Thermodynamics of the melting of pseudoeutectic linear copolymers systems

Crystalline and supermolecular structures in linear polyethylene irradiated with fast electrons

“…8) ,,ff o~o, ,,$o~ of The possibility, that different crystallization processes proceed concurrently, the relative strength of them depending on the amount of non-crystallizable units, has already been discussed in the literature [8,25]. For defect concentrations eL< 2% = e~ ~ a folded lamellar growth of crystals is expected to dominate, for higher ez-values a fringed micellar one [26,27]. In the latter, the defect points are excluded from the growing crystal, the process being describable theoretically as crystallization of an eutectic multi-component system.…”

A novel concept in describing elastic and plastic properties of semicrystalline polymers: polyethylene

“…The molar mass fraction of the MPs, wp, including the defective parts of each c-sequence, has been shown to be given by [14]:…”

“…The excess term ge, takes care of the average difference in enthalpy between the boundary and the melt. The melting temperature of an "infinitely large" crystal is defined as Tm= Ah/ds (14) where Ah and As are the usual molar-melting enthalpy and -melting entropy per chain unit respectively. The dependence upon temperature of Ah is given by [14]: (15) and AC is the molar temperature coefficient of the melting enthalpy.…”

Synthesis and melting behavior of poly(ethylene) copolymers obtained by polymeranalogous reaction

“…The chlorinated polyethylenes (CPE) thus obtained are a class of substances which have significant interest in technical applications (2, 3) as well as in academic studies. The latter is particulary true for studies concerning the relation between molecular structure and morphology (4-6) as well as thermal or mechanical properties of semicrystalline copolymers in general where CPE was used as an easily available model (7)(8)(9)(10)(11). Among others the question has been discussed if and to what extent the.…”

“…A number of authors has, however, assumed that the CHCIgroups do not cocrystallize with the -CH2-groups but stay in the amorphous regions (7,10,11). It was consequently assumed that the sequence length distribution is the determining factor for crystal size distribution as well as for the overall degree of crystallinity at a given copolymer composition following Flory's original treatment (12) or more sophisticated models (11,13) of the behavior of crystallizable copolymers (exclusion model). Other authors did not follow these arguments and adopted models of the crystallization behavior in which part or all *) Herrn Professor Dr. G. Rehage zum 60.…”