Tetrahydrofuran homopolymer

Tetrahydro-2-furancarbinol. See Tetrahydrofurfuryl alcohol Tetrahydrofuran, compd. with carbonic acid. See Polyether-polycarbonate diol Tetrahydrofuran homopolymer. See Polytetramethylene ether glycol Tetrahydro-2-furanmethanol. See Tetrahydrofurfuryl alcohol Tetrahydro-2-furanmethanol acetate. See Tetrahydrofurfuryl acetate Tetrahydro-2-furanone. See Butyrolactone Tetrahydrofurfuryl acetate CAS 637-64-9 EINECS/ELINCS 211-296-8 FEMA 3055... 

These solvents include tetrahydrofuran (THF), 1,4-dioxane, chloroform, dichioromethane, and chloroben2ene. The relatively broad solubiHty characteristics of PSF have been key in the development of solution-based hoUow-fiber spinning processes in the manufacture of polysulfone asymmetric membranes (see Hollow-fibermembranes). The solvent Hst for PES and PPSF is short because of the propensity of these polymers to undergo solvent-induced crysta11i2ation in many solvents. When the PES stmcture contains a small proportion of a second bisphenol comonomer, as in the case of RADEL A (Amoco Corp.) polyethersulfone, solution stabiHtyis much improved over that of PES homopolymer. 

BAMO is perhaps the most prominent among the azido oxetanes class in terms of the number of polymers and copolymers reported so far. Due to its symmetrical azido groups, it assumes special significance as a hard block repeating unit in a thermoplastic elastomer. However, the homopolymer is solid and cannot be used directly for binder applications because of its crystal-tine nature. Also, poly(BAMO) shows relatively poor mechanical properties as a binder for solid rocket propellants [153]. Many copolymers of BAMO with non-energetic co-monomers tike tetrahydrofuran (THF) have been reported. The BAMO-THF copolymer is an excellent candidate for binder applications with its energetic BAMO content coupled with the THF block which affords... 

Blends of various compositions of PDMS (Mw, 650,000 M , 253,000) and PS (Mw, 100,000) were prepared by dissolution of the homopolymers in tetrahydrofuran, mixing the solutions and then rapidly removing the solvent using a freeze-drier. Blends were dried in a vacuum oven at 55 °C, sealed in... 

Graft copolymers were prepared by polymerizing ethylene oxide onto the PVN polyradical anion (10), The latter was obtained by reaction of PVN with cesium in tetrahydrofuran solution. The copolymers were extracted with water to remove the PEO homopolymer which was formed as a byproduct. Experimental details and evidence for bond formation between ethylene oxide and the aromatic moiety were presented elsewhere (//). 

Not all monomers are anionically polymerizable. Nevertheless, one can take advantage of the activity of the living ends to introduce reactive end groups at the extremity of homopolymers and then use such end groups to initiate the polymerization of anionically non polymerizable monomers. This method has been applied to the synthesis of copolymers with polyvinyl and polylactone blocks19 and of copolymers with polyvinyl and polypeptide blocks20-2S). One can at last use both anionic and cationic polymerization to prepare block copolymers of tetrahydrofuran with styrene or methylstyrene2. ... 

The homopolymer of 1,4-disiloxy-1,4-dimethyl-1,4-disilacyclohexadiene was prepared as shown in Scheme V. In this case, 3.89 g of 1,4-dimethyl-1,4-disilacyclohexadiene-l,4-di(potassium silanoate) was dissolved in 10 mL of water and titrated to the phenolphthalein end point with glacial acetic acid. A precipitate was formed ether was added until two transparent liquid phases resulted, and the upper organic phase was removed. Removal of the ether by evaporation under vacuum yielded 1.59 g of a tan, cloudy, viscous product. The solution viscosity (tetrahydrofuran, 30 °C) was 0.142 dL/g. The IR spectrum showed absorption bands at 2933 (mw), 1255 (m), and 822 (m) cm (Si-CHa) 1035 (s, Si-O-Si) and 1340 (m, associated... 

A selection of literature values for Mark-Houwink constants K and a in tetrahydrofuran, which is the eluent most commonly used in size-exclusion chromatography, is collected in Table 1 for the principal polymer structures. An accurate, more extensive compilation of the same constants for homopolymers and copolymers may be found in Ref. 22. 

Extremely strong solvents such as THF (tetrahydrofuran) or cyclohexanone are frequently suggested for use with homopolymer resins. Figure 2 shows the typical solubility of these resins in THF. 

A very interesting group of random copolyethers is obtained by anionic copolymerisation of EO (a highly hydrophilic monomer) with BO (a highly hydrophobic monomer). Because EO does not isomerise to double bond structures and BO has a much lower tendency to isomerise to allyl structures than PO (see Chapter 12.2), the BO-EO copolyethers have a very low unsaturation level compared to PO homopolymers or even PO-EO copolymers [82]. This variant of polyether polyols synthesis in the form of BO-EO copolymers is a very interesting way to obtain low unsaturation polyether polyols directly from synthesis. Another group of low unsaturation polyether polyols, obtained directly from synthesis, are the tetrahydrofuran (THF)-EO and THF-PO copolymers synthesised with cationic catalysts (see Chapter 7.3). 

Lambert and Goethals attempted to prepare block copolymers of tetrahydrofuran (THF) with propylene sulfide, thiethane, 3,3-dimethylthiethane, aziridine and l-(2-phenylethyl)-2-methyl-aziridine123). None of these systems gave pure block copolymers. Except with aziridine, mixtures of block copolymers and polyTHF was found from solubility data. With unsubstituted aziridine transfer led to a mixture of homopolymers ... 

STA Stacy, C.J. and Kraus, G., Second virial coefficients of homopolymers and copolymers of butadiene and styrene in tetrahydrofuran, J. Polym. Sci., Polym. Phys. Ed, 17, 2007, 1979. 

Near-IR spectroscopy (10000-4000/cm) was successfully used to monitor conversion dining conventional, anionic solution polymerisation of styrene and isoprene to homopolymers and block copolymers. The conversion of the vinyl protons in the monomer to methylene protons in the polymer was easily monitored under conventional (10-20% solids) solution polymerisation conditions. In addition to the need for an inert probe, high sampling frequencies were required since polymerisation times ranged from 5s in tetrahydrofuran to 20 minutes in cyclohexane. Preliminary data indicate that near IR is capable of detecting sequence distribution for tapered block copolymers, geometric isomer content, and reactivity ratios for free-radical copolymerisation. 20 refs. USA... 

---