The structure of noncrystalline regions of HDPE oriented filaments prepared by two different techniques with various degrees of orientation X has been studied by density measurements, small-angle X-ray scattering and DTA. It is shown that at A > 10 the noncrystalline regions of the oriented structure prepared from a crystallized material have 80 nrn voids (pores) in addition to an amorphous phase. The volume fraction of pores grows with increasing A. If a sample is prepared by crystallization from apre-orientedmelt, it does not contain discontinuities, and its noncrystalline regions consist of the amorphous material alone. In this case the density of the amorphous phasedoes not depend on the degree of sample orientation and has a constant magnitude typical of highly oriented PE samples.
PODDUBNY, LAVRENTYEV ct al. : X-ray studies of smectic-crystal and crystal-smectic transition in oriented polypropylene Acta Polymerica 33 (1982) Heft 8 483 X-ray studies of smectic-crystal and crystal-smectic transition in oriented polypropyleneThe results of the study of polypropylene crystallization from the oriented paracrystalline state and the transition to the smectic state observed during isometric melting of the samples crystallized in this manner are interpreted from tlic viewpoint of structural transition in helical polypropylene macromolecules inevitably involving the local melting of helices. Rontgenographische Untersuchung der tibergange zwischen kristalliner und smektischer Phase in orientiertem PolypropylenDie Kristallisation von Polypropylen im orientierten parakristallincn Zustand und der fibergang in den smektischen Zustand beim isometrischen Schmelzen der kristallisiertcn Probe11 wurden untersucht. Die Ergebnisse werdcn unter der Annahme struktureller Umwandlungen der makromolekularcn Helices intcrpretiert, was ein lokales Schmelzen der Helices voraussetzt. PenmzenoecEoe uccneaosanue nepexoda Kpucmaiin -CfieKmuqecicaz$a3a e opuewnuposannofi nonunponunene Pe3yJIbTaTbI 118yYeHMJI KpHCTanJI113aqETH IIOJIHIIpOnktneHa 113 OpMeHTHpOBaHHOrO IIapaKpMCTannHYeCKOrO COCTORHAFI, a TaKme Ha6JIIOnaeMbIfi npll A30TepMH9eCKOM IIJIaBJIeHAH 3aKPHCTaJIJIM30BaHHbIX TaKRM 06pa30M 06pa3uo~ IIepeXOA B CMeKTHYeCKOe COCTORHAe 06'bJICHRH)TCJI C II03HqllH CTPYKTyPHbIX IIepeCTpOeK B CIIllpaJIbHbIX MaKpOMOJIeKynaX nonmponaneaa, ~ena6eltc~o B K~I O Y~I O~H X noKanhHoe nnaBneHHe cnapanefi.
The existence of the specific metastable phase made it possible to carry out multistage electron microscopic investigation of the supermolecular structure formation in the crystallization of polypropylene in the oriented state. Comparison with the data of electron diffraction yielded a direct evidence of the fact that the formation of structural units of the supermolecular organization of crystalline PP, i.e. fibrils and lamellae, occurs in the stage of orientation, and crystallization itself oiily fixes these structures. Eine Moglichkeit zur Beobachtung des Strukturbildungsprozesses bei der Kristallisation Yon PolypropylenDie Existenz einer spezifischen metastabilen Phase erlaubt es, mehrstufige elektronenmikroskopische Untersuchungen der Bildung der iibermolekularen Struktur bei der Kristallisation von Polypropylen im orientierten Zustand durchzufiihren. Der Vergleich mit Elektronenbeugungsaufnahmen liefert einen direkten Beweis dafur, daB die Bildung von Struktureinheiten der iibermolekularen Ordnung im kristallinen Polypropylen, d. h. der Fibrillen und Lamellen, wahrend der Orientierung erfolgt und die Kristallisation diese Strukturen nur fixiert. 0 e03,wmicnocmu nabsloaenu~c npoyecca cmpy~mypoo6pa3oeanu~ npu Kpucmannuaayuu nosunponwna H a m w e CIleqH@H'IeCKOt MeTaCTa6HJIbHOfi @a3bI II03BOJIUJlO IIpOBeCTH 3 J I e K T P O H H O M H K P O C K O I I H~~C K O~ HCCJIeAO-BaHHe 3TaIIOB 06pa30BaHHR Ha~MOJIeKyJIRpHOfi CTpyKTypbI IlpH KpHCTaJIJlH3aqHX IlOJIHIIpOIIHJIeHa B OpMeHTHpO-BaHHOM COCTORHHH C IlepeXOAOM qepe3 3TY @By. COIIOCTaBJIeHHe C AaHHbIMH 3JIeKTpOHHOfi AH@paKqHH IIpRMO yKa-3bIBaeT H a TO, 9TO 06pa30BaHHe CTPJ'KTYPHbIX eAHHHU HaAMOJIeKyJIIIpHOt Opl'aHH3aqHH KpHCTaJIJIHW3CKOrO nn, @ H~~H J I J I H JIaMeJIefi, IlpOHCXOAHT H a CTaAHH OpHeHTaUHH, a CO6CTBeHHO KpHCTaJIJIH3allMR JIHIIIb @HKCHpyeT BTH CTPYIETYPbI.
Acta Polymericr 41 (1990) Nr. 3 1 47 aM. Figure 2 shows also the discrepancy between curves of NOE(w,B) a t aM = 54 (approximate solution) and corresponding t o a = 45 for precise solution. The value of parameter a M is one of the values which have been obtained in ref. [4] on the base of eqs. (13), (17) and experimental data for aromatic/aliphatic polyester in CDCl,.The crystallization of flexible-chain polymers capable of forming different polymorphous modifications was considered by using the thermodynamic approach and taking into account kinetic factors. Taking as examples poly(caproamide) and poly(viny1idene fluoride), the changes in free energies in the generation of different crystalline forms were calculated and phase diagrams were plotted in the coordinates degree of coiling of macromolecules and temperature. It was thus possible to establish the thermokinetic conditions for the formation of equilibrium and metastable modifications and the transitions between them. Thermokinetische Analyse der polyrnorphen Tramformationen bei der Kristallisation und Orienfierung von flexibelkettigen PolymerenDie Kristallisation von flexibelkettigen Polymeren, die unterschiedliche polymorphe Modifikationen bilden konnen, wurde unter thermodynamischen Aspekten und unter Berucksichtigung kinetischer Faktoren betrachtet. An den Beispielen Poly(caproamid) und Poly(vinylidenf1uorid) wurden die Anderungen der freien Energie bei der Bildung unterschiedlicher kristalliner Modifikationen berechnet, und Phasendiagramme in den Koordinaten Knauelungsgrad der Makromolekule und Temperatur wurden dargestellt. Auf diese Weise war es moglich, die thermokinetischen Bedingungen fur die Bildung der Gleichgewichts-und der metastabilen Modifikationen sowie fur die Uhergange zwischen ihncn anzugeben. TepfiommemuuecicuC. urbaaua noauopg(inazx npeepau{efiuG npu r;pucmannuaayuu u opuerbmayuu 2 u 6~o q e n~b u noamepocHa OCHOBe TepMOAHHaMHYeCKOI'O IIOAXOAa C YYeTOM KHHeTHYeCKHX @aKTOpOB IIpOBeAeHO PaCCMOTpeHHe IIpOIleCCa K P R C T~J I J I H~~~H H r m b~o q e n~b~x nOJIBMepOB, CIIOCO6HbiX K 06Pa30BaHHIO pa3JlHYHblX IIOJIHMOp@HMX MOAH@HKaqHn. Ha IIpHMepe IIOJlIIKaIIpOaMHAa R IIOJlHBHHHnHgeH@TOpUAa PaCCYIITaHM H3MeHeHIIR CBO6OAHbIX BHeprHi IIpB o6pa-30BaHBH Pa3JlHYHbIX KPHCTaJl.JlBYeCKBX @OPM H IIOCTpOeHM @a30BbIe AHaI'paMMbI B KOOpAHHaTaX: CTeIIeHb CBepHy-TOCTR MaKpOMOJleKyJl -TeMIIepaTypa, n03BOnMBIIJHe YCTaHOBHTb TepMOKHHeTHYeCKBe YCJlOBHR BO3HHKHOBeHHR paBHOBeCHbIX €3 leTaCTa6HJIbHbIX MOAH@RKal@ R IIepeXOAbI MeXgy HBMII.
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