The antioxidant role of α-tocopherol in polymers II. Melt stabilising effect in polypropylene

Al‐Malaika, S.; Goodwin, C. J.; Issenhuth, Sylvie; Burdick, David

doi:10.1016/s0141-3910(98)00187-6

Cited by 105 publications

(64 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As phenoxyl radicals are assumed to react very quickly by reactions (3) and (4a), this protracted antioxidant effect might be attributable to some reaction of the quinone products. However, the effect may be less pronounced than that proposed for the melt stabilisation of HDPE by [37]. For longer irradiation times (>2000 min), the carbonyl formation rate is the same for all three samples (Fig.…”

Section: Discussionmentioning

confidence: 68%

Antioxidant effectiveness of vitamin E in HDPE and tetradecane at 32°C

Mallégol

Carlsson

Deschênes

2001

Polymer Degradation and Stability

View full text Add to dashboard Cite

Vitamin E was found to be a very effective antioxidant both in a model, liquid alkane, (teradecane) and in HDPE when oxidations at close to room temperature were initiated with g-radiation. FTIR was used to follow changes in vitamin E in oxidising tetradecane and HDPE, even at very low concentrations of the antioxidant. Formation of isolated hydroperoxide groups as a direct result of the vitamin E-peroxyl radical reaction were clearly visible. Quinone products from vitamin E were formed during g-irradiation, but different quinones were formed depending on the vitamin E concentrations. Vitamin E quite effectively retarded the oxidation of HDPE during g-irradiation and so should be useful in polyethylene intended for radiation sterilisation, as packaging materials or medical devices. Crown

show abstract

Section: Discussionmentioning

confidence: 68%

Antioxidant effectiveness of vitamin E in HDPE and tetradecane at 32°C

Mallégol

Carlsson

Deschênes

2001

Polymer Degradation and Stability

View full text Add to dashboard Cite

show abstract

“…This radical participates in various reactions resulting in the formation of dihydroxydimers, spirodimers, trimer aldehydes and quinoidal products [107,108]. Most of the byproducts have additional stabilizing effect in the polymer [105] that has been confirmed also in polypropylene [106]. The efficiency of vitamin E can be further increased by the synergistic interaction of phosphite type secondary stabilizers, like The structure and characteristics of a few natural antioxidants are presented in Table 3 without any attempt of being comprehensive.…”

Section: Application In Polymersmentioning

confidence: 99%

Natural antioxidants as stabilizers for polymers

Kirschweng

Tátraaljai

Földes

et al. 2017

Polymer Degradation and Stability

157

126

View full text Add to dashboard Cite

“…Curcumin, the principal natural phenol curcuminoid of turmeric, was used also as a processing stabiliser in LLDPE and was shown to be more efficient than Irganox 1010 [7]. Further, the stabilising performance of vitamin E, both in its most bioactive form α-tocopherol [8][9][10][11] and as a mixture of the α, β, γ-tocopherols [12] were examined as natural antioxidants for protecting PE and PP against oxidation during high melt processing temperatures, and in-service, and was found to afford strong antioxidancy in both polymers, much higher than those obtained with the synthetic hindered phenols Irganox 1076 and Irganox 1010, and particularly, in the polymer melt.…”

Section: Introductionmentioning

confidence: 99%

New genre of antioxidants from renewable natural resources: Synthesis and characterisation of rosemary plant-derived antioxidants and their performance in polyolefins

Doudin

Al‐Malaika

Sheena

et al. 2016

Polymer Degradation and Stability

Self Cite

View full text Add to dashboard Cite

Several ester derivatives of rosmarinic acid (rosmarinates) were synthesised, characterised (1D and 2D NMR, UV and FTIR spectroscopy) and tested for their potential use as antioxidants derived from a renewable natural resource. The intrinsic free radical scavenging activity of the rosmarinates was assessed, initially using a modified DPPH (2, 2-diphenyl-1-picrylhydrazyl radical) method, and found to be higher than that of commercial synthetic hindered phenol antioxidants Irganox 1076 and Irganox 1010. The thermal stabilising performance of the rosmarinates in polyethylene (PE) and polypropylene (PP) was subsequently examined and compared to that of samples prepared similarly but in the presence of Irganox 1076 (in PE) and Irganox 1010 (in PP) which are typically used for polyolefin stabilisation in industrial practice. The melt stability and the long-term thermo-oxidative stability (LTTS) of processed polymers containing the antioxidants were assessed by measuring the melt flow index (MFI), melt viscosity, oxidation induction time (OIT) and long-term (accelerated) thermal ageing performance. The results show that both the melt and the thermo-oxidative stabilisation afforded by the rosmarinates, and in particular the stearyl derivative, in both PE and PP, are superior to those of Irganox 1076 and Irganox 1010, hence their potential as effective sustainable bio-based antioxidants for polymers.The rosmarinic acid used for the synthesis of the rosmarinates esters in this study was obtained from commercial rosemary extracts (AquaROX80). Furthermore, a large number of different strains of UK-grown rosemary plants (Rosmarinum officinalis) were also extracted and analysed in order to examine their antioxidant content. It was found that the carnosic and the rosmarinic acids, and to a much lesser extent the carnosol, constituted the main antioxidant components of the UK-plants, with the two acids being present at a ratio of 3:

show abstract

The antioxidant role of α-tocopherol in polymers II. Melt stabilising effect in polypropylene

Cited by 105 publications

References 14 publications

Antioxidant effectiveness of vitamin E in HDPE and tetradecane at 32°C

Antioxidant effectiveness of vitamin E in HDPE and tetradecane at 32°C

Natural antioxidants as stabilizers for polymers

New genre of antioxidants from renewable natural resources: Synthesis and characterisation of rosemary plant-derived antioxidants and their performance in polyolefins

Contact Info

Product

Resources

About