Poly tetrahydrofuran

Several polymers were synthesized to initiate the development of this concept (30). In one case (single amino acid), poly(palmitoyl-hydroxypro-line [(Pal-Hpr)-ester] was obtained by melt transesterification of Af-Pal-Hpr-Me in the presence of aluminum isopropoxide as catalyst. In a second case (dipeptide), the tyrosine (Tyr) dipeptide carbobenzyoxy-Tyr-Tyr-Hex was cyanylated at the tyrosine side chain hydroxyl groups, to yield car-bobenzoxy-Tyr-Tyr-Hex-dicyanate. By solution polymerization of equimolar quantities of carbobenzoxy-Tyr-Tyr-Hex and carbobenzoxy-Tyr-Tyr-Hex-dicyanate in tetrahydrofuran, poly(carbobenzoxy-Tyr-Tyr-Hex-iminocarbonate) (polyCTTH) was obtained with Mn = 11,500 and Mw = 19,500. 

Tetrahydrofuran Poly(tetrafluor ethylene-co vinylidenfluorid-co-propylene) (PFE-VFP) poly(4-vinyl phenol) (PVPh) poly(vinyl chloride) (PVC)... 

Poly (ethylene glycol) or poly (ethylene oxide) Poly [(ethylene oxide)-ran-(propylene oxide)] PEO-poly [(/ )-3-hydroxybutyrate]-PEO Poly (8-caprolactone)-poly(tetrahydrofuran)-poly (e-caprolactone)... 

Poly(tetrahydrofuran), poly(caprolactone), and poly(propylene glycol) monobutyl ether (PPGBE) chains using toluene 2,4-diisocyanate as a linking agent (Labet et al. 2007)... 

Poly(tetrahydrofuran) Poly(butylene oxide) tetrahy-drofuran homopolymer, SRU THF polymer, SRU 251 90-06-1 Poly(oxy-1,4-butanediyl), a-hydro-(9-hydroxy- R (C4H 0) H20... 

POLYETHERS - TETRAHYDROFURAN AND OXETANE POLYTffiRS] (Vol 19) Poly[oxy(dimethylsilylene)] [9016-00-6]... 

Uses. The largest uses of butanediol are internal consumption in manufacture of tetrahydrofuran and butyrolactone (145). The largest merchant uses are for poly(butylene terephthalate) resins (see Polyesters,thermoplastic) and in polyurethanes, both as a chain extender and as an ingredient in a hydroxyl-terminated polyester used as a macroglycol. Butanediol is also used as a solvent, as a monomer for vadous condensation polymers, and as an intermediate in the manufacture of other chemicals. 

Tetrahydrofuran is polymerized to poly(tetramethylene glycol) with fuming sulfuric acid and potassium biduoride (29). 

Butanediol. 1,4-Butanediol [110-63-4] made from formaldehyde and acetylene, is a significant market for formaldehyde representing 11% of its demand (115). It is used to produce tetrahydrofuran (THF), which is used for polyurethane elastomers y-butyrolactone, which is used to make various pyrroHdinone derivatives poly(butylene terephthalate) (PBT), which is an engineering plastic and polyurethanes. Formaldehyde growth in the acetylenic chemicals market is threatened by alternative processes to produce 1,4-butanediol not requiring formaldehyde as a raw material (140) (see Acetylene-derived chemicals). 

The most important tetrahydrofuran polymers are the hydroxy-terrninated polymers, that is, the a,C0-poly(tetramethylene ether) glycols used commercially to manufacture polyurethanes and polyesters (see Urethane polymers Polyesters, thermoplastic). 

Properties have been determined for a series of block copolymers based on poly[3,3-bis(ethoxymethyl)oxetane] and poly [3,3-bis(methoxymethyl)oxetane]- (9-tetrahydrofuran. The block copolymers had properties suggestive of a thermoplastic elastomer (308). POX was a good main chain for a weU-developed smectic Hquid crystalline state when cyano- or fluorine-substituted biphenyls were used as mesogenic groups attached through a four-methylene spacer (309,310). Other side-chain Hquid crystalline polyoxetanes were observed with a spacer-separated azo moiety (311) and with laterally attached mesogenic groups (312). 

Polyether Polyols. Polyether polyols are addition products derived from cyclic ethers (Table 4). The alkylene oxide polymerisation is usually initiated by alkah hydroxides, especially potassium hydroxide. In the base-catalysed polymerisation of propylene oxide, some rearrangement occurs to give aHyl alcohol. Further reaction of aHyl alcohol with propylene oxide produces a monofunctional alcohol. Therefore, polyether polyols derived from propylene oxide are not truly diftmctional. By using sine hexacyano cobaltate as catalyst, a more diftmctional polyol is obtained (20). Olin has introduced the diftmctional polyether polyols under the trade name POLY-L. Trichlorobutylene oxide-derived polyether polyols are useful as reactive fire retardants. Poly(tetramethylene glycol) (PTMG) is produced in the acid-catalysed homopolymerisation of tetrahydrofuran. Copolymers derived from tetrahydrofuran and ethylene oxide are also produced. 

In the suspension polymerization of PVC, droplets of monomer 30—150 p.m in diameter are dispersed in water by agitation. A thin membrane is formed at the water—monomer interface by dispersants such as poly(vinyl alcohol) or methyl cellulose. This membrane, isolated by dissolving the PVC in tetrahydrofuran and measured at 0.01—0.02-p.m thick, has been found to be a graft copolymer of polyvinyl chloride and poly(vinyl alcohol) (4,5). Early in the polymerization, particles of PVC deposit onto the membrane from both the monomer and the water sides, forming a skin 0.5—5-p.m thick that can be observed on grains sectioned after polymerization (4,6). Primary particles, 1 p.m in diameter, deposit onto the membrane from the monomer side (Pig. 1), whereas water-phase polymer, 0.1 p.m in diameter, deposits onto the skin from the water side of the membrane (Pig. 2) (4). These domain-sized water-phase particles may be one source of the observed domain stmcture (7). 

Uses. Approximately 70% of the U.S. production is used to make poly(tetramethylene ether glycol) [25190-06-1] (PTMEG), also known as poly-THE, which is used in the production of urethane elastomers, polyurethane fibers (ether-based spandex), and copolyester—ether elastomers. PTMEG is also the fastest growing use (see PoLYETPiERS, TETRAHYDROFURAn). The remaining production is used as a solvent for the manufacture of poly(vinyl chloride) cements and coating, precision magnetic tape, a reaction solvent in the production of pharmaceuticals, and other miscellaneous uses. 

Poly(A7-vinylcarbazole) [25067-59-8], Ppted seven times from tetrahydrofuran with MeOH, with a final freeze-drying from benzene. Dried under vacuum. 

Poly(vinyl carbazole) is insoluble in alcohols, esters, ethers, ketones, carbon tetrachloride, aliphatic hydrocarbons and castor oil. It is swollen or dissolved by such agents as aromatic and chlorinated hydrocarbons and tetrahydrofuran. 

Aromatic amine-terminated poly(tetrahydrofuran) — 650 MW Amine chain extender —4,4 -methylene bis(3-chloro-2,6,-diethyl aniline) Note the amine chain extender must be melted into the polyol at 160°C for 3 hrs under stirring, until completely melted. Once cooled, the chain extender remains liquid in the polyol. 

Tetrahydrofuran (THF) is usually the solvent of choice for poly (acrylates). It is an excellent thermodynamic as well as kinetic solvent, its only drawback being its volatility and flammability. 

Cationic polymerization of tetrahydrofuran with the or bis(3,5-di-bromomethyl) benzoyl peroxide and AgPp6 pairs of 4,4 -bromomethyl benzoyl peroxide and AgPp6 yield active poly-THP having peroxide group in the main... 

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