The Journal of Physical Chemistry B · 2000 · 13 citations · 19 references
Natural SciencesChemistryMaterials ScienceCrystal StructureMaterials ChemistryPhysical ChemistryCrystal SystemsCrystalline MaterialsCrystallographyElectron DiffractionX-ray CrystallographyX-ray DiffractionBridge Wax PatternsCrystal Structure RefinementCrystalline LamellaeDiffraction PatternsElectron Diffraction TheoryLamellar MorphologyLamellar StructureWax Crystal Morphology
Single-crystal structures of two synthetic waxes were solved in projection from electron diffraction data to show that the bridged lamellar model for low molecular weight linear polyethylenes is again expressed. Shell “Callista 158” often crystallizes to mimic n-C35H72 with an average lamellar spacing of c/2 = 47.2 Å. Sasol “Paraflint” wax can crystallize to resemble n-C63H128 with an average lamellar spacing of c/2 = 82.0 Å. Both materials pack in space group A21am with a ≈ 7.42, b ≈ 4.96 Å. No evidence is found for extensive methyl branch inclusion in the lamellae and the sharp 0kl diffraction patterns extend to 1.1 Å (or higher) resolution. Crystal structure models agree well with observed diffraction amplitudes (R = 0.23 in both cases).
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