000023249 iris florentino Species 0.000 claims description 3
- 229940119170 jojoba wax Drugs 0.000 claims description 3
- 239000002018 neem oil Substances 0.000 claims description 3
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid group Chemical group C(CCCCCCC\C=C/CCCCCCCC)(=O)O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 claims description 3
- 239000004006 olive oil Substances 0.000 claims description 3
- 235000008390 olive oil Nutrition 0.000 claims description 3
- IPCSVZSSVZVIGE-UHFFFAOYSA-N palmitic acid group Chemical group C(CCCCCCCCCCCCCCC)(=O)O IPCSVZSSVZVIGE-UHFFFAOYSA-N 0.000 claims description 3
- 239000000312 peanut oil Substances 0.000 claims description 3
- 239000011591 potassium Substances 0.000 claims description 3
- 229910052700 potassium Inorganic materials 0.000 claims description 3
- 239000003813 safflower oil Substances 0.000 claims description 3
- 235000005713 safflower oil Nutrition 0.000 claims description 3
- 239000011734 sodium Substances 0.000 claims description 3
- 229910052708 sodium Inorganic materials 0.000 claims description 3
- UWHZIFQPPBDJPM-BQYQJAHWSA-N vaccenic acid group Chemical class C(CCCCCCCCC\C=C\CCCCCC)(=O)O UWHZIFQPPBDJPM-BQYQJAHWSA-N 0.000 claims description 3
- ALSTYHKOOCGGFT-KTKRTIGZSA-N (9Z)-octadecen-1-ol Chemical compound CCCCCCCC\C=C/CCCCCCCCO ALSTYHKOOCGGFT-KTKRTIGZSA-N 0.000 claims description 2
- ZORQXIQZAOLNGE-UHFFFAOYSA-N 1,1-difluorocyclohexane Chemical compound FC1(F)CCCCC1 ZORQXIQZAOLNGE-UHFFFAOYSA-N 0.000 claims description 2
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 claims description 2
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 2
- HVUMOYIDDBPOLL-XWVZOOPGSA-N Sorbitan monostearate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O HVUMOYIDDBPOLL-XWVZOOPGSA-N 0.000 claims description 2
- PHYFQTYBJUILEZ-UHFFFAOYSA-N Trioleoylglycerol Natural products CCCCCCCCC=CCCCCCCCC(=O)OCC(OC(=O)CCCCCCCC=CCCCCCCCC)COC(=O)CCCCCCCC=CCCCCCCCC PHYFQTYBJUILEZ-UHFFFAOYSA-N 0.000 claims description 2
- 150000001412 amines Chemical class 0.000 claims description 2
- 229960000541 cetyl alcohol Drugs 0.000 claims description 2
- 229940055577 oleyl alcohol Drugs 0.000 claims description 2
- XMLQWXUVTXCDDL-UHFFFAOYSA-N oleyl alcohol Natural products CCCCCCC=CCCCCCCCCCCO XMLQWXUVTXCDDL-UHFFFAOYSA-N 0.000 claims description 2
- 229920001748 polybutylene Polymers 0.000 claims description 2
- 239000001593 sorbitan monooleate Substances 0.000 claims description 2
- 235000011069 sorbitan monooleate Nutrition 0.000 claims description 2
- 229940035049 sorbitan monooleate Drugs 0.000 claims description 2
- 239000001587 sorbitan monostearate Substances 0.000 claims description 2
- 235000011076 sorbitan monostearate Nutrition 0.000 claims description 2
- 229940035048 sorbitan monostearate Drugs 0.000 claims description 2
- 239000003784 tall oil Substances 0.000 claims description 2
- PHYFQTYBJUILEZ-IUPFWZBJSA-N triolein Chemical compound CCCCCCCC\C=C/CCCCCCCC(=O)OCC(OC(=O)CCCCCCC\C=C/CCCCCCCC)COC(=O)CCCCCCC\C=C/CCCCCCCC PHYFQTYBJUILEZ-IUPFWZBJSA-N 0.000 claims description 2
- 229940117972 triolein Drugs 0.000 claims description 2
- 239000012809 cooling fluid Substances 0.000 claims 7
- DUXYWXYOBMKGIN-UHFFFAOYSA-N trimyristoyl-sn-glycerol Natural products CCCCCCCCCCCCCC(=O)OCC(OC(=O)CCCCCCCCCCCCC)COC(=O)CCCCCCCCCCCCC DUXYWXYOBMKGIN-UHFFFAOYSA-N 0.000 claims 3
- 235000019484 Rapeseed oil Nutrition 0.000 claims 2
- 159000000007 calcium salts Chemical class 0.000 claims 2
- 229940113164 trimyristin Drugs 0.000 claims 2
- 229910001873 dinitrogen Inorganic materials 0.000 claims 1
- 125000003976 glyceryl group Chemical group [H]C([*])([H])C(O[H])([H])C(O[H])([H])[H] 0.000 claims 1
- 125000004079 stearyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 claims 1
- 238000010791 quenching Methods 0.000 description 40
- 239000007788 liquid Substances 0.000 description 16
- VSAWBBYYMBQKIK-UHFFFAOYSA-N 4-[[3,5-bis[(3,5-ditert-butyl-4-hydroxyphenyl)methyl]-2,4,6-trimethylphenyl]methyl]-2,6-ditert-butylphenol Chemical group CC1=C(CC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)C(C)=C(CC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)C(C)=C1CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 VSAWBBYYMBQKIK-UHFFFAOYSA-N 0.000 description 13
- 230000035699 permeability Effects 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 239000007787 solid Substances 0.000 description 7
- 235000019441 ethanol Nutrition 0.000 description 6
- 238000001556 precipitation Methods 0.000 description 6
- 238000001330 spinodal decomposition reaction Methods 0.000 description 6
- 229920001169 thermoplastic Polymers 0.000 description 6
- 239000004698 Polyethylene Substances 0.000 description 4
- 239000003945 anionic surfactant Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 150000002334 glycols Chemical class 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 229920000573 polyethylene Polymers 0.000 description 4
- 230000000171 quenching effect Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000008240 homogeneous mixture Substances 0.000 description 3
- 125000006353 oxyethylene group Chemical group 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 238000010583 slow cooling Methods 0.000 description 3
- MGYUQZIGNZFZJS-KTKRTIGZSA-N 2-[2-[(z)-octadec-9-enoxy]ethoxy]ethanol Chemical compound CCCCCCCC\C=C/CCCCCCCCOCCOCCO MGYUQZIGNZFZJS-KTKRTIGZSA-N 0.000 description 2
- MQIUGAXCHLFZKX-UHFFFAOYSA-N Di-n-octyl phthalate Natural products CCCCCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCCCC MQIUGAXCHLFZKX-UHFFFAOYSA-N 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- GLDOVTGHNKAZLK-UHFFFAOYSA-N octadecan-1-ol Chemical compound CCCCCCCCCCCCCCCCCCO GLDOVTGHNKAZLK-UHFFFAOYSA-N 0.000 description 2
- 238000010587 phase diagram Methods 0.000 description 2
- 229930195735 unsaturated hydrocarbon Natural products 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 239000006184 cosolvent Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- RIZMRRKBZQXFOY-UHFFFAOYSA-N ethion Chemical compound CCOP(=S)(OCC)SCSP(=S)(OCC)OCC RIZMRRKBZQXFOY-UHFFFAOYSA-N 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000008570 general process Effects 0.000 description 1
- 239000011874 heated mixture Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000000693 micelle Substances 0.000 description 1
- 238000001471 micro-filtration Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- GOQYKNQRPGWPLP-UHFFFAOYSA-N n-heptadecyl alcohol Natural products CCCCCCCCCCCCCCCCCO GOQYKNQRPGWPLP-UHFFFAOYSA-N 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid Chemical class OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 235000015112 vegetable and seed oil Nutrition 0.000 description 1
- 239000008158 vegetable oil Substances 0.000 description 1
- 238000011041 water permeability test Methods 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/24—Formation of filaments, threads, or the like with a hollow structure; Spinnerette packs therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
- B01D69/085—Details relating to the spinneret
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
- B01D2325/022—Asymmetric membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
- B01D2325/0283—Pore size
-
- 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
- C08J2201/00—Foams characterised by the foaming process
- C08J2201/04—Foams characterised by the foaming process characterised by the elimination of a liquid or solid component, e.g. precipitation, leaching out, evaporation
- C08J2201/052—Inducing phase separation by thermal treatment, e.g. cooling a solution
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mechanical Engineering (AREA)
- Textile Engineering (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Description
i i: 1/ -ic: OPI DATE 28/05/90 AOJP DATE 05/07/90 APPLN. ID 46227 89 PCT NUMBER PCT/AU89/00481
PCI
INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4: (11) International Publication Number: WO 90/05007 B01D 13/04, C08J 9/28 Al (43) Internation alian Ile: a 90 (17.05.90) (21) International Application Number: PCT/AU89/00481 (81) Designated States: A (European nt), BE (European patent), BR, CH (European patent), DE (European (22) International Filing Date: 10 November 1989 (10.11.89) patent), DK, FR (European patent), GB (European patent), IT (European patent), JP, LU (European patent), NL (European patent), NO, SE (European patent), US.
Priority data: PJ 1395 10 November 1988 (10.11.88) AU Published With international search report.
(71) Applicant (for all designated States except US): MEMTEC LIMITED [AU/AU]; One Memtec Parkway, South Windsor, NSW 2756 (AU).
(72) Inventors; and Inventors/Applicants (for US only) FORD, Douglas, Lyons [AU/AU]; 64 Fingal Avenue, Glenhaven, NSW (AU).
KOPP, Clinton, Virgil [US/AU]; 53 Tuckwell Road, Castle Hill, NSW 2154 STREETON, Robert, John, William [AU/AU]; 33 Drummond Street, Windsor, NSW 2756 (AU).
(74) Agent: MAXWELL, Peter, Francis; Peter Maxwell Associates, Blaxland House, 5 Ross Street, Parramatta, NSW 2150 (AU).
(54)Title: POROUS MEMBRANES (57) Abstract A method of making a porous po- ONE PHASE REGION lymeric material by heating a mixture of a thermoplastic polymer and a cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of 4.0 to to a temperature and for a time sufficient for the polymer and surfactant to mutually dissolve. The mixture is then cooled to a temperature so that non-eq- (O uilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the polymer and surfactant so that the polymer and surfactant form two intermingled separate phases of /QU/ QU large interfacial surface area. The sur-
'REGION
factant is then removed from the polym- i er. The porous polymeric material produced by the above method has a lacey or filamentous structure consisting of a plurality of polymer strands connected SOLI/D L/Q/U/D RFGIOA/ together at spaced apart locations along each strand.
0 r
V
~F
S
-1- POROUS MEMBRANES FIELD OF INVENTION This invention relates to porous polyolefin structures and to a process for the manufacture of such porous structures.
BACKGROUND ART Porous polymeric structures having pores in the range of 0.01 to 10 microns are commonly used for microfiltration.
Such membrane structures may be prepared from thermoplastic polymers using precipitation techniques and formed into various shapes including hollow fibres or flat sheets.
The thermal precipitation technique for membrane formation commences with the formation of a solution of a thermoplastic polymer in a solvent at an elevated temperature. The solution is then cooled and, at a specific 15 temperature which depends on the polymer, the solvent, the o *concentration of the polymer in the solvent and the rate of cooling, phase separation occurs and the liquid polymer separates from the solvent.
All practical precipitation methods follow the same general process which is reviewed by Smolders et al in Kolloid Z.u.Z. Polymere 43, 14-20 (1971). The article distinguishes between spinodal and binodal decomposition of a polymer solution.
When the solution of a polymer in a solvent is allowed to cool at an infinitely slow rate, a temperature is reached, below which phase separation occurs and the liquid polymer WO 90/05007 PCT/AU89/00481 -2separates from the solvent. This is called binodal decomposition of the polymer solution.
When the rate of cooling is finite, the temperature at which phase separation occurs is generally lower than in the case of binodal decomposition. This is called spinodal decomposition of the polymer solution.
For practical purposes, all precipitation processes must be reasonably fast and so fall into the category of spinodal decomposition.
In most processes, the relative polymer and solvent concentrations are such that phase separation results in fine droplets of solvent forming in a continuous polymer phase.
these fine droplets form the pores of the membrane. As cooling continues, the polymer freezes around the solvent droplets. When phase separation occurs there is still some solubility of the polymer in the solvent and solvent in the polymer.
As the temperature is lowered, these solubilities decrease, and more and more solvent droplets appear in the polymer matrix. Crystallization of the droplets within the polymer results in shrinkage and cracking, thus forming interconnections between the pores. Finally, the solvent is removed from the pores.
Known precipitation methods of porous membrane formation depend on the liquid polymer separating from the solvent followed by cooling so that the solidified polymer SWO 90/05007 PCT/AU89/00481 -3can then be separated from the solvent. Whether the solvent is liquid or solid when it is removed from the polymer depends on the temperature at which the operation is conducted and the melting point of the solvent.
True solutions require that there be a solvent and a solute. The solvent constitutes a continuous phase, and the solute is distributed randomly in the solvent at a molecular level. Such a situation is almost unknown with polymer solutions. Long polymer chains tend to bend back on themselves and form temporary interactions or bonds with other polymer chains with which they come into contact.
These interactions are continually forming and breaking, and new ones are formed. Polymer solutions are thus rarely true solutions but lie somewhere between true solutions and mixtures.
In many cases it is also difficult to state which is the solvent and which is the solute. In the art, it is accepted practice to call a mixture of polymer and solvent a solution if it is optically clear without obvious inclusions of either phase in the other. Phase separation is usually then taken to be that point where there is an optically detectable separation.
There is yet another case where the heated mixture of polymer, solvent, and other components if present, is neither a solution nor a mixture in the usual sense of the words.
This is the case where a surface-active agent is present in sufficient concentration to form ordered structures such as micelles.
WO 90/05007 PC/AU89/00481 -4- In U.S. Specification 3,378,508, a polymer As heated with a solvent that is an anionic surfactant. The solution is then cooled and membrane formation results which is in accordance with the teachings of the spinodal decomposition technique. As the anionic surfactant solvent is a solid at room temperature, solvent removal is by removal of the solid surfactant from the pores.
U.S. Specification 4,247,498 describes the use of the spinodal decomposition technique with slow cooling of the solution in relation to a wide range of polymers and solvents. According to U.S. specification 4,247,498, the slow cooling of the solution allows the solvent droplets to coalesce somewhat before the polymer freezes around them. As the solution is cooled, more and more solvent droplets are formed. Their rate of coalescence is governed by the rate of diffusion of solvent through the liquid polymer matrix. A longer time at a higher temperature allows a greater diffusion of the solvent. The slow cooling also affects the rate at which crystal nuclei form in the polymer. The result is a membrane containing large cells interconnected by fine channels. The porous material of U.S. Specification 4,247,498 is extruded into air to form a block having a skin over its surface.
U.S. Specification 4,564,448 discloses a porous surface achieved by the technique of extruding the polymer solution into a bath of the solvent used forming the solution with the temperature of the bath being above the temperature where phase separation occurs.
L
SW0,90/05007 PCT/AU89/00481 U.K. Specification 2,115,425 discloses a spinodal decomposition technique with the modification that the solvent for the polymer is a mix of solvents, one of which is a very good solvent for the polymer and the other is a poor solvent. The ratio of the two solvents is adjusted to obtain a composite solvent that has the desired temperature related solvency effect for the polymer. Variation in the ratio of the two solvents affects the structure of the resultant membrane.
The process disclosed in abovementioned U.S. Patent 3,378,508 consists of heating a mixture of a solid thermoplastic polymer of mono-ethylenically unsaturated hydrocarbons, and, a water-soluble anionic surfactant to a temperature where the polymer and surfactant are mutually soluble, cooling the mixture to a temperature where the polymer and surfactant form two intermingled separate phases, and, dissolving the surfactant phase from the polymer.
According to U.S. Specification 3,378,508, the hydrocarbon and surfactant are mixed at elevated temperatures at which the two materials are mutually soluble to obtain a completely uniform distribution of the surfactant in the 4 polymer. The specification discloses that any water soluble anionic surfactants and solid, thermoplastic polymers of mono-ethylenically unsaturated hydrocarbons form a homogeneous mixture at a temperature determined by the higher of either the melting point of the surfactant or the softening temperature of the polymer.
i 1. LC, !l lll WO 90/05007 PCT/AU89/00481 -6- U.S. Specification 3,378,507 details attempts made to incorporate into polyethylene non-ionic and cationic surfactants such as nonylphenoxypoly(oxyethylene) ethanol, polyoxyethylated fatty alcohols, polyoxyethylated fatty acids, polyoxyethylated vegetable oil, copolymers of polyoxyethylene and polyoxypropylene, polyethylene glycol ethers and mixed alkyl amine salts containing an average of 18 carbon atoms in the aklyl group.
The non-ionic surfactants were found to be incompatible with polyethylene and would not mix with polyethylene.
Although the cationic surfactants could be milled into the polyethylene, the cationic surfactant could not then be washed out by water, ethanol or other solvents.
Contrary to the teachings of U.S. patent 3,378,507, we have found that certain cationic and non-ionic surfactants can be used to form porous materials. For example, whereas the U.S. specification states that nonylphenoxypoly(oxyethylene) ethanol cannot be used, we have found that at least some of that class of surfactant can be used.
An influencing factor is the polarity of the cationic or non-ionic surfactant which can be described in relation to the hydrophilic-lipophilic balance of the surfactant. Within a certain hydrophilic-lipophilic balance range we have found that there is no restriction on the type of surfactant than can be used to form porous membranes from a polymeric solution.
I_ -6a- The term "hydrophilic-lipophilic balance" or "HLB" is used throughout the description and claims of the present specification to express as a number the balance between the hydrophilic and lipophilic groups in a surfactant molecule.
A surfactant that is lipophilic in character will have a low HLB value while a hydrophilic surfactant will have a high HLB value. HLB values range from 1 to about 40 the balance point being about *0 0/ i 1 9 -7- DISCLOSURE OF THE INVENTION According to the invention there is provided a method of making a porous polymeric material comprising the steps of a) heating a mixture comprising: a polyolefin and, (ii) cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of to 6.0 to a temperature and for a time sufficient for polymer and surfactant to 10 mutually dissolve, b) cooling the mixture to a temperature so that nonequilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the polymer and surfactant in which the polymer and 15 surfactant form two intermingled separate phases of large interfacial surface area and, S" c) removing the surfactant phase from the polymer.
Sa The hydrophilic-lipophilic balance values mentioned above are relatively low for surfactants in other words, the surfactants which are suitable are relatively hydrophobic lipophilic). Surfactants with hydrophilic-lipophilic balance values lower than the preferred range have too good a solvency for the membrane to form when the dope is quenched, and surfactants with higher hydrophilic-lipophilic balance values will not dissolve the polymer.
Nonylphenoxypolyethylene glycols (which are also called nonylphenoxypoly(oxyethylene) ethanols) are represented by WO 90/05007 PCT/AU89/00481 -8the graphical formula
O-(C
2
H
4 0)nH
(I)
CgH 19 The second member of the series, where n 2, nonyphenoxyethoxyethanol is a preferred surfactant of the present invention and is the most prevalent member of the series in a mixture of nonylphenoxypolyethylene glycols that make up a commercially available solvent TERIC N2 (TERIC is a Registered Trade Mark). Nonylphenoxyethoxyethanol is represented by the graphical formula:-
O-C
2
H
4 0C 2
H
4 0H
(II)
C
9
H
19 Solvents in this series represent a distribution of nonylphenoxypolyethylene glycols. The Snonylphenoxypolyethylene glycols are initially a mixture represented by a Poissonian distribution, however, the exact distribution of the final product depends on further i, WO 90/05007 PCT/AU89/00481 -9processing such as distillation of low boiling point components to give the material as provided by the supplier.
The second member of the series can be used in the process of the invention to provide a porous structure but as n increases above 2 the material becomes more and more polar and will not produce porous structures when used in the process of the invention. In the case of TERIC N2, the preferred range of the hydrophilic-lipophilic balance is 5.6 to 5.8.
Another solvent which may be used is SYNPROLAM 35X2 which is an amine ethoxylate of the general formula:-
(CH
2
CH
2 0) H
(CH
2
CH
2 O)yH where x y 2 to 50 and R is a mixture of C 13 and fatty radicals in the approximate ratio of 70:30 about half of which are linear and the rest mostly branched species. In the case of SYNPROLAM 35X2, x+ y 2. Yet another solvent which may be used is BRIJ 92 which is a polyoxyethylene (2) oleyl alcohol. SYNPROLAM and BRIJ are Registered Trade Marks.
Other solvents having a hydrophilic-lipophilic balance in the range of 4.0 to 6.0 which may be used in carrying out the process of the invention include:-
I)
ethyloxylated derivatives of cetyl-oleyl alcohol such as TERIC 17A2 condensates of ethylene oxide with tall oil such as TERIC T2 self-emulsifying derivatives from high molecular weight fatty acids such as TERIC 124 sorbitan monooleate sorbitan monostearate POE cetyl oleyl alcohol such as ATLAS G-70140 10 ATMER 685 nonionic surfactant POE cetyl alcohol POE stearyl alcohol POE fatty alcohols such as CIRRASOL EN-MB and CIRRASOL EN-MP POE synthetic primary 013/015 alcohol S• such as RENEX 702 ATLAS, ATMER, CIRRASOL and RENEX are Registered Trade Marks.
Although the preferred polyolefin is polypropylene, other polyolefins such as polybutylene may be used.
In a preferred form of the invention, the porous polymeric material is formed as a hollow fibre using a quadruple co-extrusion head having four concentric passageways. The axial passageway receives a lumen forming fluid, the next outward passageway contains a homogenous mixture of the polymer and a surfactant solvent to form the membrane, the next outwardly concentric passageway has a
IP
-11coating fluid and the outermost passageway has a cold quench fluid. The lumen, coating and quenching fluids do not contain the surfactant.
Each fluid is transported to the extrusion head by means of individual metering pumps. The four components are individually heated and are transported along thermally insulated and heat traced pipes. The extrusion head has a number of temperature zones. The lumen fluid, membrane dope and coating fluid are brought to the same temperature in a 10 closely monitored temperature zone where the polymer solution making up the dope is shaped. The quench fluid is introduced in a cooling zone where the dope undergoes non-equilibrium liquid-liquid phase separation to form a bicontinuous matrix of large interfacial surface area of two liquids in which c,,
*S
FI
t r I"i r; WO90/05007 PCT/AU89/00481 -12the polymer phase is solidified before aggregated separation into distinct phases of small interfacial surface area can take place.
The hollow fibre membrane leaves the extrusion head completely formed and there is no need for any further formation treatment except for removing the surfactant solvent from the membrane in a post-extrusion operation that is common to membrane manufacturing processes. A volatile solvent that does not dissolve the polymer is used to remove the surfactant solvent for the polymer from the finished membrane.
The lumen forming fluid may be selected from a wide variety of substances such as soybean oil and an inert gas such as nitrogen. The same substance may be used as the coating and quenching fluids. Water may be used as the quenched fluid. Other substances which may be used as the lumen forming material, the coating fluid and the quenching fluid include:paraffin oil peanut oil teel oil boleko oil oil of mustard olive oil seneca oil coconut oil coffee oil WO 90/05007 PCT/AU89/00481 -13rapeseed oil corn oil cottonseed oil glycerol glyceryl trioleate trimyrlstin jojoba oil macassar oil neem oil castor oil orris root oil safflower oil oleic, palmitic, stearic, arachidic, arachidonic, behenic, lignoceric, linoleic, linolenic, elaidic, vaccenic acids and their glycerides, and mixed with their sodium, potassium and calcium salts dioctylphthalate and other phthalate esters of alcohols of six carbon atoms or more.
The homogenous mixture of the thermoplastic polymer and surfactant solvent dope) may include an anti-oxidant.
In the case of polypropylene, the preferred anti-oxidant is ETHANOX 330 (ETHANOX is a Registered Trade Mark) which has the chemical name 1,3,5,-trimethyl-2,4,6-tris-3,5-di-tertbutyl-4-hydroxybenzyl)benzene. Any hindered phenol which dissolves in the dope could be used.
I below which phase separation occurs and the liquid polymer 7 WO 90/05007 PCT/AU89/00481, -14- It has been found that in the case of the polypropylene/TERIC N2 system, the concentration of the polymer in the dope may be from 15% to 50% weight by weight although the preferred range is 20% to 40% weight by weight.
Solvent viscosity may be in the range of 10 to 1000 mPa.s and the quench liquid viscosity may be from 20 to 100 mPa.s although 50 to 70 mPa.s is preferred. Using the extrusion apparatus described above, the hollow fibre may be extruded at a rate of 40 to 120 metre/minute although the preferred range is 50 to 85 metre/minute.
The hollow fibre membrane of the invention is characterised by a lacey or filamentous structure.
In this specification, the term "lacey" means that the membrane is made up of a plurality of polymer strands connected together at a number of locations along each strand. Each connection point has only slightly larger dimensions than the cross-section of the strands. The length of each strand is from 5 to 50 times the diameter of the strand and the strands vary in cross-sectional shape from circular to elliptical, in the latter case the major axis of the ellipse may be up to 5 times the minor axis of the ellipse. The description "lacey or filamentous structure" t may also be visualised as a three dimensional rounded lace filet derived from a bicontinuous structure.
In a preferred form of the invention, the hollow fibre membrane has a lacey structure in which there is some slight orientation of the strands in the axial direction of the fibre so that when a lumenal gaseous blowback procedure is i.
b WO90/05007 PCT/AU89/00481 Implemented to clean the fibres, certain dimensions of the interstices increase on average allowing any material lodged in the interstices to be easily dislodged. The Interstices are of a generally axially elongated shape and when the gaseous blowback is applied, the interstices distort from the axially elongated shape into a generally square shape to enlarge the minimum dimension of the interstices. The gaseous blowback will also stretch the fibre to increase the minimum dimension of the interstices.
In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings in which:- Fig. 1 is a phase diagram for a generalised polymer/solvent system, and Fig. 2 is a schematic micrographic representation of the structure of the porous polymeric material according to one embodiment of the present invention.
Fig. 1 is a temperature-composition phase diagram for a generalised polymer/solvent system showing liquid-liquid and solid-liquid phase separation. The abscissa represents composition of the mixture ranging from no polymer at the left to all polymer at the right. The ordinate represents temperature. To the right of the diagram, line 10 which slopes upwards at a straight oblique angle represents division between complete solution above the line and solid- WO 90/05007 PCT/AU89/00481 liquld separation below the line. The region above line extends to the left of the diagram over the top of upwardly convex line or curve 11 so that all of the top of the diagram above lines 10 and 11 represents conditions that result in complete solution of the polymer in the solvent.
Under curve 11 is an upwardly convex dashed line 12 that represents the division between liquid-liquid nonequilibrium phase separation above line 12 and liquid-liquid equilibrium phase separation below line 12. Line 12 is shown dashed because the actual location of the line is indistinct.
The region between the dashed lines 12 and the solid line 11 is a metastable region above which the components must form one phase and below which the components must form distinct liquid phases. The region between the horizontal dash-dot line 13 and solid line 11 is the miscibility gap.
The solid line 11 represents phase separation when the temperature is lowered infinitely slowly, and the dashed line 12 represents phase separation when the temperature is lowered infinitely rapidly. Because the manufacturing process of the invention is a non-equilibrium process, it passes from a point above the miscibility gap through the binodal curve (so'id line 11) into the metastable region in the vertical direction, and somewhere in that region the liquid-liquid bicontinuous matrix forms, and continuing vertically down through the spinodal curve (dashed line 12) into the liquid-liquid region, and further down past the WO90/05007 PCT/AU89/00481 -17dash-dot line 13 where the polymer rich phase solidifies, to a point somewhere in the solid-liquid region.
The position along the horizontal axis where the quench is performed determines what structure is obtained. A granular structure generally occurs from positions to the left of the apex of the binodal and spinodal curves. A granular structure is in our view of little commercial value for microporous membranes using gaseous backwash. Our process uses conditions to the right of the apex of the binodal and spinodal curves which result in a lacey structure. In our view any membrane produced by thermal precipitation that has a lacey structure must have been made by spinodal decomposition.
Fig. 2 schematically represents a three-dimensional photomicrograph taken of a preferred porous polymeric material prepared according to the method of the present invention. The darkened regions 14 represent solid polymeric material at the surface of the image. The lined regions represent solid polymeric material slightly below the surface of the image. The dotted regions 16 represent polymer bridges well below the surface of the image. The blank regions represent the alveolar structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will now be described with reference to the production of porous hollow fibre membranes.
-i :1 -j I, IPuu'ienng temperature of the polymer.
WO 90/05007 PCT/AU89/00481, -18- EXAMPLE 1 A dope was formed by mixing and then heating 2600 gram of polypropylene pellets, 7300 gram of TERIC N2 and 100 gram of anti-oxidant ETHANOX 330. The temperature of the dope was raised to above 2200 with agitation under vacuum to ensure that that the mixture became homogeneous. The dope was then extruded through the quadruple passage die at a temperature of 220 0
C.
Nitrogen was used as the lumen forming fluid and soybean oil as the coating fluid and quenching fluid. The dope flow rate was 22cc/min, the lumen pump flow rate 7.6 cc/min, the coating pump flow rate 5.0 cc/min and the quench pump flow rate was 1750 cc/min.
The circularity of the fibre prior to extraction of the solvent was 95% and the break extension was 175%. After extracting the solvent, the physical characteristics of the fibre were:- Lumen 340 micron Outer diameter 640 micron Circularity Concentricity Bubble Point >170kPa S% pores above 0.16 micron Mean pore size 0.20 micron Water Permeability at 50 kPa >40 cc/min/m Yield force 0.8 N WO 90/05007 PCT/AU89/00481 -19- Break force 1.0 N Break extension 150% Surface pore width (nominal) 1 micron The structure of the fibre so formed was generally lacey.
The lacey structure does not lend itself to a precise qualitative description in terms used to describe prior art membranes such as cells and pores. In the prior art such as U.S. patent 4,519,909, cells relate to spheres and pores relate to cylinders. In some respects, the parts of the lacey structure where one cavity intersects another may be equivalent to a "cell" and the actual intersection itself a "pore". Topologically, such "cells" of the lacey structure relate to adjacent spheres and such "pores" relate to circles formed by their intersection whereas in the prior art the cells relate to separated spheres and the pores relate to the connecting cylinders.
As well as such "pores" and "cells", the lacey structure has alveoli which are larger cavities than cells and these connect to a larger number of "cells". The lacey structure occupies the spaces between the alveoli.
A typical lacey structure may have substantially spherical "cells" of between 0.1 to 5 micron which have substantially circular "pores" of 0.1 to 0.5 micron interconnecting the cells to each other. The "pores" also connect the cells to alveoli of about 8 to 20 micron.
WO 90/05007 PC/AU89/0481, Water Permeability tests showed that the permeability of a typical fibre from outside to lumen was one third of the permeability from lumen to outside.
Although the invention has been described in relation to a polypropylene/TERIC N2 solution, it is to be understood that the invention is not limited thereto. Soybean oil with or without castor oil may be added to the solution as co-solvent and SYNPROLAM 35X2 or BRIJ 92 may be used instead of TERIC N2. A solvent may be added to the coating fluid.
Surface pore modification may be effected by both temperature control and variation of the composition of the coating fluid. Membranes can be prepared having elongated pores in the axial direction but with symmetrical morphology in the radial and circumferential directions. Surface porosity can be varied in radial porosity from a "skin" through to complete radial isotropy and further to having a surface that is more porous than the remainder of the membrane (reverse asymmetry).
During extrusion, the coating fluid mixes significantly with the molten polymer solution to a greater extent than the quench fluid mixes when the coating fluid is omitted. The coating fluid controls the surface porosity of the membrane.
The hot coating fluid ameliorates the sudden cooling effect of the quench fluid on the dope. The coating fluid is a separate, co-extrusion, and is neither part of the membrane extrusion nor the quench co-extrusion.
I l WO,90/05007 PCT/AU89/00481 -21- Although the precise mechanism of the structure formation is not clear, it would seem that a liquid-liquid bicontinuous system is formed which if maintained for sufficient time would become two separate layers. During this process, the system could be made to pass through a lacey structure followed by a stage of nearly spherical cells with interconnecting pores. For a given polymer and solvent mix, the size range of the cells depends on cooling rate and the interfacial surface tension between the polymer rich and the polymer lean phases while the pore size depends on cooling rate and, to a lesser extent, molecular weight of the polymer.
It is to be noted that the fibre travels down the quench tube at a significantly different linear speed from the quench fluid. The extruded fibre travels at a speed three to four times faster than the average speed of the quench fluid. Such a speed difference calculated on the average speed also means that the fibre travels at a speed about double the maximum speed of the quench fluid. The average and maximum speed of the quench fluid above are taken as the speed with no fibre present.
Although the above example refers to the use of nitrogen as the lumen forming fluid, any saturated vapour may be used as may a wide variety of liquids. When nitrogen (or a saturated vapour) is used,, it has the effect of reducing the lumenal surface pore size, giving greater asymmetry. Use of a saturated vapour has the property that it will condense i Moir WO 90/05007 Pcr/AU89/00481 -22in the lumen under cooling, allowing the quench fluid to pass through the porous walls, and give some measure of mechanical compression to the solidifying membrane.
EXAMPLE 2 5.2 kg Hoechst polypropylene PPN1060F was dissolved in 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 230°C with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 31.30C.
The dimensions of the fibre were 322 micron lumen diameter and 671 micron outside diameter.
The resulting fibre had a water permeability of 106 ml/min/m at 96 kPa, 367 ml/min/m at 398 kPa, and 478 ml/min/m at 599 kPa, a mean pore size of 0.301 micron and 90.7% pores above 0.16 micron.
EXAMPLE 3 5.2 kg Hoechst polypropylene PPN1060F was dissolved in 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 230°C with soybean oil as the lumen,coating and quench fluids. The quench fluid temperature was 29.90C.
The dimensions of the fibre were 324 micron lumen diameter and 652 micron outside diameter.
The resulting fibre had a water permeability of 126 ml/min/m at 96 kPa, 430 ml/min/m at 398 kPa, and 543 ml/min/m at 599 kPa, a mean pore size of 0.380 micron and 95.2% pores above 0.16 micron.
WO 90/05007 PCT/AU89/00481 -23- EXAMPLE 4 5.2 kg Hoechst polypropylene PPN1060F was dissolved in 14.6kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 230°C with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 31.70C.
The'dimensions of the fibre were 323 micron lumen diameter and 640 micron outside diameter.
The resulting fibre had a water permeability of 94 ml/min/m at 95 kPa, 330 ml/min/m at 396 kPa, and 448 ml/min/m at 598 kPa, a mean pore size of 0.310 micron and 87.9% pores above 0.16 micron.
EXAMPLE 5.2 kg Hoechst polypropylene PPN10O0F was dissolved in 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and Extruded at a temperature of 23000 with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 31.8 0
C.
The dimensions of the fibre were 320 micron lumen diameter and 627 micron outside diameter.
The resulting fibre has a water permeability of ml/min/m at 98 kPa, 288 ml/min/m at 399 kPa, and 393 ml/min/m at 600 kPa, a mean pore size of 0.260 micron and 80.9% pores above 0.16 micron.
EXAMPLE 6 5.2 kg Hoechst polypropylene PPN1060F was dissolved in WO90/05007 PCT/AU89/00481 -24- 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 230 0 C with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 30.5 0
C.
The dimensions of the fibre were 325 micron lumen diameter and 642 micron outside diameter.
The resulting fibre had a water permeability of 73 ml/min/m at 98 kPa, 288 ml/min/m at 399 kPa, and 393 ml/min/m at 600 kPa, a mean pore size of 0.260 micron and 80.9% pores above 0.16 micron.
EXAMPLE 7 6.75 kg Hoechst polypropylene PPN1060F was dissolved in 18.25 kg TERIC N2 with 0.25 kg antioxidant Ethanox 330 and extruded at a temperature of 23000 with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 30.1 0
C.
The nominal dimensions of the fibre were 320 micron lumen diameter and 650 micron outside diameter.
The resulting fibre had a water permeability of 68 ml/min/m at 95 kPa, 288 ml/min/m at 402 kPa, and 347 ml/min/m at 600 kPa, a mean pore size of 0.270 micron and 80.1% pores above 0.16 micron.
EXAMPLE 8 5.2 kg Hoechst polypropylene PPN1060F was dissolved in 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 23000 with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 31.50C.
The dimensions of the fibre were 310 micron lumen diameter and 599 micron outside diameter.
The resulting fibre had a water permeability of 52 ml/min/m at 96kPa, 241 ml/min/m at 397 kPa, and 305 ml/min/m at 598 kPa, a mean pore size of 0.322 micron and 65.7% pores above 0.16 micron.
EXAMPLE 9 10 5.2 kg Hoechst polypropylene PPN1070 was dissolved in 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of .960C with soybean oil as the lumen, coating and quench fluids. The quench fluid I temperature was 25.40C.
15 The nominal dimensions c, the fibre were 320 micron lumen diameter and 650 micron outside diameter.
The resulting fibre had a bubble point of 140 kPa, a S mean pore size of 0.24 micron and 89.6% pores above 0.16 micron.
EXAMPLE 4.8 kg Hoechst polypropylene PPN1070 was dissolved in 15.0 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 1980C with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 20.70C.
The nominal dimensions of the fibre were 320 micron lumen diameter and 650 micron outside diameter.
Li -26- The resulting fibre had a bubble point of 175 kPa, a mean pore size of 0.23 micron and 82.8% pores above 0.16 micron.
EXAMPLE 11 5.2 kg Hoechst polypropylene PPN1060F was dissolved in 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 2380C with soybean oil as the lumen, coating and quench fluids. The quench fluid temperature was 21.40C.
10 The nominal dimensions of the fibre were 320 micron 0 S* lumen diameter and 650 micron outside diameter.
0: The resulting fibre had a bubble point of 280 kPa, a 0** 0 mean pore size of 0.18 micron and 83.4% pores above 0.16 micron.
15 EXAMPLE 12 000 !5.2 kg Shell polypropylene LY6100 was dissolved in 14.6 kg TERIC N2 with 0.2 kg antioxidant Ethanox 330 and extruded at a temperature of 1900C with dioctylphthalate as the lumen, coating and quench fluids. The quench fluid temperature was 26.50C.
The nominal dimensions of the fibre were 320 micron lumen diameter and 650 micron outside diameter.
The resulting fibre had a bubble point of 310 kPa a mean pore size of 0.24 micron and 79% pores above 0.16 micron.
Claims (32)
1. A method of making a porous polymeric material comprising the steps of:- heating a mixture comprising: a polyolefin and, (ii) a cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of to 6.0 to a temperature and for a time sufficient for the polymer and surfactant to mutually dissolve, cooling the mixture to a temperature so that non- equilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the *0 polymer and surfactant so that the polymer and surfactant form two intermingled separate phases, of large interfacial surface area, and, removing the surfactant phase from the polymer.
2. A method according to claim 1 wherein the molten 0* mixture is introduced into an extrusion head adapted to shape the molten mixture into a hollow fibre.
3. A method according to claim 2 and including the step of introducing a lumen-forming fluid into the lumen of the shaped molten mixture.
4. A method according to claim 2 or claim 3 and including the step of introducing a coating fluid around the outer surface of the shaped molten mixture.
A method according to claim 4 and including the step of _K7 introducing a cooling fluid around the coating fluid. \l e -28-
6. A method according to claim 2 wherein the extrusion head has a first temperature zone in which the fibre is formed and a second temperature zone in which the formed fibre is cooled and solidified.
7. A method according to claim 6 wherein the lumen-forming fluid and the coating fluid are introduced into the extrusion head at the first temperature zone and the cooling fluid is introduced into the extrusion head at the second temperature zone.
8. A method according to claim 2 wherein the diameter of :the fibre is reduced after formation of the hollow fibre *form, the ratio of the initial diameter of the fibre to that of the final diameter being in the range of from 1.4 to
9. A method according to claim 5 wherein the fibre travels through the extrusion head at a different linear speed to ge1 **that of the cooling fluid. So:
10. A method according to claim 9 wherein the fibre travels at a speed 3 to 4 times faster than the average speed of the gos cooling fluid.
11. A method according to claim 3 wherein the lumen- forming fluid is nitrogen gas or a saturated vapour.
12. A method according to claim 4 wherein the coating fluid is selected from the group comprising soybean oil, paraffin oil, peanut oil, teel oil, boleko oil, oil of mustard,olive oil, seneca oil, coconut oil, coffee oil, rapeseed oil, corn oil, cottonseed oil, glycerol, glyceryl trioleate, -29- trimyristin, jojoba oil, macassar oil, neem oil, castor oil, orris root oil and safflower oil and oleic, palmitic, stearic arachidic, arachidonic, behenic, lignoceric, linoleic, linolenic, elaidic, vaccenic acids and their glycerides, and mixed with their sodium, potassium and calcium salts.
13. A method according to claim 5 wherein the cooling fluid is selected from the group comprising soybean oil, water, paraffin oil, peanut oil, teel oil, boleko oil, oil of mustard, olive oil, seneca oil, coconut oil, coffee oil, rapeseed oil, corn oil,cottonseed oil, glycerol, glyceryl g*o: trioleate, trimyristin, jojoba oil, macassar oil, neem oil, S. castor oil, orris root oil, and safflower oil and oleic, *0* palmitic, stearic, arachidic, arachidonic, behenic, lignoceric, linoleic, linolenic, elaidic, vaccenic acids and their glycerides, and mixed with their sodium, potassium and calcium salts.
S14. A method according to claim 13 wherein the cooling fluid is the same as the coating fliud.
15. A method according to claim 14 wherein the lumen- forming fluid is the same as the coating fluid and the cooling fluid.
16. A method according to claim 7 wherein the lumen-forming fluid and the coating fluid are heated to the temperature of the molten mixture before being introduced into the extrusion head.
17. A method according to claim 1 wherein the polymer is selected from the group comprising polypropylene and polybutylene.
18. A method according to claim 1 wherein the surfactant is selected from the group comprising nonylphenoxyethoxyethanol, an amine ethoxylate, a polyoxyethylene(2)oleyl alcohol, ethyloxylated derivatives of cetyl-oleyl alcohol, condensates of ethylene oxide with tall oil, self-emulsifying derivatives from high molecular weight fatty acids, sorbitan monooleate, sorbitan monostearate, POE cetyl-oleyl alcohol, ATMER 685 nonionic surfactant, POE cetyl alcohol, POE stearyl S alcohol, POE fatty alcohols and POE synthetic primary C013/C15 alcohol.
19. A method according to any one of the preceding claims wherein the fibre forming mixture includes an anti-oxidant.
20. A method according to claim 19 wherein the anti-oxidant S* is selected from the group comprising (1,3,5,-trimethyl- 2,4, 6 -tris-3,5-di-tert-butyl-4-hydroxybenzyl)benzene and a dissolvable hindered phenol.
21. A method according to claim 1 wherein the polymer is polypropylene and the solvent is nonylphenoxyethoxyethanol and wherein the concentration of the polymer in the solvent is from 15% to 50% weight by weight. -31-
22. A porous polyolefin material prepared by the method of claim 1 and characterised by a lacey or filamentous structure consisting of a plurality of polymer strands connected together at spaced apart locations along each strand.
23. A porous material according to claim 22 wherein the dimension of the connection is only slightly larger than the cross-section of the strands at the connection point.
24. A porous material according to claim 22 or claim 23 wherein the length of each strand is from 5 to 50 times the diameter of the strand. too
25. A porous material according to any one of claims 22 to 24 wherein the cross-sectional shape of at least some of the strands is circular.
26. A porous material according to any one of claims 22 to :24 wherein the cross-sectional shape of at least some of the 0 strands is elliptical.
27. A porous material according to claim 26 wherein the s o major axis of the ellipse is up to 5 times the minor axis of the ellipse.
28. A porous material according to any one of claims 22 to 27 in which at least some of the strands are oriented in the axial direction and the interconnected axial directed strands define interstices of a generally prolate shape.
29. A porous material according to any one of claims 22 to 28 wherein the structure includes a plurality of cells of from 0.1 to 5 micron which are connected together by pores -9i a I-$ -32- of from 0.1 to 0.5 micron and a plurality of alveoli of from 8 to 20 micron.
A porous material according to claim 29 wherein each alveous is connected to a large number of cells.
31. A porous material according to claim 29 or claim wherein the lacey structure occupies the spaces between the alveoli.
32. A porous material according to any one of claims 22 to 31 in the form of a hollow fibre. A method of making a porous polyolefin material :..substantially as hereinbefore described with reference to the DAE hs1t day of December, 1991. ",MEMTEC LIMITED Patent Attorneys for the Applicant: PETER MAXWELL &ASSOCIATES. -IA4
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU46227/89A AU621428B2 (en) | 1988-11-10 | 1989-11-10 | Porous membranes |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPJ139588 | 1988-11-10 | ||
AUPJ1395 | 1988-11-10 | ||
AU46227/89A AU621428B2 (en) | 1988-11-10 | 1989-11-10 | Porous membranes |
Publications (2)
Publication Number | Publication Date |
---|---|
AU4622789A AU4622789A (en) | 1990-05-28 |
AU621428B2 true AU621428B2 (en) | 1992-03-12 |
Family
ID=25627542
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU46227/89A Expired AU621428B2 (en) | 1988-11-10 | 1989-11-10 | Porous membranes |
Country Status (1)
Country | Link |
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AU (1) | AU621428B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1882005A1 (en) * | 2005-05-16 | 2008-01-30 | SK Energy Co., Ltd. | Microporous polyethylene film through liquid-liquid phase separation mechanism and preparing method thereof |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3378507A (en) * | 1961-12-20 | 1968-04-16 | Gen Electric | Producing microporous polymers |
US4401567A (en) * | 1980-10-14 | 1983-08-30 | Mitsubishi Rayon Co., Ltd. | Microporous polyethylene hollow fibers |
WO1986002282A1 (en) * | 1984-10-09 | 1986-04-24 | Millipore Corporation | Microporous membranes of ultrahigh molecular weight polyethylene |
-
1989
- 1989-11-10 AU AU46227/89A patent/AU621428B2/en not_active Expired
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3378507A (en) * | 1961-12-20 | 1968-04-16 | Gen Electric | Producing microporous polymers |
US4401567A (en) * | 1980-10-14 | 1983-08-30 | Mitsubishi Rayon Co., Ltd. | Microporous polyethylene hollow fibers |
WO1986002282A1 (en) * | 1984-10-09 | 1986-04-24 | Millipore Corporation | Microporous membranes of ultrahigh molecular weight polyethylene |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1882005A1 (en) * | 2005-05-16 | 2008-01-30 | SK Energy Co., Ltd. | Microporous polyethylene film through liquid-liquid phase separation mechanism and preparing method thereof |
EP1882005A4 (en) * | 2005-05-16 | 2012-06-27 | Sk Innovation Co Ltd | Microporous polyethylene film through liquid-liquid phase separation mechanism and preparing method thereof |
Also Published As
Publication number | Publication date |
---|---|
AU4622789A (en) | 1990-05-28 |
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Owner name: U.S. FILTER WASTEWATER GROUP, INC. Free format text: FORMER OWNER WAS: MEMTEC LIMITED |