USRE35360E - Reduction of molecular weight of poly(tetramethylene ether) glycol - Google Patents
Reduction of molecular weight of poly(tetramethylene ether) glycol Download PDFInfo
- Publication number
- USRE35360E USRE35360E US08/263,842 US26384294A USRE35360E US RE35360 E USRE35360 E US RE35360E US 26384294 A US26384294 A US 26384294A US RE35360 E USRE35360 E US RE35360E
- Authority
- US
- United States
- Prior art keywords
- molecular weight
- poly
- ptmeg
- tetramethylene ether
- glycol
- 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 - Lifetime
Links
- -1 poly(tetramethylene ether) Polymers 0.000 title claims abstract description 39
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 title claims description 29
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 title claims description 15
- 238000000034 method Methods 0.000 claims abstract description 55
- 238000006243 chemical reaction Methods 0.000 claims abstract description 51
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims abstract description 26
- 150000002148 esters Chemical class 0.000 claims abstract description 25
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims abstract description 13
- 229920000909 polytetrahydrofuran Polymers 0.000 claims abstract 8
- DTQVDTLACAAQTR-UHFFFAOYSA-N Trifluoroacetic acid Chemical compound OC(=O)C(F)(F)F DTQVDTLACAAQTR-UHFFFAOYSA-N 0.000 claims description 37
- 239000000203 mixture Substances 0.000 claims description 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- 239000002253 acid Substances 0.000 claims description 17
- 239000007858 starting material Substances 0.000 claims description 16
- 125000004432 carbon atom Chemical group C* 0.000 claims description 9
- ABDBNWQRPYOPDF-UHFFFAOYSA-N carbonofluoridic acid Chemical compound OC(F)=O ABDBNWQRPYOPDF-UHFFFAOYSA-N 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 239000011541 reaction mixture Substances 0.000 claims description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims 5
- 150000002334 glycols Chemical class 0.000 claims 4
- 125000004185 ester group Chemical group 0.000 claims 1
- 238000006136 alcoholysis reaction Methods 0.000 abstract description 17
- 230000007062 hydrolysis Effects 0.000 abstract description 9
- 238000006460 hydrolysis reaction Methods 0.000 abstract description 9
- 239000000178 monomer Substances 0.000 abstract description 2
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 30
- 239000003054 catalyst Substances 0.000 description 21
- 239000000047 product Substances 0.000 description 20
- VMVNZNXAVJHNDJ-UHFFFAOYSA-N methyl 2,2,2-trifluoroacetate Chemical compound COC(=O)C(F)(F)F VMVNZNXAVJHNDJ-UHFFFAOYSA-N 0.000 description 15
- 150000005690 diesters Chemical class 0.000 description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 8
- UQSQSQZYBQSBJZ-UHFFFAOYSA-N fluorosulfonic acid Chemical compound OS(F)(=O)=O UQSQSQZYBQSBJZ-UHFFFAOYSA-N 0.000 description 6
- 239000000395 magnesium oxide Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 238000011065 in-situ storage Methods 0.000 description 5
- 238000006116 polymerization reaction Methods 0.000 description 5
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 4
- WQDUMFSSJAZKTM-UHFFFAOYSA-N Sodium methoxide Chemical compound [Na+].[O-]C WQDUMFSSJAZKTM-UHFFFAOYSA-N 0.000 description 4
- 239000006227 byproduct Substances 0.000 description 4
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 4
- 230000007935 neutral effect Effects 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000009835 boiling Methods 0.000 description 3
- 239000000292 calcium oxide Substances 0.000 description 3
- 239000003153 chemical reaction reagent Substances 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 238000005227 gel permeation chromatography Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 3
- 239000002198 insoluble material Substances 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 125000005010 perfluoroalkyl group Chemical group 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 2
- 159000000007 calcium salts Chemical class 0.000 description 2
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 230000000379 polymerizing effect Effects 0.000 description 2
- 229920002635 polyurethane Polymers 0.000 description 2
- 239000004814 polyurethane Substances 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 125000000542 sulfonic acid group Chemical group 0.000 description 2
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
- LRMSQVBRUNSOJL-UHFFFAOYSA-N 2,2,3,3,3-pentafluoropropanoic acid Chemical compound OC(=O)C(F)(F)C(F)(F)F LRMSQVBRUNSOJL-UHFFFAOYSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 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 description 1
- 229920000557 Nafion® Polymers 0.000 description 1
- 101100386054 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) CYS3 gene Proteins 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- 125000005907 alkyl ester group Chemical group 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- RCPKXZJUDJSTTM-UHFFFAOYSA-L calcium;2,2,2-trifluoroacetate Chemical compound [Ca+2].[O-]C(=O)C(F)(F)F.[O-]C(=O)C(F)(F)F RCPKXZJUDJSTTM-UHFFFAOYSA-L 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 238000012656 cationic ring opening polymerization Methods 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010908 decantation Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 239000002638 heterogeneous catalyst Substances 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 238000012844 infrared spectroscopy analysis Methods 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 159000000003 magnesium salts Chemical class 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 238000006140 methanolysis reaction Methods 0.000 description 1
- 150000004702 methyl esters Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- YPJUNDFVDDCYIH-UHFFFAOYSA-N perfluorobutyric acid Chemical compound OC(=O)C(F)(F)C(F)(F)C(F)(F)F YPJUNDFVDDCYIH-UHFFFAOYSA-N 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000012429 reaction media Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 101150035983 str1 gene Proteins 0.000 description 1
- 229910052712 strontium Inorganic materials 0.000 description 1
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- WROMPOXWARCANT-UHFFFAOYSA-N tfa trifluoroacetic acid Chemical compound OC(=O)C(F)(F)F.OC(=O)C(F)(F)F WROMPOXWARCANT-UHFFFAOYSA-N 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000010977 unit operation Methods 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
- C08G65/32—Polymers modified by chemical after-treatment
- C08G65/329—Polymers modified by chemical after-treatment with organic compounds
- C08G65/331—Polymers modified by chemical after-treatment with organic compounds containing oxygen
- C08G65/332—Polymers modified by chemical after-treatment with organic compounds containing oxygen containing carboxyl groups, or halides, or esters thereof
- C08G65/3322—Polymers modified by chemical after-treatment with organic compounds containing oxygen containing carboxyl groups, or halides, or esters thereof acyclic
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C43/00—Ethers; Compounds having groups, groups or groups
- C07C43/02—Ethers
- C07C43/03—Ethers having all ether-oxygen atoms bound to acyclic carbon atoms
- C07C43/04—Saturated ethers
- C07C43/13—Saturated ethers containing hydroxy or O-metal groups
- C07C43/135—Saturated ethers containing hydroxy or O-metal groups having more than one ether bond
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G2650/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G2650/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule characterized by the type of post-polymerisation functionalisation
- C08G2650/12—Depolymerisation, e.g. to reform the monomer
Definitions
- the present invenuon relates to a process for reducing the average molecular weight of poly(tetramethylene ether) glycol (PTMEG) by reaction with certain perfluorocarboxylic acids, particularly trifluoroacetic acid.
- PTMEG poly(tetramethylene ether) glycol
- PTMEG is a commodity in the chemical industry, used mainly in the manufacture of polyurethanes and polyesters. Functioning as a chain segment, PTMEG imparts resilience, flexibility, and softness to these materials.
- PTMEG is manufactured by way of cationic ring-opening polymerization of tetrahydrofuran (THF) in the presence of a suitable cationic initiator such as fluorosulfonic acid.
- THF tetrahydrofuran
- the molecular weight of PTMEG significantly influences the physical properties of both the PTMEG and the products derived from it.
- PTMEG of relatively low molecular weight is a sticky, viscous oil at room temperature while, at higher molecular weights, it is thicker and more waxy.
- the molecular weight of PTMEG may be expressed as either a "number-average” or a "weight-average”.
- the number average molecular weight (Mn) is obtained by dividing the weight of a sample by the number of molecules of which it is composed.
- the weight-average molecular weight (Mw), on the other hand, is defined as the ratio of the sum of the mathematical products obtained by multiplying each molecular weight present in the sample by its corresponding fractional weight and the total sample weight.
- Mn and Mw are normally determined via such methods as gel permeation chromatography (GPC). Since a typical sample of PTMEG is composed of molecules of different degrees of polymerization, a distribution of molecular weights exists and as a result, values of Mn and Mw are not equivalent.
- the ratio Mw/Mn referred to as the polydispersity, is indicative of the breadth of distribution of molecular weights for a given sample of polymer.
- PTMEG may be produced with molecular weights in the millions, the most useful commercial varieties are those with number average molecular weights in the range between about 250 and 3500.
- the most common method of producing PTMEG with a Mn in this range is by polymerizing THF in the presence of fluorosulfonic acid (FSA). That method has several disadvantages however.
- FSA fluorosulfonic acid
- the FSA used in the polymerization cannot be recovered for reuse and the disposal of the toxic and corrosive spent acids, sulfuric acid and hydrofluoric acid, produced as a by-product present a serious environmental problem.
- the PTMEG product may contain some small but significant number of fluorine end groups.
- esters of PTMEG through polymerization of THF in a medium containing an acylium ion precursor such as acetic anhydride, a polymeric catalyst which contains sulfonic acid groups, and optionally, a carboxylic acid such as acetic acid.
- an acylium ion precursor such as acetic anhydride
- a polymeric catalyst which contains sulfonic acid groups
- a carboxylic acid such as acetic acid
- the present invention relates to a process for reducing the average molecular weight of PTMEG without significant conversion of PTMEG to THF. It is essentially a two-step procedure, the first of which comprises reacting PTMEG with a perfluoroalkyl carboxylic acid to form a perfluoroalkyl ester of PTMEG. That ester is, in the second step, converted back to PTMEG by hydrolysis or less preferably alcoholysis of the ester end groups.
- the PTMEG obtained as a product of the present invention is a lower number average molecular weight relative to the average molecular weight of the PTMEG used as starting material.
- the alcoholysis reaction produced an alkyl ester of the perfluorocarboxylic acid which can be separately converted by alcoholysis or hydrolysis so as to regenerate the perfluorocarboxylic acid required for the first step of the process.
- the two primary steps of the process of this invention can be represented by the chemical reactions described below.
- the high molecular weight PTMEG used as a starting material is designed “HMW PTMEG”
- the lower molecular weight ester formed in the first step of the process is designated “LMW PTMEG Ester”
- the PTMEG produced by the process is designated as "LMW PTMEG”.
- the two esters differ in their chain lengths.
- One of the LMW PTMEG esters has (n-x) oxytetramethylene repeat units while the other has x units.
- Rf is a perfluoroalkyl group containing one to three carbon atoms
- n and x are the number of oxytetramethylene repeating units of the HMW PTMEG and LMW PTMEG ester molecules, respectively, the difference of which is the number of repeating units for the other LMW perfluoroalkyl ester molecule.
- Reaction 1 the HMW PTMEG, perfluorocarboxylic acid, and water are brought together to form a reaction mass. Water is not necessary for the reaction. However, in a plant, it is possible to recycle either methyl trifluoroacetate or trifluoroacetic acid. If methyl trifluoroacetate is recycled, water is needed for the in situ hydrolysis. The most cost-effective way of recycling trifluoro acetic acid is to return this as trifluoroacetic acid/water azeotrope. The azeotrope is produced when hydrolyzing the ester. In either case, there is water in the reaction. Generally, the mixture is pressurized.
- reaction medium is heated and then held for a designated period of time during which the reaction occurs.
- the mixture is allowed to cool, after which it is washed with water. Wash water and unreacted acid are then separated from the mixture, yielding the LMW PTMEG Ester which is converted to LMW PTMEG in Reaction 2 of the process.
- the number-average molecular weight of the HMW PTMEG in Reaction 1 may range from 1000 to 25,000 and preferably from 1000 to 15,000, the most preferred being between 3000 and 10,000.
- the acid in Reaction 1 is a perfluoroalkylcarboxylic acid (RfA), such as trifluoroacetic acid (TFA), pentafluoropropionic acid, or heptafluorobutanoic acid, while the preferred reagent is TFA.
- RfA perfluoroalkylcarboxylic acid
- TFA trifluoroacetic acid
- Enough RfA should be added so that the weight ratio of RfA to PTMEG is 0.05 to 1.50 on a basis of 100% acid, the preferred ratio being in the range of 0.15 to 1.0.
- the most preferred weight ratio lies between 0.2 and 0.7.
- the mole ratio of the RfA .Iadd.to PTMEG .Iaddend. will always be from at least 2 to 20 .[.times greater than the starting number average molecular weight of the PTMEG, starting number average molecular weight of the PTMEG, and this.]. .Iadd.. This .Iaddend.ratio will depend greatly on the final number average molecular weight desired for the product PTMEG. Basically, the bigger the reduction .[.is.]. .Iadd.in .Iaddend.molecular weight desired the more RfA is required.
- the reaction mixture is heated to a temperature in the range of 100° to 250° C., preferably 120°to 200° C., while the most preferred mode calls for temperatures between 130° and 180° C.
- the pressure at which the reaction is conducted has not been found to significantly affect the results obtained.
- the actual pressure in the reactor will be the saturation pressure of the RfA at the given reaction temperature.
- the mixture should be maintained at those conditions for a period of 0.1 to 8.0 hours and preferable from 0.5 to 4.0 hours.
- the most preferred duration of reaction is in the range of 0.5 to 3.0 hours.
- the LMW PTMEG Ester can be converted to LMW PTMEG by a process such as that described by Pruckmayr in U.S. Pat. No. 4,230,892.
- the LMW PTMEG Ester can be converted to LMW PTMEG via an alcoholysis reaction in which the LMW PTMEG Ester is reacted with an alkanol having 1 to 3 carbon atoms in the presence of an ester exchange catalyst.
- an alcoholysis reaction is performed in absence of water and generates as a by-product the perfluoroalkyl ester of the acid used in Reaction 1.
- the Alcoholysis reaction does not function in the presence of water. It can be illustrated by the following equation: ##STR2## wherein: Rf is a perfluoroalkyl group containing 1 to 3 carbon atoms;
- x is the number of oxytetramethylene repeating units of the HMW perfluoroalkylester or LMW PTMEG molecules; m represents the amount of methanol required to achieve complete methanolysis of the product PTMEG.
- the perfluoroalkyl .Iadd.carboxylic .Iaddend. acid methyl ester .[.product.]. .Iadd.produced .Iaddend.as as a by-product in Reaction 2 can be converted by a staged equilibrium hydrolysis to RfA for use in Reaction 1 process. Although effective, such .[.as.]. hydrolysis adds to the expense of the process, because it adds another process step and requires additional equipment.
- An alternative to using a separate hydrolysis step to regenerate the acid is to use, in place of the acid in Reaction 1, a mixture of water and the perfluoroalkyl methyl ester produced in Reaction 2.
- the LMW PTMEG obtained as a product of the process of this invention has a number-average molecular weight between 250 and 3500.
- the preferred Mn is in the range of 650 to 2900 and the most preferred is between 650 and 2100.
- TFA trifluoroacetic acid
- Methanol is used in the alcoholysis reaction producing LMW PTMEG and methyl trifluoroacetate (MTFA).
- TFA may be used as such in Reaction 1, or it may be regenerated from the MTFA either by recycling the MTFA directly to Reaction 1 and allowing the TFA to form in situ or by a separate staged hydrolysis process.
- MTFA is used as the in situ source of TFA
- an excess of MTFA of 4 to 60, preferably 4 to 12 times that of the HMW PTMEG starting material on a molar basis is required depending on the final number average molecular weight desired.
- a mixture of poly(tetramethylene ether) diester starting material, catalyst and alkanol is first prepared. This can be done by simply mixing the three components together in a reactor, in any order.
- the catalyst is first slurried in the alkanol and this slurry is mixed with a solution of diester in alkanol. It is also important that all the three components are as dry as possible. Presence of water makes the catalyst alkaline and consequently could partially neutralize the diester. This decreases the recovery of the trifluoroacetic acid ester which is extremely expensive, and for this reason the presence of water is undesirable.
- the mixture is prepared so that it contains about 5-80%, preferably 20-60% (by total weight of the diester and alkanol) of diester.
- the catalyst is present in the mixture at a concentration of 0.02-3%, preferably 0.1-0.5% by weight of the diester, which is substantially less than the stoichiometric quantities.
- the catalyst used in this mixture is an oxide, hydroxide or alkoxide (in which the alkyl group contains 1-4 carbon atoms) of magnesium, calcium, sodium, barium or strontium. Sodium methoxide also is effective.
- the preferred catalyst is magnesium oxide because this particular catalyst leaves behind very little residue in the PTMEG.
- the alkanol in the mixture is one containing 1-4 carbon atoms.
- Methanol is the preferred alcohol in all the cases.
- the polymeric diester (PTMETA) starting material be neutral or nearly neutral i.e. have a pH value of about 7 before catalyst is added, for if the pH value is below about 7, the effect on the alcoholysis reaction will be impeded.
- the pH of the diester can be brought to neutral value or near neutral value by vacuum distilling the diester of PTMEG.
- the alcoholysis reaction mixture is then brought to its boiling point and held there, with stirring, while vapors of the alkyl trifiuoroacetate which form, are continuously withdrawn from the reaction zone.
- the boiling point of the mixture will be in the range of about 40°-150° C. If a temperature higher than this is required, the reaction can be run under a pressure of up to 100 atmospheres.
- the boiling and withdrawal of the alkyl trifluoroacetate is continued until the alcoholysis is substantially complete, i.e., until no more alkyl trifluoroacetate is detected in the vapor leaving the reaction vessel, as determined by gas chromatography.
- the process can be conducted batch wise or in a continuous fashion.
- the continuous mode is preferred for its efficiency.
- the process can be run in a single stage, it is preferably run in two or more stages, especially when run continuously, because this will give a higher degree of conversion.
- the continuous multi-stage process is run exactly as the one-stage process except that the contents of the first reactor are transferred sequentially to the others where alcoholysis is completed. Retention time in each reactor can be between 50 and 150 minutes. It may also be desirable to add the alkanol continuously to the secondary reactors in an amount equal to the amount of alkanol in the alkanol/alkyl trifluoroacetate withdrawn from the first reactor.
- the catalyst and such other insoluble materials as may be present are removed from the reaction mass by conventional techniques such as filtration, decantation or centrifugation. Ordinarily and preferably, the catalyst is filtered from the reaction mass and recycled to one of the reactors, but the reaction mass also can be withdrawn from the reactor through a filter which holds back the catalyst and other insoluble and keeps them in the reactor.
- the preferred catalyst is magnesium oxide or the hydroxide.
- the primary reason for this is that the magnesium salt of trifiuoroacetic acid is practically insoluble in PTMEG and therefore the finished product PTMEG is virtually free of the magnesium radical.
- the calcium salt of trifiuoroacetic acid is soluble in PTMEG and therefore a substantial portion of the calcium salt is left behind in the product. If calcium oxide or hydroxide was used as the catalyst, the PTMEG product has to be washed with water to make it calcium-free. This is an additional step in the unit operation which is not preferred.
- the PTMEG product of this process can be put to any conventional use such as the preparation of polyester or polyurethanes.
- This example demonstrates the use of TFA in reducing the molecular weight of PTMEG.
- a mixture containing 20 grams (0.175 gm. mol) of trifluoroacetic acid, 30 grams of water, and 50 grams (0.0244 gm. mol) of PTMEG with a number-average molecular weight of 2048, is placed in a pressure-bomb. At room temperature, nitrogen is sparged through the dip tube for about 15 minutes to displace any dissolved oxygen present in the mixture. The bomb is closed, and the vapor phase was pressurized to 30 psig (207 kPa) with nitrogen. The contents of the bomb are heated to 153° C.
- the pressure in the bomb is 125 psig (862 kPa).
- the contents of the bomb are maintained at 153° C. for 2 hours, they are cooled to 45° C. within less than 5 minutes.
- the mixture is then washed with water which, along with the unreacted acid, is removed by distillation at 125° C., using sparged nitrogen to facilitate the separation.
- Approximately 52.1 grams of the bis-trifluoroacetate of PTMEG are recovered.
- the bis-trifluoroacetate of PTMEG is converted to PTMEG by hydrolysis.
- 20 grams (0.0144 mol) of the ester is mixed with 100 grams (5.56 mols) of water, and the mixture is heated to 155° C.
- the material is cooled and the light phase comaining about 17 grams of PTMEG was dried at 125° C. with sparged nitrogen.
- the number average molecular weight of the hydrolyzed material is 1180 as determined by gel permeation chromatography.
- This example reports the use of MTFA used in situ as a source of TFA for the reduction of molecular weight of PTMEG.
- a mixture containing 49.48 grams (0.387 mol) of methyl trifluoroacetate, 26.43 grams (1.468 mol) of water, and 44.9 grams (0.0067 gm. mol) of PTMEG with a number-average molecular weight of 6750 is placed in a pressure bomb and heated to 155° C. over 1.5 hours during which the pressure in the bomb reached 150 psig (1034 kPa). After the contents of the bomb are cooled, volatile components including methyl trifluoroacetate, trifluoroacetic acid, and methanol are stripped from the mixture. Approximately 52.1 grams of the bis-trifluoroacetate of PTMEG is recovered. This material was hydrolyzed as in Example 1 to yield 42.3 g of PTMEG with a number average molecular weight of 1028.
- Examples 3 through 6 are conducted in the same manner as that used in Example 2. Pertinent data and results are reported below. Data from Example 2 are included for comparison.
- the product is then dried for 1 hours at 100° C. in a vacuum of 1 mm mercury. Filter aid is added and the product is filtered to remove insoluable material.
- the resulting PTMEG product (number average molecular weight of 855) contained less than 1 ppm magnesium as determined by atomic absorption.
- a 30 gram of the diester of PTMEG (number average molecular weight of 1140) is dissolved in 60 grams of methanol. After addition of 1 gram of MgO, the mixture is heated to 65° C. for about 3 hours with stirring while vapors from the reaction pot are condensed in a refrigerant-cooled glass vessel.
- the product is then dried at 120° C. and under vacuum. Filter aid, 0.3 gram is added and the product is filtered to remove insoluble material.
- the resulting PTMEG material (number average molecular weight of 991 ) is found to be virtually free of carbonyl esters as indicted by an infrared spectroscopic analysis.
- a 30 gram diester of PTMEG is dissolved in 70 grams of methanol. After the addition of 1 gram of calcium oxide, the mixture is heated to about 65° C. for about 3 hours with stirring while vapors from the reaction flask are condensed in a refrigerant-cooled glass vessel. The methyl trifluoroacetate collected corresponded to a conversion of 97%.
- the product is then dried at 120° C. under vacuum. Filter aid, 0.3 gram are added and the product filtered to remove insoluble material.
- the clear transparent PTMEG contains about 1.9% as, the calcium content was analyzed to be in excess of 10,000 ppm. The PTMEG had an orange color which comes from dissolved calcium trifluoroacetate.
Abstract
Description
TABLE 1 ______________________________________ Experimental Data for Examples 3-6 Reagents PTMEG Time Hold Max Grams MTFA H.sub.2 O Temp, Press, Ex. Hours Grams Grams °C. PSIG ______________________________________ 3 70.1 44.9 71.3 155 135 4 50.2 20.2 30.2 155 125 2 5 50.7 41.1 33.8 155 135 2 6 51.0 30.7 20.0 155 135 2 ______________________________________ Example Initial Mn PTMEG Final Mn PTMEG ______________________________________ 3 1982 1504 4 2072 1547 5 2072 1111 6 2072 1548 ______________________________________
Claims (22)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/263,842 USRE35360E (en) | 1992-03-10 | 1994-06-22 | Reduction of molecular weight of poly(tetramethylene ether) glycol |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/847,643 US5180857A (en) | 1992-03-10 | 1992-03-10 | Reduction of molecular weight of poly(tetramethylene ether) glycol |
US08/263,842 USRE35360E (en) | 1992-03-10 | 1994-06-22 | Reduction of molecular weight of poly(tetramethylene ether) glycol |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/847,643 Reissue US5180857A (en) | 1992-03-10 | 1992-03-10 | Reduction of molecular weight of poly(tetramethylene ether) glycol |
Publications (1)
Publication Number | Publication Date |
---|---|
USRE35360E true USRE35360E (en) | 1996-10-22 |
Family
ID=25301133
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/847,643 Ceased US5180857A (en) | 1992-03-10 | 1992-03-10 | Reduction of molecular weight of poly(tetramethylene ether) glycol |
US08/263,842 Expired - Lifetime USRE35360E (en) | 1992-03-10 | 1994-06-22 | Reduction of molecular weight of poly(tetramethylene ether) glycol |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/847,643 Ceased US5180857A (en) | 1992-03-10 | 1992-03-10 | Reduction of molecular weight of poly(tetramethylene ether) glycol |
Country Status (4)
Country | Link |
---|---|
US (2) | US5180857A (en) |
JP (1) | JPH07504697A (en) |
DE (2) | DE4391060C2 (en) |
WO (1) | WO1993018084A1 (en) |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3629325A (en) * | 1969-02-28 | 1971-12-21 | Jefferson Chem Co Inc | Cleaving poly(alkylene oxides) with acid anhydrides |
US3925484A (en) * | 1973-11-08 | 1975-12-09 | Du Pont | Process for making polytetramethylene ether glycol having a narrow molecular weight distribution |
US4120903A (en) * | 1977-03-30 | 1978-10-17 | E. I. Du Pont De Nemours And Company | Method for preparing poly(tetramethylene ether) glycol |
US4163115A (en) * | 1976-03-31 | 1979-07-31 | E. I. Du Pont De Nemours And Company | Preparation of esters of poly-(tetramethylene ether) glycol |
US4584414A (en) * | 1984-12-21 | 1986-04-22 | E. I. Du Pont De Nemours And Company | Process for preparing improved poly(tetramethylene ether) glycol by alcoholysis |
EP0433822A1 (en) * | 1989-12-19 | 1991-06-26 | BASF Aktiengesellschaft | Esters containing fluorocarbon groups bound to oxypropylenealkyl ether groups, emulsions containing these esters and their application in the production of cellular plastics by the polyisocyanate-polyaddition process |
EP0457129A2 (en) * | 1990-05-15 | 1991-11-21 | Miles Inc. | Process for the preparation of amine-terminated compounds |
-
1992
- 1992-03-10 US US07/847,643 patent/US5180857A/en not_active Ceased
-
1993
- 1993-03-10 DE DE4391060A patent/DE4391060C2/en not_active Expired - Lifetime
- 1993-03-10 WO PCT/US1993/002212 patent/WO1993018084A1/en active Application Filing
- 1993-03-10 DE DE4391060T patent/DE4391060T1/en active Pending
- 1993-03-10 JP JP5516002A patent/JPH07504697A/en active Pending
-
1994
- 1994-06-22 US US08/263,842 patent/USRE35360E/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3629325A (en) * | 1969-02-28 | 1971-12-21 | Jefferson Chem Co Inc | Cleaving poly(alkylene oxides) with acid anhydrides |
US3925484A (en) * | 1973-11-08 | 1975-12-09 | Du Pont | Process for making polytetramethylene ether glycol having a narrow molecular weight distribution |
US4163115A (en) * | 1976-03-31 | 1979-07-31 | E. I. Du Pont De Nemours And Company | Preparation of esters of poly-(tetramethylene ether) glycol |
US4120903A (en) * | 1977-03-30 | 1978-10-17 | E. I. Du Pont De Nemours And Company | Method for preparing poly(tetramethylene ether) glycol |
US4584414A (en) * | 1984-12-21 | 1986-04-22 | E. I. Du Pont De Nemours And Company | Process for preparing improved poly(tetramethylene ether) glycol by alcoholysis |
EP0433822A1 (en) * | 1989-12-19 | 1991-06-26 | BASF Aktiengesellschaft | Esters containing fluorocarbon groups bound to oxypropylenealkyl ether groups, emulsions containing these esters and their application in the production of cellular plastics by the polyisocyanate-polyaddition process |
US5126379A (en) * | 1989-12-19 | 1992-06-30 | Basf Aktiengesellschaft | Esters containing bonded fluorocarbon and oxypropylenealkylether groups, emulsions containing these esters and their use for the preparation of cellular plastics by polyisocyanate polyaddition |
EP0457129A2 (en) * | 1990-05-15 | 1991-11-21 | Miles Inc. | Process for the preparation of amine-terminated compounds |
Also Published As
Publication number | Publication date |
---|---|
WO1993018084A1 (en) | 1993-09-16 |
DE4391060C2 (en) | 2003-05-08 |
US5180857A (en) | 1993-01-19 |
DE4391060T1 (en) | 1995-02-23 |
JPH07504697A (en) | 1995-05-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0723951A1 (en) | Process to prepare bis (2-hydroxyethyl) terephthalate | |
US4460796A (en) | Purification of polytetramethylene ether-glycols | |
US5364973A (en) | Productive process for making conventional and low-unsaturation polyether polyols | |
KR102298521B1 (en) | Recovery method for direct polyol from polyethylene terephthalate wastes | |
US5852218A (en) | Alkanolysis of polyether polyol esters by reactive distillation | |
JP2558165B2 (en) | Process for producing high molecular weight polyalkylene oxide having unsaturated end groups | |
JP2893134B2 (en) | Method for producing polycarbonate having terminal hydroxyl group | |
JPH02247220A (en) | Isobutylene oxide polyol | |
US4584414A (en) | Process for preparing improved poly(tetramethylene ether) glycol by alcoholysis | |
USRE35360E (en) | Reduction of molecular weight of poly(tetramethylene ether) glycol | |
CN103224621B (en) | The alcoholysis method improved and device | |
KR100449304B1 (en) | Improved Method for Recovering Diacetate Esters of Polytetramethylene Ethers | |
CA1213902A (en) | Process of manufacturing diaryl esters of dicarboxylic acids | |
GB1575529A (en) | Polytetramethylene ether glycol esters | |
CN114163626A (en) | Polymerization catalyst, preparation method thereof and application of polymerization catalyst in preparation of poly (butylene succinate) | |
EP0611746A1 (en) | Hydroxy ethyl bibenzoate | |
JP3270574B2 (en) | Method for producing polyether polyol | |
EP0213800B2 (en) | Monomer Production | |
JP3396275B2 (en) | Block copolyether via oxonium coupling of poly (tetramethylene ether) glycol | |
US6569981B1 (en) | Crystallizing polyether polyols, a method for producing them and use of the same | |
JP2876243B2 (en) | Method for producing polyalkylene glycol polycarbonate | |
JPH02284918A (en) | Production of aliphatic polycarbonate diol | |
KR940007319B1 (en) | Process for preparation of polyester | |
EP0342862A2 (en) | A process for reducing fluoride levels in poly (tetramethylene ether)glycol | |
JPH09110980A (en) | Production of trifluoropropylene oxide polymer |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: INVISTA NORTH AMERICA S.A.R.L., DELAWARE Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:E. I. DU PONT DE NEMOURS AND COMPANY;REEL/FRAME:015286/0708 Effective date: 20040430 |
|
AS | Assignment |
Owner name: JPMORGAN CHASE BANK, N.A., TEXAS Free format text: SECURITY INTEREST;ASSIGNOR:INVISTA NORTH AMERICA S.A.R.L. F/K/A ARTEVA NORTH AMERICA S.A.R.;REEL/FRAME:015592/0824 Effective date: 20040430 |
|
AS | Assignment |
Owner name: DEUTSCHE BANK AG NEW YORK BRANCH, AS COLLATERAL AG Free format text: SECURITY AGREEMENT;ASSIGNOR:INVISTA NORTH AMERICA S.A.R.L.;REEL/FRAME:022416/0849 Effective date: 20090206 Owner name: INVISTA NORTH AMERICA S.A.R.L. (F/K/A ARTEVA NORTH Free format text: RELEASE OF U.S. PATENT SECURITY INTEREST;ASSIGNOR:JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT AND COLLATERAL AGENT (F/K/A JPMORGAN CHASE BANK);REEL/FRAME:022427/0001 Effective date: 20090206 |
|
AS | Assignment |
Owner name: INVISTA NORTH AMERICA S.A.R.L., NORTH CAROLINA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:DEUTSCHE BANK AG NEW YORK BRANCH;REEL/FRAME:027211/0298 Effective date: 20111110 |