A possibility of observing the structure forming process in polypropylene crystallization

Abstract

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.

Morphological studies of elongated PMMA by excimer formation

“…Grosskurth 4 concluded that its morphology depends on the degree of molecule orientation but is independent of the method of orientation. Bezruk et al 5 pointed out that the morphological changes of PMMA films are similar to those of amorphous-crystal polymers during the uniaxial elongation.…”

“…Hence, a number of techniques have been used to investigate the structural changes of amorphous polymers during drawing process. These include WAXD, 2,3 electron microscopy, 4,5 etc.…”

Morphological studies of elongated PMMA by excimer formation

“…Grosskurth4 concluded that its morphology depends on the degree of molecule orientation but is independent of the method of orientation. Bezruk et al5 pointed out that the morphological changes of PMMA films are similar to those of amorphous‐crystal polymers during the uniaxial elongation.…”

“…Hence, a number of techniques have been used to investigate the structural changes of amorphous polymers during drawing process. These include WAXD,2, 3 electron microscopy,4, 5 etc.…”