Importance of Process Stabilisation for Long Term Properties of Polyolefins
| Title |
Importance of Process Stabilisation for Long Term Properties of Polyolefins |
| Publication year |
2009 |
| Language |
English |
| Author |
Jamtvedt, Svein H. (Norner) |
| Source |
APT’09; 8th International Conference; Katowice 03-05.November 2009 |
| Abstract |
Polyolefins are prone to degradation during compounding, converting to final products and end use. The degradation proceeds in a free radical mechanism and will finally destroy the polymer properties. Phenolic antioxidants and phosphites are important stabilisers to protect polyolefins during processing and end use. Phenolic antioxidants give good contribution to process-stability and especially long term heat stability (LTHS) of polyolefins. The main drawback is contribution to discoloration, mainly yellowing. Phosphites are known to give good process stability together with phenolic antioxidants, but very limited contribution to LTHS. High performance phosphites are contributing to a total good colour of the final product. A combination of phenolic antioxidant(s) and phosphite(s) give synergistic effect. The reason for this is that they take care of different degradation products. This paper is giving examples that some phosphites (but not all) are contributing to better LTHS, both in combination with phenolic antioxidants, but also in combination with phenolic antioxidant and thioether. |