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THF polymers

Table V shows the concentrations of polymer (usually in THF/polymer/monomer mixtures), the GPC that they were directly injected into, and the Column Code involved (Ref. Table 1). No effect of different concentration was observed in the chromatograms from GPC 2 when concentrations of samples A to E inclusive were changed by 33%. GPC 1 chromatograms were too disturbed by sampling to be useful except as a rough guide to sampling position. Table V shows the concentrations of polymer (usually in THF/polymer/monomer mixtures), the GPC that they were directly injected into, and the Column Code involved (Ref. Table 1). No effect of different concentration was observed in the chromatograms from GPC 2 when concentrations of samples A to E inclusive were changed by 33%. GPC 1 chromatograms were too disturbed by sampling to be useful except as a rough guide to sampling position.
Polyether 618 The sulfonium polyelectrolyte 617 was dissolved in a minimal amount of methanol. The solution was stirred for 1 week under argon, during which pendant polyether 618 precipitated from the solution. The tacky yellow material was completely soluble in CHC13 and THF. Polymer 618 can be dissolved in THF and passed through a 0.2-mm filter for GPC or for use in film casting and device fabrication. Cast films can be completely redissolved into CHC13 or THF. GPC in THF (polystryrene standards) gave A/w = 91,500 and Mn = 33,800. [Pg.246]

The addition of gem-disubstituted olefins, CH2=CXY, on polysilane 2 also worked well [23,24], For example, the addition of 2-methoxypropene and methylenecyclohexane afforded the expected adducts with 73% and 77% degrees of substitution, although a higher loss of molecular weight with respect to the hydrosilylation of monosubstituted olefins is observed. Copolymer 21, containing both mono- and disubstituted olefins, was made from 2 in a single reaction by adding 50 mol% vinyl acetic acid and an excess of 2-methoxypro-pene to the THF-polymer solution [24],... [Pg.196]

Of course the tertiary amine terminated polymer thus produced Is capable of being quaternlzed by alkyl halides and this has been confirmed experimentally. Moreover, It can be reacted with further living polyTHF to yield a polymer possessing a quaternary ammonium salt moiety at a point along the chain controlled by the relative molecular weights of the two living THF polymers reacted In the system, and again experiments have shown this to occur. [Pg.351]

In the plant used for academic purposes [4], both the solvent and exhausted CO2 are wasted. In an industrial plant both streams should be recycled after purification, for obvious economic reasons. The precipitator size and plant-flow-rates are obtained by increasing 80-fold the relative quantities used in the pilot plant [4]. This scale factor was suggested by the company that supplied the drug. Two vessels, P, in parallel are needed while the former is running, the latter can be cleaned and the solid product can be recovered. Cleaning and product-recovery expenses are not directly evaluated in this example. In the pilot plant, the flow of THF-polymer-drug solution was 0.072 kg/h, and the CO2 flowed in the quantity of 1.08 kg/h (the ratio CO2 to solution equals 15). The precipitator was a 0.4-liter vessel. The actual precipitator scale-up is not considered here. The main factor to consider in scaling-up the precipitator is the nozzle scale-up. The nozzle-size, nozzle-shape, and number of nozzles per reactor volume, determine the precipitate size in a complex and still incompletely understood way [5-8], It is assumed that issues related to the injectors are already solved. [Pg.461]

The water content greatly influences the activity and the molecular weight of PTMG, as shown in Fig. 25. At the ratio of H2O/PW12O40 = 10, the reaction mixture consists of two liquid phases the upper phase is mainly THF and the lower phase is the complex of H3PW12O40 and THF (in the catalyst phase). The THF polymer is formed in the catalyst phase and is transferred to the THF phase. This phase-transfer polymerization is illustrated in Fig. 26. [Pg.157]

The symbols m2 and M2 always refer to the THF, polymer and monomer, respectively. Positive subscript fe s refer to the forward reactions and negative subscript fe s to reverse reactions as usual. The scheme is based on several facts and assumptions ... [Pg.321]

The study of Sisson and Giddings [3] shows that polymer retention in some binary solvents can be enhanced while retention is relatively unaffected or even diminished in other cases. In the case of a mixture of 30% dodecane and 70% THF, polymer retention was enhanced by 35% relative to pure THF. The low end of the molecular-weight range, which can be analyzed by ThFFF, therefore, can be expanded further down by using binary carriers. [Pg.1507]

Iodo-N-BOC-piperidine 42 was obtained by iodination of 4-hydroxy-Af-BOC-piperidine 41 with iodine/triphenylphosphine/imidazole in THE. An extractive workup removed the triphenylphos-phine oxide, allowing a direct crystallization of the pure iodide from ethanol/water that typically contained <1 mol% of triphenylphosphine oxide and other by-products. DMAC was later identified as a better solvent to avoid the formation of THF-polymer or dimer impurities resulting from the interaction of I2/THF. [Pg.77]

Obtained from analysis of THF polymer solutions using polystyrene standards. DSC data collected at a heating rate of at 10°C/min. ... [Pg.330]

Beginning in 1999, Kiebooms and Wudl reported the production of isothianaphthene analogs as shown in Scheme 12.29 [168]. After the removal of lower My, fractions by Soxhlet extraction with methanol and THF, polymer 124a was isolated as a purple solid that was found to be only soluble in 1,1,2,2-tetrachloroethane. It was found that the initially isolated material was partially doped, but could be dedoped by conventional hydrazine treatment. From the absorption onset of solvent cast films, the Eg was determined to be 1.2-1.5 eV [168,169]. Characterization of the IRAV modes correlated with the generation of charge within the doped polymer revealed sharp bands of quite low intensity, indicative of strongly localized charge carriers [98,169]. [Pg.469]

Tadros ThF. Polymer colloids. In Buscall R, Corner T, Stageman J, eds. Applied Sciences. London Elsevier, 1985 105. [Pg.126]

INFL UENCE ON THE FREE VOL UME OF THE MEDIUM OE SYNTHESIS AND OE THE SOLVENT FROM WHICH THF POLYMER FILMS WERE CAST... [Pg.62]

An adipic acid-diethylene glycol copolymer, by treatment with a THF polymer or polypropylene glycol in the presence of chlorosulfonic acid, afforded polyether polyesters useful for the preparation of thermoplastic block copolyester rubbers and polyurethans. Strongly acid sulfonate derivatives of hydrophilic polymers may be prepared by reacting glycidyl methacrylate-ethylene dimethacrylate copolymer or ethylene dimethacrylate-glycidyl methacrylate-styrene copolymer with chlorosulfonic acid or oleum at 0-60 °C. ... [Pg.249]

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... [Pg.2295]


See other pages where THF polymers is mentioned: [Pg.985]    [Pg.360]    [Pg.363]    [Pg.627]    [Pg.359]    [Pg.360]    [Pg.360]    [Pg.360]    [Pg.360]    [Pg.361]    [Pg.363]    [Pg.364]    [Pg.326]    [Pg.279]    [Pg.77]    [Pg.183]    [Pg.86]    [Pg.362]    [Pg.235]    [Pg.495]    [Pg.177]   


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