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Polyethylene isothermal thickening

The isothermal thickening (avoiding very short times) of mature crystals of conventional polyethylenes follows the equation [55] ... [Pg.42]

This shows that by means of synchrotron radiation, for the first time the primary lamellar thickening on melt crystallization in polyethylene could be observed. This enabled also the determination of the true crystal thickness as a function of supercooling AT. Most satisfyingly it was found to be closely identical to that obtained in solution crystallization were no isothermal thickening takes place. In conclusion, the hitherto existing gap between melt and solution crystallization has been removed and the corresponding f versus AT curves brought in coincidence. [Pg.41]

Hoffman JD, Lauritzen J (1961) Crystallization of bulk polymers with chain folding theory of growth of lamellar spherulites. J Res Natl Bur Stand A65(4) 297-336 Hoffman JD, Miller RL (1997) Kinetic of crystallization from the melt and chain folding in polyethylene fractions revisited theory and experiment. Polymer 38(13) 3151-3212 Hoffman JD, Weeks JJ (1965) X-Ray study of isothermal thickening of lamellae in bulk polyethylene at the crystallization temperature. J Chem Phys 42(12) 4301-4302... [Pg.139]

Polyethylene crystals thicken at temperatures greater than 110°C. Polymer crystals grown under isothermal conditions thicken gradually with time. This has numerous important consequences. For... [Pg.142]

Hoffman JD, Weeks JJ. X-ray study of isothermal thickening of lamellae in bulk polyethylene at the crystallization temperature. J Chem Phys 1965 42 4301-4302. [Pg.256]

Abo el Maaty MI, Bassett DC (2005) Evidence for isothermal lamellar thickening at and behind the growth front as polyethylene crystallizes from the melt. Polymer 46 8682-8688 Abo el Maaty MI, Bassett DC (2006) On the time for fold surfaces to order during the crystallization of polyethylene from the melt and its dependence on molecular parameters. Polymer 47 7469-7476... [Pg.95]

Abo El Maaty MI, Bassett MD (2005) Evidence for isothermal lamellar thickening at and behind the growth front as polyethylene crystallizes from the melt. Polymer 46(20) 8682-8688... [Pg.138]

Different from s-PP, crystallites of polyethylene thicken with time. This was clearly demonstrated by time-dependent SAXS experiments carried out during an isothermal crystallization [6]. Fig. 4 shows a typical result, in a comparison of the interface distribution function K" z) obtained at the beginning and the final stage of the crystallization process. [Pg.146]

See other pages where Polyethylene isothermal thickening is mentioned: [Pg.418]    [Pg.4959]    [Pg.187]    [Pg.268]    [Pg.176]    [Pg.186]    [Pg.186]    [Pg.42]    [Pg.207]    [Pg.117]    [Pg.4946]    [Pg.4950]    [Pg.281]    [Pg.60]    [Pg.187]    [Pg.237]    [Pg.580]   
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