On the morphology and crystallization kinetics of monodisperse polyethylene oligomers crystallized from the melt

✍ Scribed by S.J. Sutton; A.S. Vaughan; D.C. Bassett

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 469 KB
• Volume: 37
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/s0032-3861(96)00481-8

✦ Synopsis

The melt crystallization of three monodisperse paraffins, C zg4 H optically as a function of temperature. In both C 590, C246H494 and C19aHs9a, has been studied 294 H s9s and &H.+s,d, a distinct minimum in the rate of crystal growth has been observed, corresponding to a transition from predominantly chain-extended crystallization at high temperatures to the growth of crystals in which the molecules adopt a once-folded conformation. This change in molecular conformation is accompanied by a change in optical texture. Well below the minimum, morphologies, are spherulitic and closely resemble polyethylene. When crystals contain chain-extended molecules, highly birefringent, coarse lamellar textures develop. In C198H398, no minimum in the crystal growth rate has been observed; this system does, however, exhibit similar morphological trends to those seen in C294Hsae and C 246 H 494.