Morphological Features of Polyethylene and Polyimides by Atomic Force Microscopy
Lamellar crystals of linear polyethylene grown from dilute solution in xylene were observed by atomic force microscopy (AFM). Effects of crystallization conditions, annealing and deformation were studied. Features such as lamellar thickness, fold domain boundaries, wrinkles, and pleats were observed. A temperature growth step, produced due to sudden change in temperature during crystallization, was measured accurately.
Patches, not previously studied, on the fold surfaces of the crystals exist in a range of diameters. Patches were 3–70 nm in diameter and only 0.2–1.5 nm high. Localized changes in thickness of lamella and other morphological changes due to annealing at temperatures from 115° to 135° C were observed in great detail. Shearing of lamellae at overlaps and “accidental” tensile deformations were found.
* regularly repeating sequences synthesized from 3,3′,4,4′tetracarboxylicbiphenyl dianhydride (BPDA) and 2,2′bis(methylmethyl)-4,4′-diaminobiphenyl (PMB)
**1,3-bis(4-aminophenoxy)-2,2′dimethylpropane and 3,3′,4,4′benzophenonetetracarboxylic dianhydride (BTDA).
KeywordsAtomic Force Microscopy Single Fiber Fiber Axis Atomic Force Microscope Data Lamellar Crystal
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