Study of the morphology, thermal and mechanical properties of irradiated isotactic polypropylene films

2010 ◽  
Vol 79 (3) ◽  
pp. 325-328 ◽  
Author(s):  
W.L. Oliani ◽  
L.F.C.P. Lima ◽  
D.F. Parra ◽  
D.B. Dias ◽  
A.B. Lugão
2018 ◽  
Vol 26 (2(128)) ◽  
pp. 26-31 ◽  
Author(s):  
Munir Hussain ◽  
Feichao Zhu ◽  
Feichao Zhu ◽  
Bin Yu ◽  
Bin Yu ◽  
...  

The thermal properties and morphological characterisation of isotactic polypropylene (iPP) homopolymer and its blends with low molecular low modulus polypropylene (LMPP) were studied. Firstly blends were prepared with variant LMPP contents, and their properties were characterised using SEM, DSC, XRD, and DMA. Later the mechanical properties of iPP/LMPP blend fibres were investigated. SEM results showed that the iPP/LMPP blends produced smoother surfaces when the LMPP content was increased, as well as the miscibility. All the Tg values with different LMPP percentages were in-between pure iPP and LMPP. The XRD results indicated the LMPP percentage decreased along with the degree of crystallinity of the iPP/LMPP blends (5% to 15%), which increased and then decreased as compared to pure iPP. The elongation at break increased when the LMPP content increased, with the maximum breaking elongation of the LMPP 25% blend reaching 12.95%, which showed great stretch-ability, whereas the elastic modulus of iPP/LMPP blends decreased.


1964 ◽  
Vol 6 (7) ◽  
pp. 1404-1408 ◽  
Author(s):  
V.A. Kargin ◽  
T.I. Sogolova ◽  
L.I. Nadareishvili

2020 ◽  
Vol 90 (19-20) ◽  
pp. 2136-2148 ◽  
Author(s):  
Aravin Prince Periyasamy ◽  
Martina Viková ◽  
Michal Vik

In this research, metallocene catalyst isotactic polypropylene (miPP) filaments were produced with different concentrations of photochromic pigments to develop ultraviolet (UV) sensing materials. The produced miPP filaments showed good photochromic response under UV irradiation. In this work, six drawing ratios were applied to get the final product (miPP filament). Resultant filaments showed significant photochromic responses, such as Kubelka–Munk values ( K/ S). The interesting observation was that the photochromic response was indirectly proportional to the applied drawing ratio. The photochromic color build was found to be maximum with the highest concentration of pigment as well as the lowest drawing ratio. Overall, it was observed that the thermal properties were significantly dependent on the drawing ratio. The changes in thermal properties, such as T m, ΔH m and ΔS m, for miPP filaments in dependence on photochromic pigment concentration was significantly less as compared to the drawing ratios. The thermal properties improved with the drawing ratio, which directly influenced the crystallinity of produced miPP filaments. The addition of photochromic pigment to the miPP filaments increased the crystallinity by 14%. Also, the lamella thickness increased with increasing the drawing ratio. However, there was no significant effect of pigment concentration on lamella thickness. In this experimental work, the impact of drawing ratio on the optical, thermal and mechanical properties of photochromic miPP filaments was investigated.


2020 ◽  
pp. 089270572096352
Author(s):  
Yousef Ahmad Mubarak

In this study, the effects of two different biodegradable plastic additives on the thermal and mechanical properties of isotactic polypropylene were investigated, analyzed, and presented. Biosphere biodegradable plastic additive and another oxidative biodegradable plastic additive, D2W, were used in 0.25, 0.5, 1.0, 1.5, and 2.0 wt% to prepare two sets of isotactic polypropylene composites. Differential scanning calorimeter and optical polarized light microscope were used to analyze the obtained composites thermally while the mechanical properties of these composites were studied by conducting tensile and impact testing. The morphological results reveal that only monoclinic α spherulites were obtained when the polypropylene crystallizes isothermally from the melt, it was found that both biodegradable plastic additives used decreases the size of the spherulites and increases their densities per unit volume. The incorporation of the Biosphere within the polypropylene matrix raises the crystallization temperature while the existence of D2W within the matrix delays the crystallization process. The addition of 2 wt% of Biosphere allows polypropylene to crystallize at about 13°C higher than neat polypropylene. It has been found that the addition of the biosphere increases Young’s modulus, while decreases the yield strength, the elongation at break, and the impact strength. On the other hand, D2W as an oxidative biodegradable plastic additive increases the elongation at break and the impact strength while decreases the yield strength and Young’s modulus.


Sign in / Sign up

Export Citation Format

Share Document