Poly tetrahydrofurane

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. 

With respect to the initiation of cationic chain polymerizations, the reaction of chlorine-terminated azo compounds with various silver salts has been thoroughly studied. ACPC, a compound often used in condensation type reactions discussed previously, was reacted with Ag X , X, being BF4 [10,61] or SbFa [11,62]. This reaction resulted in two oxocarbenium cations, being very suitable initiating sites for cationic polymerization. Thus, poly(tetrahydrofuran) with Mn between 3 x 10 and 4 x lO containing exactly one central azo group per molecule was synthesized [62a]. Furthermore, N-... 

NSE Studies on Entangled Polymer Melts Poly(tetrahydrofurane) (PTHF)... 

The final example in this section is the synthesis of a tristetrahydrofuran 2-606 described by the group of Rychnovsky [313]. Here, the tris(sulfate) 2-605 was converted into 2-606 by simply heating it in a mixture of MeCN and H20 (Scheme 2.138). The domino reaction is most likely initiated by deprotection of the primary alcohol, which then attacks the adjacent sulfonate unit in a SN2-type manner to afford the first furan moiety. Under the reaction conditions the formed acyclic sulfate is hydrolyzed affording a free secondary alcohol which then attacks the next adjacent cyclic sulfate unit. Overall, the SN2/hydrolyzation sequence proceeds three times to finally provide the poly(tetrahydrofuran) 2-606 as a single isomer in 93 % yield. 

CDs were found to form inclusion complexes also with poly(tetrahydrofuran) (PTHF) of different molecular weights. In particular, y-CD gave the complexes... 

In this section, it should be mentioned that star poly(tetrahydrofuran) has been prepared by coupling cationically polymerized THF with multifunctional diethylenetriamine [92] in the presence of 2,2 6,6 tetramethylpiperidine as a proton trap. When the MW of poly(THF) is 1600 seven chains are added to the triamine, when the MW is 8000 a five-arm star has been obtained. 

There are various routes to vinyl macromonomers [Gnanou and Taton, 2002]. For example, the reaction of an HO-terminated polymer such as polysiloxane, polycaprolactone, or poly-tetrahydrofuran with acryloyl chloride... 

Poly(tetrahydrofuran) Toluene, methylene chloride, THF Aliphatic hydrocarbons, diethyl ether... 

Poly(oxytetramethylene), poly(tetrahydrofuran), may assume the state of a viscous oil, a wax, or a crystalline solid (melting range around 55 °C), depending on the molecular weight. Poly(tetrahydrofuran) telechelics prepared with two OH end groups and in molar masses of 500-4000 g/mol are used widely as soft block in segmented polyurethanes and polyesters (see Sect. 3.4.2.1). 

Preparation of a,w-dihydroxylactide-poly[(tetrahydrofuran)-co-(lactide)] prepolymer... 

P. Dreyfuss, Poly(tetrahydrofuran), Gordon Breach, New York, 1982. 

Chenite, A., and Brisse, F. (1992) Poly(tetrahydrofuran)-urea adduct a structural investigation, Macromolecules, 25, 776-782. 

Schmidt, G, Enkelmann, V., Westphal, U., Droscher, M., and Wegner, G. (1985) Preparation of urea-poly(tetrahydrofuran) complexes and their application for fractionation of oligomers, Colloid Polym. Sci. 263, 120-127. 

Reaction of cyclic sulfates with intramolecular O-nucleophiles leads to cyclic ethers and other heterocycles (Table 1). For example, a hydrolysis of compound 39 has produced predominantly the cyclic alcohols 41 (Scheme 4) < 1995JA12873 >. When the reaction was buffered with pyridine, the sulfate ester 40 was isolated rather than the free alcohol. An alcohol function in an intermediate product may give a route to a polysulfate cascade cyclization, which has been successfully realized in the synthesis of poly(tetrahydrofurans) (Table 1) <1995JA12873>. 

DBU DMC DMF EC EO EOS GSS ILs MBMTBP MEA MW PC PDMS PEG PEGda PEO PMPS PO PPG PPGda PTC PTHF PTMO PVP Diazabicyclo[5.4.0] -undec-7-ene Dimethylcarbonate Dimethylform amide Ethylene carbonate Ethylene oxide, oxyethylene Equation of state Gas-saturated solution Ionic liquids 2,2,-methylene-bis(4-methyl-6-tert-butylphenol) Monoethanolamine Molecular weight Propylene carbonate Polydimethylsiloxane Polyethylene glycol Poly(ethylene glycol) diacrylate Polyethylene oxide Poly(methylphenylsiloxane) Propylene oxide Poly(propylene glycol) Poly(propylene glycol) diacrylate Phase-transfer catalyst Poly(tetrahydrofuran) Polytetramethylene oxide Polyvinyl pyrrolidone... 

Non-volatile solvents eliminate the health and environmental risks associated with the use of volatile solvents, but may pose their own risks and separation problems. Several liquid polymers, such as PEG, poly(propylene glycol) (PPG), poly(tetrahydrofuran) (PTHF), Polydimethylsiloxane (PDMS), poly(methylphenyl siloxane) (PMPS), and variations of those with ether or ester end-capping groups, are compared in terms of environmental risk, solvent polarity, and performance as... 

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