ChemicalBook > CAS DataBase List > Tetrahydrofuran

Tetrahydrofuran

Product Name
Tetrahydrofuran
CAS No.
109-99-9
Chemical Name
Tetrahydrofuran
Synonyms
THF;Oxolane;PTMEG 2000;PTHF;Butylene oxide;Tetrahydrofurane;oxolan;PTMEG 1000;1,4-Epoxybutane;TETRAMETHYLENE ETHER GLYCOL 2000 POLYMER
CBNumber
CB6852795
Molecular Formula
C4H8O
Formula Weight
72.11
MOL File
109-99-9.mol
More
Less

Tetrahydrofuran Property

Melting point:
-108°C
Boiling point:
66 °C
Density 
0.887 g/mL at 20 °C
vapor density 
2.5 (vs air)
vapor pressure 
<0.01 mm Hg ( 25 °C)
refractive index 
n20/D 1.465
Flash point:
>230 °F
storage temp. 
Store at +5°C to +30°C.
solubility 
water: soluble
form 
Liquid
Specific Gravity
0.89
color 
<10(APHA)
Relative polarity
0.207
PH
7-8 (200g/l, H2O, 20℃)
Odor
Ethereal, detectable at 2 to 50 ppm
PH Range
7
explosive limit
1.5-12.4%(V)
Water Solubility 
miscible
FreezingPoint 
-108℃
Sensitive 
Air Sensitive & Hygroscopic
λmax
λ: 245 nm Amax: ≤0.26
λ: 275 nm Amax: ≤0.046
λ: 315 μm Amax: ≤0.0044
Merck 
14,9211
BRN 
102391
Henry's Law Constant
1.54 (static headspace-GC, Welke et al., 1998)
Exposure limits
TLV-TWA 200 ppm (590 mg/m3) (ACGIH, MSHA, and OSHA); STEL 250 ppm (ACGIH); IDLH 20,000 ppm (NIOSH).
Dielectric constant
7.5800000000000001
Dielectric constant
11.6(-70℃)
Stability:
Stable. Incompatible with halogens, strong oxidizing agents, strong reducing agents, strong bases, oxygen. May generate explosive peroxides in storage if in contact with air. Highly flammable. Store at room temperature under nitrogen. Hazardous polymerisation may occur. Light sensitive. May contain 2,6-di-tertbutyl-4-methylphenol (BHT) as a s
InChIKey
WYURNTSHIVDZCO-UHFFFAOYSA-N
LogP
0.45 at 25℃
CAS DataBase Reference
109-99-9(CAS DataBase Reference)
NIST Chemistry Reference
Furan, tetrahydro-(109-99-9)
IARC
2B (Vol. 119) 2019
EPA Substance Registry System
Tetrahydrofuran (109-99-9)
More
Less

Safety

Hazard Codes 
Xi,F,Xn
Risk Statements 
36/37/38-36/37-19-11-40
Safety Statements 
26-36-33-29-16-46-37-13
RIDADR 
UN 2924 3/PG 2
OEB
A
OEL
TWA: 200 ppm (590 mg/m3), STEL: 250 ppm (735 mg/m3)
WGK Germany 
1
RTECS 
MD0916000
3-10-23
Autoignition Temperature
610 °F
TSCA 
Yes
HazardClass 
3
PackingGroup 
II
HS Code 
29321100
Hazardous Substances Data
109-99-9(Hazardous Substances Data)
Toxicity
LD50 oral (rat) 2880 mg/kg
LC50 inhal (rat) 21,000 ppm (3 h)
PEL (OSHA) 200 ppm (590 mg/m3)
TLV-TWA (ACGIH) 200 ppm (590 mg/m3)
STEL (ACGIH) 250 ppm (737 mg/m3)
IDLA
2,000 ppm [10% LEL]
More
Less

Hazard and Precautionary Statements (GHS)

Symbol(GHS)
Signal word
Danger
Hazard statements

H225Highly Flammable liquid and vapour

H302Harmful if swallowed

H319Causes serious eye irritation

H335May cause respiratory irritation

H336May cause drowsiness or dizziness

H351Suspected of causing cancer

Precautionary statements

P201Obtain special instructions before use.

P202Do not handle until all safety precautions have been read and understood.

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P308+P313IF exposed or concerned: Get medical advice/attention.

More
Less

N-Bromosuccinimide Price

Sigma-Aldrich
Product number
TX0282
Product name
Tetrahydrofuran Non-UV
Purity
OmniSolv?
Packaging
1L
Price
$156
Updated
2024/03/01
Sigma-Aldrich
Product number
TX0280
Product name
Tetrahydrofuran
Purity
Meets ACS Specifications GR ACS
Packaging
500mL
Price
$168
Updated
2024/03/01
Sigma-Aldrich
Product number
TX0282
Product name
Tetrahydrofuran Non-UV
Purity
OmniSolv?
Packaging
4L
Price
$480
Updated
2024/03/01
Sigma-Aldrich
Product number
TX0280
Product name
Tetrahydrofuran
Purity
Meets ACS Specifications GR ACS
Packaging
4L
Price
$695
Updated
2024/03/01
Sigma-Aldrich
Product number
TX0282
Product name
Tetrahydrofuran Non-UV
Purity
OmniSolv?
Packaging
18.9L
Price
$2850
Updated
2024/03/01
More
Less

Tetrahydrofuran Chemical Properties,Usage,Production

Description

Tetrahydrofuran (THF) is a colorless, volatile liquid with an ethereal or acetonelike smell and is miscible in water and most organic solvents.It is highly flammable and may thermally decompose to carbon monoxide and carbon dioxide. Prolonged storage in contact with air and in the absence of an antioxidant may cause THF to decompose into explosive peroxides.

Tetrahydrofuran is used in the manufacture of polymers as well as agricultural, pharmaceutical, and commodity chemicals. Manufacturing activities commonly occur in closed systems or under engineering controls that limit worker exposure and release to the environment. THF is also used as a solvent (e.g., pipe fitting) that may result in more significant exposures when used in confined spaces without sufficient ventilation. Although THF is naturally present in coffee aroma, floured chickpeas, and cooked chicken, natural exposures are not anticipated to pose a significant hazard.

Description

THF (Tetrahydrofuran) is a stable compound with relatively low boiling point and excellent solvency. It is widely-used for dissolution and reaction of various substances. Also it is used as a starting material for the synthesis of poly(tetramethylene ether) glycol (PTMG), etc. Since 1982, Mitsubishi Chemical's Yokkaichi plant has produced high-purity, high-quality THF from butadiene using our proprietary technology. CAS: No. 109-99-9 (T) EINECS: No. 203-726-8 Japan, Chemical Substances Control Law: METI-No. 5-53 Japan, Industrial Safety and Health Law: No. 5-53, ID No. 367 (SDS required) Japan, Poisonous and Deleterious Substances Control Law: Not applicable. Japan, Fire Services Law: Hazardous Material Class 4 Petroleums No.1 (water-soluble liquid). Hazardous Rank II U.N. Class: 3  U.N. No.: UN2056

Chemical Properties

Tetrahydrofuran (THF) is an industrial solvent widely recognized for its unique combination of useful properties. DuPont THF is better than 99.9% pure with a small (0.025-0.040 wt % ) amount of butylated hydroxytoluene (BHT, 4-methyl-2,6-di-tertbutyl phenol) added as an antioxidant. Tetrahydrofuran is a cycloaliphatic ether and is not "photochemically reactive" as defined in Section k of Los Angeles County's Rule 66 (equivalent to Rule 442 of the Southern California Air Pollution Control District). THF has an ethereal odor. The Odor Threshold is listed @ 3.8 (3M), 20-50ppm, and 31ppm. It is also a common laboratory reagent and an intermediate in chemical syntheses of consumer and industrial products such as nutritionals, pharmaceuticals, and insecticides (HSDB, 2011).

Physical properties

Tetrahydrofuran is a clear, colourless liquid with a strong ether-like odour. Odor threshold concentration is 2 ppm (quoted, Amoore and Hautala, 1983). It is highly flammable. Contact of tetrahydrofuran with strong oxidising agents may cause explosions. Tetrahydrofuran may polymerise in the presence of cationic initiators. Contact with lithium–aluminium hydride, with other lithium–aluminium alloys, or with sodium or potassium hydroxide can be hazardous.

Uses

Solvent for high polymers, especially polyvinyl chloride. As reaction medium for Grignard and metal hydride reactions. In the synthesis of butyrolactone, succinic acid, 1,4-butanediol diacetate. Solvent in histological techniques. May be used under Federal Food, Drug & Cosmetic Act for fabrication of articles for packaging, transporting, or storing of foods if residual amount does not exceed 1.5% of the film: Fed. Regist. 27, 3919 (Apr. 25, 1962).

Uses

Butylene oxide is used as a fumigant and inadmixture with other compounds. It is usedto stabilize fuel with respect to color andsludge formation.

Uses

Tetrahydrofuran is used primarily (80%) to make polytetramethylene ether glycol, the base polymer used primarily in the manufacture of elastomeric fibers (e.g., spandex) as well as polyurethane and polyester elastomers (e.g., artificial leather, skateboard wheels). The remainder (20%) is used in solvent applications (e.g., pipe cements, adhesives, printing inks, and magnetic tape) and as a reaction solvent in chemical and pharmaceutical syntheses.

Uses

Tetrahydrofuran is used as a solvent forresins, vinyls, and high polymers; as a Grignardreaction medium for organometallic,and metal hydride reactions; and in the synthesisof succinic acid and butyrolactone.

Definition

ChEBI: A cyclic ether that is butane in which one hydrogen from each methyl group is substituted by an oxygen.

General Description

A clear colorless liquid with an ethereal odor. Less dense than water.Flash point 6°F. Vapors are heavier than air.

Air & Water Reactions

Highly flammable. Oxidizes readily in air to form unstable peroxides that may explode spontaneously [Bretherick, 1979 p.151-154, 164]. Soluble in water.

Reactivity Profile

Tetrahydrofuran reacts violently with oxidizing agents leading to fires and explosions [Handling Chemicals Safely 1980. p. 891]. Subject to peroxidation in the air. Peroxides or their products react exothermically with lithium aluminum hydride [MCA Guide for Safety 1973]. Thus, use as a solvent for lithium aluminum hydride has led to fires. Using potassium hydroxide or sodium hydroxide to dry impure Tetrahydrofuran that contains peroxides has resulted in explosions. A violent explosion occurred during the preparation of sodium aluminum hydride from sodium and aluminum in a medium of Tetrahydrofuran [Chem. Eng. News 39(40):57. 1961]. THF forms explosive products with 2-aminophenol [Lewis 3227].

Health Hazard

The toxicity of tetrahydrofuran is of loworder in animals and humans. The targetorgans are primarily the respiratory systemand central nervous system. It is an irritantto the upper respiratory tract and eyes.At high concentrations it exhibits anestheticproperties similar to those of many loweraliphatic ethers. Exposure to concentrationsabove 25,000 ppm in air can cause anesthesiain humans. Other effects noted were strongrespiratory stimulation and fall in bloodpressure (ACGIH 1986). Kidney and liverinjuries occurred in experimental animalsexposed to 3000 ppm for 8 hours/day for20 days (Lehman and Flury 1943). Inhalationof high concentrations of vapors or ingestionof the liquid also causes nausea, vomiting,and severe headache. The acute oraltoxicity is low; the LD50 value in rats is in therange of 2800 mg/kg. The inhalation LC50value in rats is 21,000 ppm/3 h.

Flammability and Explosibility

THF is extremely flammable (NFPA rating = 3), and its vapor can travel a considerable distance to an ignition source and "flash back." A 5% solution of THF in water is flammable. THF vapor forms explosive mixtures with air at concentrations of 2 to 12% (by volume). Carbon dioxide or dry chemical extinguishers should be used for THF fires.
THF can form shock- and heat-sensitive peroxides, which may explode on concentration by distillation or evaporation. Always test samples of THF for the presence of peroxides before distilling or allowing to evaporate. THF should never be distilled to dryness.

Chemical Reactivity

Reactivity with Water No reaction; Reactivity with Common Materials: No data; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: May occur when the product is in contact with strong acids and bases; Inhibitor of Polymerization: No data.

Industrial uses

Tetrahydrofuran (THF), the saturated derivative of furan, when used as a solvent for high molecular weight polyvinyl chloride (PVC), vinyl chloride copolymers, and polyvinylidene chloride copolymers at ambient temperatures yields solutions of high solids content. Blends of THF and methyl ethyl ketone are often used for increased solvency in certain polymer compositions. Applications for THF polymer solutions include PVC top coatings of automotive upholstery, audio tape coatings of polyurethane/metal oxides on polyester tape, polyurethane coatings for fabric finishes, water-vapor barrier film coatings of PVC, and polyvinylidene chloride copolymers onto cellophane film. Tetrahydrofuran is an excellent solvent for many inks used for printing on PVC film and on PVC plastic articles. Polyvinyl chloride pipe welding cements are made by dissolving the resin in THF solvent. Other adhesive applications include cements for leather, plastic sheeting, and for molded plastic assemblies. Other uses of THF are as a chemical intermediate and as a complexing solvent for various inorganic, organometallic, and organic compounds. These THF complexes are important as Grignard reagents, catalysts for organic reactions, and in stereo-specific polymerizations. Tetrahydrofuran is the solvent of choice in many pharmaceutical reactions and applications. The excellent solvency of THF makes this solvent ideal for solvent cleaning of polymer manufacturing and processing equipment.

Safety Profile

Moderately toxic by ingestion and intraperitoneal routes. Mildly toxic by inhalation. Human systemic effects by inhalation: general anesthesia. Mutation data reported. Irritant to eyes and mucous membranes. Narcotic in high concentrations. Reported as causing injury to liver and kidneys. Flammable liquid. A very dangerous fire hazard when exposed to heat, flames, oxidizers. Explosive in the form of vapor when exposed to heat or flame. In common with ethers, unstabilized tetrahydrofuran forms thermally explosive peroxides on exposure to air. Stored THF must always be tested for peroxide prior to distdlation. Peroxides can be removed by treatment with strong ferrous sulfate solution made slightly acidic with sodium bisulfate. Caustic alkalies deplete the inhibitor in THF and may subsequently cause an explosive reaction. Explosive reaction with KOH, NaAlH2, NaOH, sodium tetrahydroaluminate. Reacts with 2-aminophenol + potassium dioxide to form an explosive product. Reacts with lithium tetrahydroaluminate or borane to form explosive hydrogen gas. Violent reaction with metal halides (e.g., hafnium tetrachloride, titanium tetrachloride, zirconium tetrachloride). Vigorous reaction with bromine, calcium hydride + heat. Can react with oxidizing materials. To fight fire, use foam, dry chemical, COa. When heated to decomposition it emits acrid smoke and irritating fumes. See also 2TETRAHYDROFURYL HYDROPEROXIDE

Potential Exposure

The primary use of tetrahydrofuran is as a solvent to dissolve synthetic resins, particularly polyvinyl chloride and vinylidene chloride copolymers. It is also used to cast polyvinyl chloride films, to coat substrates with vinyl and vinylidene chloride; and to solubilize adhesives based on or containing polyvinyl chloride resins. A second large market for THF is as an electrolytic solvent in the Grignard reaction-based production of tetramethyl lead. THF is used as an intermediate in the production of polytetramethylene glycol.

Carcinogenicity

THF showed little evidence of mutagenic activity in a variety of in vitro and in vivo assays.

Source

Leaches from PVC cement used to join tubing (Wang and Bricker, 1979)

storage

THF should be used only in areas free of ignition sources, and quantities greater than 1 liter should be stored in tightly sealed metal containers in areas separate from oxidizers. Containers of THF should be dated when opened and tested periodically for the presence of peroxides.

Shipping

UN2056 Tetrahydrofuran, Hazard Class: 3; Labels: 3-Flammable liquid.

Purification Methods

It is obtained commercially by catalytic hydrogenation of furan from pentosan-containing agricultural residues. It was purified by refluxing with, and distilling from LiAlH4 which removes water, peroxides, inhibitors and other impurities [Jaeger et al. J Am Chem Soc 101 717 1979]. Peroxides can also be removed by passage through a column of activated alumina, or by treatment with aqueous ferrous sulfate and sodium bisulfate, followed by solid KOH. In both cases, the solvent is then dried and fractionally distilled from sodium. Lithium wire or vigorously stirred molten potassium have also been used for this purpose. CaH2 has also been used as a drying agent. Several methods are available for obtaining the solvent almost anhydrous. Ware [J Am Chem Soc 83 1296 1961] dried it vigorously with sodium-potassium alloy until a characteristic blue colour was evident in the solvent at Dry-ice/cellosolve temperatures. The solvent is kept in contact with the alloy until distilled for use. Worsfold and Bywater [J Chem Soc 5234 1960], after refluxing and distilling from P2O5 and KOH, in turn, refluxed the solvent with sodium-potassium alloy and fluorenone until the green colour of the disodium salt of fluorenone was well established. [Alternatively, instead of fluorenone, benzophenone, which forms a blue ketyl, can be used.] The tetrahydrofuran was then fractionally distilled, degassed and stored above CaH2. p-Cresol or hydroquinone inhibit peroxide formation. The method described by Coetzee and Chang [Pure Appl Chem 57 633 1985] for 1,4-dioxane also applies here. Distillations should always be done in the presence of a reducing agent, e.g. FeSO4. [Beilstein 17 H 10, 17 I 5, 17 II 15, 17 III/IV 24, 17/1 V 27.] It irritates the skin, eyes and mucous membranes, and the vapour should never be inhaled. It is HIGHLY FLAMMABLE, and the necessary precautions should be taken. Rapid purification: Purification as for diethyl ether.

Toxicity evaluation

The principal target organs in rodents receiving repeated exposures to THF are the central nervous system (CNS), kidney, and liver. The CNS effects caused by THF are thought to be mediated via the THF metabolites tetrahydro-2-furanone and 4-hydroxybutanoic acid. This is consistent with the CNS effects associated with these metabolites as well as the higher narcotic potency of THF in mice than in comparably exposed rats and the shorter half-life of THF in the presence of mouse versus rat hepatic microsomes. In contrast to the CNS effects, the male rat kidney tumors and female mouse liver tumors appear to be induced by the parent compound, not a metabolite. Lifetime exposures of rodents to tetrahydro-2-furanone, 4-hydroxybutanoic acid, and sodium succinate have not resulted in treatment-related carcinogenic effects, and a mechanistic study demonstrated that hepatocellular proliferation in female mice exposed to THF is actually enhanced by CYP450 inhibition, not decreased as one would predict if proliferation is mediated by a THF metabolite. The THF database has been reviewed against potential mode of action (MoA) candidates including direct DNA reactivity, cytotoxicity followed by regenerative cell proliferation, excessive accumulation of alpha 2u-globulin, exacerbation of rat chronic progressive nephropathy (CPN), and nuclear receptor (e.g., constitutive androstane receptor) activation leading to enzyme induction and enhanced cell proliferation. While the tumorigenic MoAs have not been identified, exacerbation of CPN (rat kidney) and nuclear receptor activation (mouse liver) are currently the more favored. BothMoAs are thought to involve nongenotoxic (i.e., threshold) events. CPN has no known counterpart in humans.

Incompatibilities

Forms thermally explosive peroxides in air on standing (in absence of inhibitors). Peroxides can be detonated by heating, friction, or impact. Reacts violently with strong oxidizers, strong bases and some metal halides. Attacks some forms of plastics, rubber and coatings.

Waste Disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. Concentrated waste containing peroxides-perforation of a container of the waste from a safe distance followed by open burning.

More
Less

Tetrahydrofuran Suppliers

Vital Trade Pty., Ltd.
Tel
--
Fax
--
Email
vitaltrade@vitaltrade.com
Country
Australia
ProdList
92
Advantage
58
Redox Pty Ltd.
Tel
--
Fax
--
Country
Australia
ProdList
380
Advantage
58
Ace Chemical Company
Tel
--
Fax
--
Email
acechem@senet.com.au
Country
Australia
ProdList
229
Advantage
58
More
Less

View Lastest Price from Tetrahydrofuran manufacturers

Hebei Weibang Biotechnology Co., Ltd
Product
Tetrahydrofuran 109-99-9
Price
US $10.00/KG
Min. Order
1KG
Purity
99%
Supply Ability
100 mt
Release date
2024-11-07
Hebei Chuanghai Biotechnology Co,.LTD
Product
Tetrahydrofuran 109-99-9
Price
US $80.00-20.00/KG
Min. Order
10KG
Purity
99.9%
Supply Ability
10000kg
Release date
2024-08-16
Shanghai Longyu Biotechnology Co., Ltd.
Product
Tetrahydrofuran 109-99-9
Price
US $1.00/g
Min. Order
1g
Purity
99
Supply Ability
20 tons
Release date
2021-12-06

109-99-9, TetrahydrofuranRelated Search:


  • TETRAMETHYLENE ETHER GLYCOL 2000 POLYMER
  • Tetrahydrofuran ,99.8% [Tetrahydrofuran,ACS/HPLC Certified]
  • Tetrahydrofuran, 99.6%, stabilized with BHT, for analysis ACS
  • Tetrahydrofuran, 99+%, stabilized with BHT, extra pure
  • Tetrahydrofuran, 99.9%, anhydrous, stabilized, extra pure
  • Tetrahydrofuran, 99.5+%, for spectroscopy
  • Tetrahydrofuran, 99.8%, unstabilized, for HPLC
  • Tetrahydrofuran, 99.85%, water <50 ppm, stabilized, extra dry
  • Tetrahydrofuran, anhydrous, stabilized, extra pure, 99.9%
  • Tetrahydrofuran, for spectroscopy, 99.5+%
  • Tetrahydrofuran, stabilized with BHT, extra pure, 99+%
  • Tetrahydrofuran, stabilized with BHT, for analysis ACS, 99.6%
  • Tetrahydrofuran, unstabilized, for HPLC, 99.8%
  • Tetrahydrofuran, water <50 ppm, stab., extra dry over mol. sieve, 99.5%
  • Tetrahydrofuran, water <50 ppm, stabilized, extra dry, 99.85%
  • TETRAHYDROFURAN DISTILLED IN GLASS
  • TETRAHYDROFURAN HALOGEN FREE
  • TETRAHYDROFURAN HPLC
  • TETRAHYDROFURAN REAGENT (ACS)
  • Furan, tetrahydro-
  • tetrahydrofuran, anhydrous
  • tetrahydrofuran, biograde
  • tetrahydrofuran, non-uv, hplc grade
  • tetrahydrofuran, spectrophotometric grade
  • tetrahydrofuran, uv, hplc grade
  • TETRAHYDROFURAN,OMNISOLV
  • TETRAHYDROFURAN,REAGENT,ACS(BULK
  • TETRAHYDROFURAN,TECHNICAL
  • PTHF
  • PTMEG 1800
  • PTMEG 1400
  • PTMEG 1000 S
  • PTMEG 1000
  • PTMEG 650 S
  • PTMEG 250
  • PTMEG 2000
  • TERATHANE(R) 1000 POLYETHER GLYCOL
  • TERATHANE(R) 1400 POLYETHER GLYCOL
  • TERATHANE(R) 1400
  • TERATHANE(TM) 2000 POLYETHER GLYCOL
  • TERATHANE(R) 650 POLYETHER GLYCOL
  • TERATHANE(R) 2900 POLYETHER GLYCOL
  • TERATHANE(R) 2000 POLYETHER GLYCOL
  • TERATHANE(TM) 650 POLYETHER GLYCOL
  • TERATHANE(TM) 2900 POLYETHER GLYCOL
  • POLYLETRAHYDROFURAN, LINEAR CHAIN POLYMER
  • POLY(TETRAMETHYLENE ETHER) GLYCOL
  • POLYTETRAMETHYLENE ETHER GLYCOL 1000 S
  • POLYTETRAMETHYLENE ETHER GLYCOL 1000
  • POLYTETRAHYDROFURAN, LINEAR-CHAIN POLYMER
  • POLYTETRAHYDROFURAN 650 S
  • POLYTETRAHYDROFURAN 250
  • POLYTETRAHYDROFURAN 2000
  • POLYTETRAHYDROFURAN 1800
  • POLYTETRAHYDROFURAN 1400
  • POLYTETRAHYDROFURAN 1000 S
  • POLYTETRAHYDROFURAN 1000
  • POLY (TETRAMETHYLENE OXIDE) 1,400