Degradation by high energy radiation:
X-rays, gama-rays, alpha-rays & beta-rays are along the well known high energy radiations. Like UV-rays, X-rays & gama-rays are electro-magnetic radiations but their energy level is much higher than that of UV-rays. Degradation by the high energy radiations is more massive than the lower energy (UV-radiation)
When high energy radiations are so strong brutal, the polymer responds in a complex manner. It lets all sorts of things to happen from breaking its bonds or scission of its chain to cross-linking.
If the molecule is scissioned, the polymer degradation is obviously associated with a reduction in the molecular weight. On the other hand, cross linking can takes place between polymer molecules, building up the polymer networks with resultant increase in the molecular weight.
Molecular weight increase:
1. poly-amides,
2. Poly-acrylade
3. Poly-butadine,
4. Poly-ethylene,
5. Poly-propylene,
6. Poly-isoprene.
Molecular weight decrease:
1. Poly-iso-butylene,
2. Poly-metha-acrylates
3. Poly-alpha-methyl-styrene
4. Poly-tetrafluro-ethylene,
5. Cellulose.
Molecular weight increase technique:
Molecular weight decrease technique:
