The role of organic phosphite primary structure in the overall stabilization performance in polypropylene

The role of the primary P3+ functionality in the phosphite overall stabilization performance was re-evaluated. Tris(2,4-di-t-Bu-phenyl)phosphite (P-1) and its oxidation product tris(2,4-di-t-Bu-phenyl)phosphate (P-1ox) were tested both alone and in the presence of hindered phenol during processing i...

Full description

Saved in:
Bibliographic Details
Published in:Polymer testing 2017-02, Vol.57, p.126-132
Main Authors: Tochacek, Jiri, Matuska, Radek, Polacek, Petr, Stohandl, Jiri
Format: Article
Language:English
Subjects:
Action mechanism
Catalytic oxidation
Degradation
Extrusion
Formulations
Oxidation
Phosphate
Phosphite
Polypropylene
Processing
Residual stress
Stabilization
Structural stability
Studies
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The role of the primary P3+ functionality in the phosphite overall stabilization performance was re-evaluated. Tris(2,4-di-t-Bu-phenyl)phosphite (P-1) and its oxidation product tris(2,4-di-t-Bu-phenyl)phosphate (P-1ox) were tested both alone and in the presence of hindered phenol during processing in polypropylene. Efficiencies were quantified using the processing degradation index (PDI). The position of the traditional multiple extrusion curve was determined by a single parameter, describing the degree of polymer degradation. Its reciprocal allowed calculating formulations relative efficiencies. It was shown that oxidation of P3+ into P5+ is responsible for 75 % phosphite stabilization performance, regardless phosphite acts alone or in combination with phenol. If P3+ is completely oxidized, stabilizer still works. For the residual performance, the reactions of 2,4-di-t-Bu-phenyl substituents (secondary structure), are responsible. Besides processing, reactions of P3+ also contribute to the long-term stability at 150 °C. Once phosphite is oxidized, the secondary structure does not contribute to the long-term stability at all.
ISSN:0142-9418
1873-2348
DOI:10.1016/j.polymertesting.2016.11.014