β-modification of isotactic polypropylene induced by electrospun isotactic polystyrene fibers

Polymer ◽  
2019 ◽  
Vol 176 ◽  
pp. 236-243 ◽  
Author(s):  
Chi Wang ◽  
Jheng Lin Lee ◽  
Junard Landingin ◽  
Chia-Hsin Ko
2020 ◽  
pp. 59-64
Author(s):  
N. I. Kurbanova ◽  
◽  
T. M. Gulieva ◽  
N. Ya. Ischenko ◽  
◽  
...  

The effect of additives of nanofillers (NF) containing nanoparticles (NP) of copper oxide, stabilized by a polymer matrix of maleized polyethylene (MPE), obtained by the mechanochemical method, on the properties of composites based on isotactic polypropylene (PP) and high-pressure polyethylene (PE) was studied by X-ray phase (XRD) and thermogravimetric (TGA) analyzes. The enhancement of strength, deformation, and rheological parameters, as well as the thermo-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is due to the synergistic effect of the interaction of copper-containing nanoparticles with anhydride groups of MPE. It is shown that nanocomposites based on PP/PE/NF can be processed both by pressing and injection molding and extrusion, which expands the scope of its application.


1989 ◽  
Vol 54 (5) ◽  
pp. 1269-1275
Author(s):  
Miloslav Kučera ◽  
Dušan Kimmer ◽  
Karla Majerová ◽  
Zdeněk Fiala

For an effective modification of polyalkenes leading to the formation of block and/or graft copolymers, the presence of co-initiating water is absolutely necessary. We have compared two procedures used in the co-initiation of cationic reactions on polymers. Gradually supplied air moisture raises the efficiency of modification of isotactic polypropylene with poly(oxyethylene) several times, compared with a single addition of co-initiating water.


1996 ◽  
Vol 61 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Bhupendra N. Misra ◽  
G. S. Chauhan ◽  
Inderjeet Kaur

Radiation-induced graft copolymerization of vinyl acetate (VAC) and isopropenyl acetate (PAC) onto isotactic polypropylene (IPP) has been studied. The percentage of grafting was calculated for various reaction parameters, and the optimum conditions for attaining the maximum percentage of grafting were determined. Maximal achieved extents of grafting are 39% and 29% for VAC and PAC, respectively. The reactivity of the two monomers with respect to grafting is discussed.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2746
Author(s):  
Mingjin Liu ◽  
Jiaxu Luo ◽  
Jin Chen ◽  
Xueqin Gao ◽  
Qiang Fu ◽  
...  

With the development of polymer science, more attention is being paid to the longevity of polymer products. Slow crack growth (SCG), one of the most important factors that reveal the service life of the products, has been investigated widely in the past decades. Here, we manufactured an isotactic polypropylene (iPP) sample with a novel shear layer–spherulites layer alternated structure using multiflow vibration injection molding (MFVIM). However, the effect of the alternated structure on the SCG behavior has never been reported before. Surprisingly, the results showed that the resistivity of polymer to SCG can be enhanced remarkably due to the special alternated structure. Moreover, this sample shows unique slow crack propagation behavior in contrast to the sample with the same thickness of shear layer, presenting multiple microcracks in the spherulites layer, which can explain the reason of the resistivity improvement of polymer to SCG.


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