Kinetics of crystallization and melting behaviour of poly(ethylene naphthalene-2,6-dicarboxylate)

Structural Change of High-Speed Spun Poly (ethylene 2,6-naphthalene dicarboxylate) Fibers with Annealing.

“…The relation between sample thickness t and absorbance can be described as follows. (2) where Io and I are the incident and transmitted X-ray intensities, and u is the absorption coefficient of PEN polymer calculated from the chemical formulae and density. Using the obtained sample thickness, the integrated intensity I can be converted to the standardized integrated intensity I* as follows.…”

Effect of drawing stress on mesophase structure formation of poly(ethylene 2,6-naphthalene dicarboxylate) fiber just after the neck-drawing point

“…Buchner et al have suggested that every naphthalene ring is twisted around the chain axis by about 180° in the β-crystal. 2 It was also reported that the β-crystal can be formed when the isotropic melt is crystallized at temperatures higher than 220°C. 2,3 There have been previous studies on hot-drawing and cold-drawing processes for PEN fibers and films, 4,5 wherein the drawability of amorphous PEN was reported to depend on the molecular weight and strain rate.…”

“…2 It was also reported that the β-crystal can be formed when the isotropic melt is crystallized at temperatures higher than 220°C. 2,3 There have been previous studies on hot-drawing and cold-drawing processes for PEN fibers and films, 4,5 wherein the drawability of amorphous PEN was reported to depend on the molecular weight and strain rate. The structural changes upon neck drawing of amorphous PEN films have been investigated through off-line measurements using synchrotron X-ray radiation, 4,6 which revealed the appearance of smectic order with a period of 1.25 nm corresponding to a chain repeat length associated with a sinusoidal conformation of the polymer chains.…”

“…1 The β-crystal is also triclinic but has significantly different unit cell parameters of a=0.926 nm, b=1.559 nm, c=1.273 nm, α= 121.6°, β= 95.57°, and γ= 122.52°. 2 The α-and β-crystal densities are 1.407 and 1.439 g/cm 3 , respectively. The β-crystal has a higher crystal density and shorter c-axis length than the α-crystal.…”

Preferential Orientation of Poly(ethylene 2,6-naphthalate) Melt-Crystallized on the Friction-Transfer Layer of PTFE.

“…The inter-stem distance in the (100) plane of PTFE is reported as 0.566nm [22], and that in the (100) plane of PEN a-form is:computed to be b -sing = 0.568nm. Therefore, the degree of lattice mismatch is estimated at [11]. However, further investigation is needed to associate this reflection with the /3-form or a new crystal modification of PEN.…”