Polytetrahydrofuran

Structural formula
General
Surname	Polytetrahydrofuran
other names	PTHF; Polytetramethylene ether glycol (PTMEG); PolyTHF;
CAS number	25190-06-1
Monomer	Tetrahydrofuran
Molecular formula of the repeating unit	C 4 H 8 O
Molar mass of the repeating unit	72.11 g mol −1
Type of polymer	Thermoplastic
Brief description	white waxy solid
properties
Physical state	firmly
density	0.982 g / cm 3 (30 ° C)
Melting point	23-28 ° C
solubility	<10 g / l in water at 20 ° C
safety instructions
GHS labeling of hazardous substances average M n ~ 1,000; Caution
H and P phrases	H: 315-319-335
	P: 261-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Polytetrahydrofuran is produced from tetrahydrofuran by acid catalysis at 30 to 40 ° C. The chemical name for polytetrahydrofuran is polytetramethylene ether glycol (PTMEG)

Polytetrahydrofuran is a preliminary product for the synthesis of textile fibers (elastane, spandex), which are characterized by high elasticity. Polytetrahydrofuran forms the soft component here. In addition, you can z. B. also produce polyurethanes from polytetrahydrofuran.

Polytetrahydrofuran usually consists of a mixture of different oligomers / polymers with a defined mean molar mass . Polytetrahydrofuran is solid at room temperature and is therefore used at elevated temperatures, e.g. B. 60-70 ° C, stored, bottled and transported in liquid form.

A major manufacturer in Germany is BASF in Ludwigshafen (250,000 tons / year).

Manufacturing

The basic material for the production of PolyTHF is ethyne (acetylene), which u. a. can be obtained from natural gas. This is converted with formaldehyde to 2-butyne-1,4-diol and finally to 1,4-butanediol by hydrogenation . Tetrahydrofuran (THF) is obtained by acid-catalyzed cyclization of 1,4-butanediol .

PolyTHF can now be polymerized by acid catalysis, for example using boron trifluoride or other Lewis acids and water or an alcohol .

PolyTHF can be produced with different molar masses, which is represented by adding a number: PolyTHF 1000 has an average molar mass of around 1000 g · mol ⁻¹ .

use

PolyTHF is used in very different areas:

Textile industry

The textile industry uses PolyTHF to produce spandex and elastane fibers. It processes the spandex fibers together with cotton, polyamide or polyester fibers into fabrics from which, for example, stretch jeans, swimsuits, socks, underwear or functional sports clothing are made. Spandex fibers are primarily characterized by their high elasticity. They are also light, dimensionally stable and gentle on the skin.

Further areas of application

Thermoplastic polyurethane elastomers (TPU) are also made from polytetrahydrofuran. These are processed into flexible and abrasion-resistant hoses or cable sheathing, for example. Skateboard and inline skate wheels are also partly made of PolyTHF.

recycling

By heating polytetrahydrofuran in the presence of catalysts, the polymer can be depolymerized and the monomer tetrahydrofuran can be recovered by distillation. The product can be used for the synthesis of new polytetrahydrofuran (chemical recycling).

Individual evidence

↑ ^a ^b ^c ^d Data sheet PTHF 1000, stabilized with 2,6-di-tert-butyl-4-methylphenol (PDF) from Merck , accessed on January 19, 2011.
↑ ^a ^b Datasheet Poly (tetrahydrofuran) average M _n ~ 1,000 from Sigma-Aldrich , accessed on May 29, 2011 ( PDF ).
^ BASF Intermediates Division - PolyTHF .
↑ BASF SE: Expand your success on elastomers: PolyTHF. BASF SE, accessed on November 27, 2018 .
↑ S. Enthaler, A. Trautner: Iron-Catalyzed Ring-Closing Depolymerization of Poly (tetrahydrofuran) . In: ChemSusChem . tape 6 , no. 8 , August 1, 2013, ISSN 1864-564X , p. 1334-1336 , doi : 10.1002 / cssc.201300380 .
↑ S. Enthaler: Zinc (II) -triflate as catalyst precursor for ring-closing depolymerization of end-of-life polytetrahydrofuran to produce tetrahydrofuran . In: Journal of Applied Polymer Science . tape 131 , no. 2 , January 15, 2014, ISSN 1097-4628 , p. n / a – n / a , doi : 10.1002 / app.39791 .

[Merck-1] Data sheet PTHF 1000, stabilized with 2,6-di-tert-butyl-4-methylphenol (PDF) from Merck , accessed on January 19, 2011.

[Sigma-2] Datasheet Poly (tetrahydrofuran) average M _n ~ 1,000 from Sigma-Aldrich , accessed on May 29, 2011 ( PDF ).

[3] BASF Intermediates Division - PolyTHF .

[4] BASF SE: Expand your success on elastomers: PolyTHF. BASF SE, accessed on November 27, 2018 .

[5] S. Enthaler, A. Trautner: Iron-Catalyzed Ring-Closing Depolymerization of Poly (tetrahydrofuran) . In: ChemSusChem . tape 6 , no. 8 , August 1, 2013, ISSN 1864-564X , p. 1334-1336 , doi : 10.1002 / cssc.201300380 .

[6] S. Enthaler: Zinc (II) -triflate as catalyst precursor for ring-closing depolymerization of end-of-life polytetrahydrofuran to produce tetrahydrofuran . In: Journal of Applied Polymer Science . tape 131 , no. 2 , January 15, 2014, ISSN 1097-4628 , p. n / a – n / a , doi : 10.1002 / app.39791 .