New approaches to the melt stabilization of polyolefins

Voigt, Wolfgang; Todesco, R. V.

doi:10.1016/s0141-3910(02)00089-7

Cited by 38 publications

(24 citation statements)

References 3 publications

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“…54 Phosphites effectively decompose hydroperoxides: 55 Phosphites act as secondary antioxidants: they reduce the hydroperoxides formed from peroxy radicals to the corresponding alcohol by a redox reaction, being simultaneously oxidized to the corresponding phosphate. 56 Combined HAS and phosphite in one molecule were synthesized and they had even better performance in decomposition of hydroperoxides. 57 This combination also improved hydrolytical stability of phosphites.…”

Section: Peroxide and Hydroperoxide Decompositionmentioning

confidence: 99%

“…Phenolic antioxidants scavenge alkoxy and peroxy radicals. 56 By donating a hydrogen radical they neutralize these kinds of radical species which are either formed through the harsh processing conditions in the presence of oxygen or by the cleavage of hydroperoxides. 53 Phenolic antioxidants protect polymers during processing as well as in the end application as long-term thermal stabilizers.…”

Section: Peroxide and Hydroperoxide Decompositionmentioning

confidence: 99%

“…53 Phenolic antioxidants protect polymers during processing as well as in the end application as long-term thermal stabilizers. 56 It is known that some PVC stabilizers, including sulfur-containing organotins and maleate type organotins, can also decompose hydroperoxides. 58,59 Volatile peroxides are generated during the oxidation of polypropylene.…”

Section: Peroxide and Hydroperoxide Decompositionmentioning

confidence: 99%

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Mechanisms of Uv Stabilization

2015

Handbook of UV Degradation and Stabilization

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Section: Peroxide and Hydroperoxide Decompositionmentioning

confidence: 99%

Section: Peroxide and Hydroperoxide Decompositionmentioning

confidence: 99%

Section: Peroxide and Hydroperoxide Decompositionmentioning

confidence: 99%

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Mechanisms of Uv Stabilization

2015

Handbook of UV Degradation and Stabilization

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“…However, ZnO adds about 10% more opacity relative to CaSt. This physical effect may lead to apparently improved color stability [27].…”

Section: Acid Scavengersmentioning

confidence: 99%

“…Preliminary studies indicated that some phenolic antioxidants (AOs) induce more discoloration than others because of variations in the structure of the transformation products [27]. The next section explores the performance of the best candidate color suppressant (DPE) in combination with a range of phenolic AOs and ZnSt.…”

Section: Color Suppression Of Dpe With Other Antioxidantsmentioning

confidence: 99%

Color inhibition of phenolic antioxidants in Ziegler‐Natta polyethylene. I. In‐situ polymer studies

Allen

Liauw

Reyes

et al. 2009

Vinyl Additive Technology

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Although the level of transition-metal catalyst residues in polyethylene (PE) has been drastically reduced over the years, they can still give rise to discoloration, particularly when associated with other additives such as antioxidants. This first of this series of papers screens a variety of candidate color suppressants featuring a range of functional groups, including alcohols, amine/ sulfur compounds, and acid-containing species. These candidate color suppressants were melt-blended into a Ziegler-Natta linear low-density PE in combination with 2,2 0 -isobutylidenebis(4,6-dimethylphenol) (a highly discoloring hindered bisphenol antioxidant) and zinc stearate antacid. Yellowness index measurements made after multiple extruder passes indicated that dipentaerythritol (DPE) and triisopropylamine (TIPA) gave good color inhibition and, in some cases, outperformed established phosphites. The DPE and TIPA were found (via melt flow rate measurement) not to affect melt stability, and hydroperoxide determination revealed that DPE had no peroxide decomposition activity. The latter results indicate that the color-suppression mechanism of DPE and TIPA is different from that associated with phosphites.

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Antioxidants, Polymers

Kröhnke

Zäh

2022

Kirk-Othmer Encyclopedia of Chemical Technology

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Organic matter is subject to decomposition, particularly through reaction with oxygen. This leads to several reactive secondary products such as hydroperoxides and peroxy and alkoxy radicals. Antioxidants are used to slow down oxidative degradation by reacting with these reactive intermediates. On the one hand, this article explains the mechanism of the oxidation of polymers and, on the other hand, describes suited antioxidants and their influence on the stabilization of polymers during their processing in the melt and during their service life. Suitable antioxidants, including combinations of antioxidants, which act as free‐radical scavengers (primary antioxidants) and hydroperoxide or peroxide scavengers (secondary antioxidants), are explained. Traditional commercial antioxidants still play a role when used in industrially manufactured polymers. Moreover, the stabilization of polymer recyclates against oxidative degradation is gaining in importance. Furthermore, in recent years, unconventional antioxidants of natural origin have also increasingly come into focus. Methods for the analytical determination of antioxidants in polymeric substrates are also described, with which the consumption and effectiveness of these products can be examined.

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New approaches to the melt stabilization of polyolefins

Cited by 38 publications

References 3 publications

Mechanisms of Uv Stabilization

Mechanisms of Uv Stabilization

Color inhibition of phenolic antioxidants in Ziegler‐Natta polyethylene. I. In‐situ polymer studies

Antioxidants, Polymers

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