Some features of phenolic inhibitor consumption in oxidized polypropylene in the presence of synergists-hydroperoxide decomposers

2003 ◽  
Vol 87 (14) ◽  
pp. 2226-2229 ◽  
Author(s):  
E. L. Shanina ◽  
G. E. Zaikov ◽  
N. A. Mukmeneva
Keyword(s):  
Phenolic Inhibitor ◽  
Oxidized Polypropylene

Chemiluminescence from oxidized polypropylene during temperature cycling

2000 ◽  
Vol 68 (2) ◽  
pp. 239-246 ◽  
Author(s):  
J. Rychlý ◽  
L. Matisová-Rychlá ◽  
D. Jurčák
Keyword(s):  
Temperature Cycling ◽  
Oxidized Polypropylene

scholarly journals Compatibilization of Polypropylene/Polyamide 6 Blend Fibers Using Photo-Oxidized Polypropylene

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 81 ◽  
Author(s):  
Francesco La Mantia ◽  
Manuela Ceraulo ◽  
Maria Mistretta ◽  
Luigi Botta ◽  
Marco Morreale
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Morphological Changes ◽  
Elongational Flow ◽  
Polyamide 6 ◽  
Flow Conditions ◽  
Polyolefin Blends ◽  
Pp Blends ◽  
Oxidized Polypropylene

The use of polyamide/polyolefin blends has gained importance and concern for years, but they also show some issues to be adequately addressed, such as the incompatibility between the two components. This is usually overcome by using suitable compatibilizers, typically based on functionalized polyolefins. However, there is only little information about the use of a degraded polyolefins to induce compatibilization. This is even truer, as far as polyamide 6/polypropylene (PA6/PP) blends are concerned. In this work, compatibilization of PA6/PP blends by using small amounts of photo-oxidized PP was investigated; furthermore, the effects due to the presence of the photo-oxidized PP were studied also in relationship to the spinning operation, where the existence of the non-isothermal elongational flow can lead to significant, further morphological changes. It was found that isotropic samples showed significant enhancements of the tensile properties upon adding the photo-oxidized PP. Under non-isothermal elongational flow conditions, the presence of the photo-oxidized PP was particularly effective in improving the mechanical properties in comparison to the uncompatibilized blend fibers. Furthermore, an important result was found: The elongational-flow processing allowed obtaining anisotropic samples where the improvements of the properties, in comparison to the isotropic samples, were similar to those achieved by using a compatibilizer.

CHEMICAL CONSTITUENTS IN WILD OAT (Avenu fatua) HULLS AND THEIR EFFECTS ON SEED GERMINATION

1982 ◽  
Vol 62 (1) ◽  
pp. 155-161 ◽  
Author(s):  
FRANK S. CHEN ◽  
JOHN M. MacTAGGART ◽  
RICHARD M. ELOFSON
Keyword(s):  
Seed Germination ◽  
Chemical Constituents ◽  
Short Chain Fatty Acids ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Nonanoic Acid ◽  
Lettuce Seed ◽  
Wild Oat ◽  
Phenolic Inhibitor ◽  
Lettuce Seed Germination

Aqueous extracts of dormant wild oat (Avena fatua L.) hulls had a weak inhibitory effect on lettuce seed germination. Both paper and thin layer chromatographic analyses of the ether-soluble acidic fraction showed the presence of phenolics and short-chain fatty acids. No abscisic acid was detected. Vanillin, protochatechualdehyde, p-coumaric acid, ferulic acid and caffeic acid were isolated from hull extracts. Vanillin was shown to be the main water-soluble phenolic inhibitor of lettuce seed germination. At a concentration higher than 6.6 × 10−3M, vanillin was found to be more inhibitory than nonanoic acid to both lettuce and wild oat germination. The concentration of phenolics in the hulls does not account for suppression of wild oat seed germination.

The influence of monomer structure on polypropylene modification in emulsion

1984 ◽  
Vol 49 (5) ◽  
pp. 1156-1166 ◽  
Author(s):  
Pavol Citovický ◽  
Darina Mikulášová ◽  
Jiří Mejzlík ◽  
Josef Majer ◽  
Viera Chrástová ◽  
...  
Keyword(s):  
Organic Liquid ◽  
Aqueous Emulsion ◽  
Heterogeneous Distribution ◽  
Solubility In Water ◽  
Chemically Modified ◽  
Heterogeneous Polymerization ◽  
Monomer Structure ◽  
Initiation Stage ◽  
Polypropylene Powder ◽  
Oxidized Polypropylene

Oxidized isotactic polypropylene powder is chemically modified by monomers of widely differing structure, the reaction being carried out at 30 °C in aqueous emulsion in the presence of a ferrous chelate as an activator. Apart from the polymer bonded to the polypropylene carrier also some homopolymer is formed simultaneously during this heterogeneous polymerization initiated by polypropylene peroxides. The mutual proportion and amount of the resulting polymers may be considerably influenced by the properties of the monomer used, such as by its partial or total solubility in water, its polarity and reactivity as well as by the substituent size. Moreover, the chelate and emulsifier type as well as the presence of organic liquid phase in the system play also an important role. The mechanistic discussion is focused to the early initiation stage of the polymerization. This period, together with the active participation of the monomer, is decisive for the formation of both polymer types produced in the system. The results obtained are in accordance with the observed heterogeneous distribution of -O-O- groups in oxidized polypropylene.

Influence of synergists: The influence of hydroperoxide decomposers on phenolic inhibitors consumption in oxidized polypropylene

2002 ◽  
Vol 85 (10) ◽  
pp. 2239-2243 ◽  
Author(s):  
E. L. Shanina ◽  
G. E. Zaikov ◽  
L. K. Fazlieva ◽  
S. V. Bukharov ◽  
N. A. Mukmeneva
Keyword(s):  
Oxidized Polypropylene

scholarly journals Luminescence from thermally oxidized polypropylene in relation to its light stability

1976 ◽  
Vol 20 (9) ◽  
pp. 2553-2556 ◽  
Author(s):  
N. S. Allen ◽  
J. Homer ◽  
J. F. McKellar
Keyword(s):  
Light Stability ◽  
Oxidized Polypropylene

Analysis of a High-Molecular-Weight Phenolic Inhibitor.

1966 ◽  
Vol 38 (9) ◽  
pp. 1221-1224 ◽  
Author(s):  
H. S. Knight ◽  
Herbert. Siegel
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Phenolic Inhibitor

The Photo-Oxidation of Polypropylene Monofilaments

1976 ◽  
Vol 46 (8) ◽  
pp. 590-599 ◽  
Author(s):  
D. J. Carlsson ◽  
F. R. S. Clark ◽  
D. M. Wiles
Keyword(s):  
Tensile Strength ◽  
Chemical Analysis ◽  
Radical Scavenging ◽  
Fiber Surface ◽  
Oxidation Products ◽  
Polypropylene Film ◽  
Elongation At Break ◽  
Photo Oxidation ◽  
Polypropylene Monofilament ◽  
Oxidized Polypropylene

The photo-oxidation of commercial, isotactic polypropylene monofilament, initiated by xenon-arc irradiation in air, leads to the initial accumulation in the fiber surface of both carbonyl species and hydroperoxide groups. These chemical changes are accompanied by a severe drop in the elongation at break. Extended irradiation leads to a substantial accumulation of these oxidation products throughout the fiber and to a loss of tensile strength. Oxidation products were identified and estimated from transmission and internal reflection in spectroscopy [∼C(O)∼ and —OH] and by chemical analysis (—OOH). Marked increases in fiber wettability were also found to accompany photo-oxidation. Distinct differences in product ratios from photo-oxidized polypropylene film and fiber samples were observed. These differences are consistent with the morphological control of the efficiency of initiation after hydroperoxide photocleavage, but are more likely to result from some radical scavenging by the unextractable phenolic additive in the commercial fiber.

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