Supermolecular structures and mechanical properties of isotactic polypropylene films

Abstract We examined mechanical and morphological properties of fully transcrystalline polypropylene grown from the surface of poly(tetrafluoroethylene) sheets. Comparison of mechanical properties between transcrystalline and spherulitic polypropylenes demonstrated that Young’s modulus is dependent on the crystallinity and independent of the supermolecular structure. On the other hand, the mechanical yielding process was predominantly affected by the supermolecular structure, and the mechanical energy required for yielding of transcrystalline sheets was greater than that of the spherulitic morphology. In addition, it was found that mechanical necking is required for the alignment of lamellae in the stretching direction. This means that the unfolding process of lamellae orienting in the stretching direction is associated with necking and ductility.

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Morphology and mechanical properties of poly (phenylene sulfide)/isotactic polypropylene in situ microfibrillar blends

Polymer Engineering & Science ◽

10.1002/pen.20406 ◽

2005 ◽

Vol 45 (9) ◽

pp. 1303-1311 ◽

Cited By ~ 25

Author(s):

Hui Quan ◽

Gan-Ji Zhong ◽

Zhong-Ming Li ◽

Ming-Bo Yang ◽

Bang-Hu Xie ◽

...

Keyword(s):

Mechanical Properties ◽

Isotactic Polypropylene ◽

Morphology And Mechanical Properties ◽

Phenylene Sulfide

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Transcrystallization of Isotactic Polypropylene/Bacterial Cellulose Hamburger Composite

Polymers ◽

10.3390/polym11030508 ◽

2019 ◽

Vol 11 (3) ◽

pp. 508 ◽

Cited By ~ 2

Author(s):

Bo Wang ◽

Fu-hua Lin ◽

Xiang-yang Li ◽

Xu-ran Ji ◽

Si-xiao Liu ◽

...

Keyword(s):

Mechanical Properties ◽

Bacterial Cellulose ◽

Isotactic Polypropylene ◽

Crystallization Rate ◽

Sem Analysis ◽

Hydroxyl Groups ◽

Hot Press ◽

Ft Ir ◽

Ir Analysis ◽

The Fourier Transform

Isotactic polypropylene (iPP) is a commonly used thermoplastic polymer with many excellent properties. But high brittleness, especially at low temperatures, limits the use of iPP. The presence of transcrystallization of iPP makes it possible for fiber-reinforced iPP composites with higher strength. Bacterial cellulose (BC) is a kind of cellulose with great potential to be used as a new filler to reinforce iPP due to its high crystallinity, biodegradability and efficient mechanical properties. In this study, the iPP/BC hamburger composite was prepared by a simple hot press and maleic anhydride grafted polypropylene (MAPP) was used to improve the interface compatibility of iPP and BC. The polarizing microscope (POM) photograph shows that BC successfully induces the transcrystallization of iPP. The differential Scanning Calorimeter (DSC) date proves that the addition of BC could improve the thermal properties and crystallization rate of the composite. Especially, this change is more obvious of the iPP/MAPP/BC. The mechanical properties of the iPP/BC composites were greatly increased. This DSC date is higher than BC; we used BC particles to enhance the iPP in our previous research. The scanning Electron Microscope (SEM) analysis intuitively shows that the interface of the iPP/MAPP/BC is more smooth and flat than the iPP/BC. The fourier Transform infrared spectroscopy (FT-IR) analysis of the iPP/BC hamburger composites was shown that a new C=O group vibration appeared at 1743 cm−1, which indicated that the hydrogen bond structure of BC molecules was weakened and some hydroxyl groups were substituted after modification which can increase the lipophilicity of BC. These results indicated that the BC fiber can easily induce the transcrystallization of iPP, which has excellent mechanical properties. Moreover, the addition of MAPP contributes greatly to the interface compatibility of iPP and BC.

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