Haloaldehyde polymers. IX. Polybromodichloroacetaldehyde

Lipp, David W.; Vogl, Otto

doi:10.1002/pol.1978.170160613

Cited by 9 publications

(3 citation statements)

References 11 publications

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“…There are 10 possible perhaloacetaldehydes with chlorine, bromine, and fluorine as the halogen atoms 29. We prepared and polymerized all 10 trihaloacetaldehydes under conditions similar to those for chloral polymerization.…”

Section: Addition Polymers Of Aldehydesmentioning

confidence: 99%

Effect of temperature and span series surfactant on the structure of polysulfone membranes

Tsai

Ruaan

Wang

et al. 2002

J of Applied Polymer Sci

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A macrovoid structure was found in polysulfone membranes formed by the wet-inversion method using N-methylpyrrolidinone (NMP) and water as the solvent/nonsolvent pair. The addition of Span series surfactants in the casting solution was found to inhibit the macrovoid formation. Sorbitan monooleate (Span-80) was more effective in inhibiting macrovoids than was sorbitan monolaurate (Span-20). The phenomenon of macrovoid suppression became more prominent at higher temperature. The cloud-point shift might account for the temperature effect. But there was no simple explanation for the effect caused by Span-80. The cloud-point position, the demixing rate, and the viscosity of the casting solution were measured. None of them could explain the effect of macrovoid inhibition by the addition of Span-80. However, the penetration test indicated that the penetration of a nonsolvent into a surfactant-free casting solution was caused by a convective flow, but that into Span-80 was through diffusion. It was found that the retardation of nonsolvent penetration was the major cause of macrovoid inhibition.

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Section: Addition Polymers Of Aldehydesmentioning

confidence: 99%

Effect of temperature and span series surfactant on the structure of polysulfone membranes

Tsai

Ruaan

Wang

et al. 2002

J of Applied Polymer Sci

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show abstract

“…Aldehyde polymerizations were initiated above the ceiling T c and cooled at a constant rate, and the point of the first cloud formation was determined. [12][13][14] This could be done with a light sensor to improve the accuracy of the visual measurement. The polymerization temperatures were now measured at several concentrations and then extrapolated to a 1 M concentration.…”

Section: Ceiling Temperatures Of Aldehyde Polymerizationmentioning

confidence: 99%

“…Much of the cryotachensic chloral polymerization occurs in the gel state. 35,36 Fabrication by this technique faces a problem. This technique of monomer casting is associated with a volume shrinkage of about 20 -25% from the monomer to the polymer.…”

Section: Cryotachensic Polymerizationmentioning

confidence: 99%

Haloacetaldehyde polymers and macromolecular asymmetry

Vogl

2000

J. Polym. Sci. A Polym. Chem.

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Haloaldehyde polymers, 12. Preparation and polymerization of bromodifluoroacetaldehyde

Campbell

Vogl

1979

Makromol. Chem.

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Bromodifluoroacetaldehyde (5) was prepared from methyl bromodifluoroacetate (4) by reduction with lithium aluminium hydride. 4 was in turn prepared by bromination of chlorotrifluoroethylene (1) and treatment of the resulting 1,2-dibromo-l-chlorotrifluoroethane (2) with fuming H2S04 and HgO. 5, properly purified, could be polymerized with anionic and cationic initiators to poly[oxy-2-(bromodifluoro)ethylidene] (12). Certain initiators produce partially or entirely amorphous soluble 12 of relatively low molecular weight. Most polymers, however, are insoluble, crystalline, and presumably isotactic. Thermal vacuum degradation of the polymers 12 gave monomer 5 in essentially quantitative yield. The thermal stability of polymers can significantly be improved by endcapping or treating with agents which replace unstable end groups. The ceiling temperature of the polymerization of 5 was determined to be +48"C. 5 was copolymerized with trichloroacetaldehyde with cationic or anionic initiators to copolymers containing predominantly units of 5. 5 could also be copolymerized with phenyl isocyanate to a polymer containing oxycarbamido linkages.

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Haloaldehyde polymers. IX. Polybromodichloroacetaldehyde

Cited by 9 publications

References 11 publications

Effect of temperature and span series surfactant on the structure of polysulfone membranes

Effect of temperature and span series surfactant on the structure of polysulfone membranes

Haloacetaldehyde polymers and macromolecular asymmetry

Haloaldehyde polymers, 12. Preparation and polymerization of bromodifluoroacetaldehyde

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