Polyolefin stabilizers

T.J. Henman (ed.), World Index of Polyolefine Stabilizers, Kogan Page, London (1982). 

Gugumus FL, "Polyolefin Stabilization From Single Stabilizers to Complex Systems", in Hamid SH (Ed) "Handbook of Polymer Degradation", Marcel Dekker, New York, 2nd Ed, 2000, Chap. 1. 

Various polyesters derived from phosphorous or phosphoric acids were prepared. Efiicient polyphosphites were synthesised in the early 196(. Polyphosphite prepared from 152 and 4,4 -isopropylidenebis(cyclohexanol) was tested as a thermal stabilizer for PC [199] or as secondary AO for radiation sterilized EPM [200]. Built-in phosphites obtained by transesterification of triallcylphosphite with 4,4 -isopro-pylidenebisphenol or 4,4 -thiobisphenol possess antioxidant properties in polyolefins. Stabilizer containing phosphite moiety 153 was prepared from tris(2-hydroxy-ethyl)isocyanate, decyl alcohol and triphenylphosphite [201]. Various phosphites were derived firom polynuclear phenols or dihydric phenols. For example, a polycondensate prepared by reaction of phosphorus trichloride with 2,5-di-rert-butylhydroquinone was tested as heat and light stabilizer for PP [202], A linear polyester with a built-in phenolic moiety was synthesised from (2,6-di-tm-butyl-4-methylphenyl)bis(6-hydroxyhexyl)phosphite and dimethyl terephthalate [203]. 

Henman TJ (1982) World list of polyolefin stabilizers. Kogan Page, London... 

Munteanu, D. Polyolefin stabilization by grafting. In Developments in Polymer Stabilisation Scott, G., Ed. Elsevier Applied Science London, 1987 Vol. 8, 179-208. 

R.L. Gray, Additives a novel non reactive HALS Boosts polyolefin stability, Plast. Eng. 1991, 47(6), 21-23. 

Ethylidene bis(4,6-di-t-butylphenol), 2,2 -Ethylidenebis(4,6-di-t-butylphenol)i EINECS 252-816-3 Phenol, 2,2 -ethylidenebis(4,6-bis(1,1-dimethyl-ethyl)- Vanox 1290, Antioxidant oxidative inhibitor for polymers process stabilizer for polyolefins stabilizer for PU and PS, Crystals mp 162-164°, Vanderbilt R.T. Co. Inc. 

This review analyzes the data on most important antioxidants for polyolefins, i. e. the data on phenols. To learn consistently the whole mechanism of polyolefin stabilization, it is not possible to consider only the facts about the kinetics of the process and relationships between the chemical structure of stabilizers and their observed efficiency. It is necessary to understand the mechanism of stabilizer action on the basis of knowledge of transformations which occur in the inhibited oxidation and of properties of resulting products. The product analyses were obtained above all from the study of models and from independent syntheses. The confirmation of results under real conditions cannot be always carried out consistently because of low concentrations, difficult isolation, and reactivity of transformation products. It is also difficult to analyze such reaction mixtures directly in a polymer6 ... 

Inhibited however, the quenching efficiency of 8 for the same tetracene 02 oxygenation In CH2CI2 solution was about three times higher (127). (Iv) Moreover, the highly colored Nl(II) chelates 79 which are comparable to B-carotene In 1-02-quenchlng efficiency [kq (79) 2.5 x lO -O sec" ], are described as excellent polyolefin stabilizers (287), while the more than 100 times less efficient IO2 quenchers 8 [R N1(II)] are not effective photo-stablllzers for polyolefins (81). (v) Furthermore,... 

Henman, T. J. 1982. World Index of Polyolefin Stabilizers Kogan Page Ltd., London, UK. 

The hypothetical life trajectory of the polyolefin product is depicted in Scheme 12.1. Its characteristic feature is the existence of the so-called induction period of degradation during which the material properties change insigruficantly and are rather similar to those in the point A in Scheme 12.1. The time lag AB (induction period) of this interval depends on the efficiency of the polyolefin stabilization. In point B, the protection effect of polymer stabilizers is ended due to the permanent initiation attack and the product properties start to deteriorate. Point C designates the failure of the product, and its further utilization becomes impossible. 

Scheme 12.5 Mechanistic look on polyolefins stabilization (Scheme 12.3 complemented)...

The above mechanisms may combine mutually, and the resulting effect on the polyolefin stability may be rather complex. 

C Neri, S Costanzi, RM Riva, R Farris, R Colombo. Mechanism of action of phosphites in polyolefin stabilization. Polymer degradation and stability. 49 65-69,1995. 

Gray RL (1990) Accelerated Testing Method for Evaluating Polyolefin Stability. In Koemer RM (ed) (leosynthetic Testing for Waste Ckmtainment Applications ASTM special technical Publication 1081. American Society for Testing and Materials (ASTM), West Conshohocken, pp 57-74... 

The amphoteric ZnO, produced in micronized form by the French process (burning of Zn vapour in an oxygen environment) entered the field of polyolefin stabilization by its UV- absorbing property, analogously to Ti02-... 

Keywords polyolefin, stabilizer, catalyst, fatty acid, nucleating, particle size, stearates, aluminium, magnesium, antioxidant, Lewis acidity, chlorine acidity, MFl, yellowness, DHT, HALS. 

Since the commercial introduction of HALS, no fundamentally new light stabilizer structures have appeared that have surpassed their efficiency in polyolefin stabilization. 

Polyolefin stabilizers Styrene Dinvyl benzene Japan 26,859(60) 1971 Tokuyama Soda... 

The main groups of additives used for polyolefin stabilization, processing, etc., are schematically presented below along with their tradenames and producers or suppliers, given in Tables l-A. 

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