1. Lodz University of Technology, Poland
Radiation methods of polymer modification: Hybride crosslinking of butadiene – acrylonitrile rubber
MS. Katarzyna Bandzierz
Prof. Dariusz Bieliński

2. Ionizing radiation
Any kind of radiation (electromagnetic, corposcular or mixture of both), which carry enough energy to break chemical bonds, separate electrons from parent atoms and molecules – cause ionization of irradiated matter.
Ionizing radiation - ENERGY
Secondary electron -

3. Ionizing radiation
Any kind of radiation (electromagnetic, corposcular or mixture of both), which carry enough energy to break chemical bonds, separate electrons from parent atoms and molecules – cause ionization of irradiated matter.
Ionizing radiation - ENERGY
Secondary electron -
Radiation engineering – involves practical application of chemical reactions (and biological and physcical processes) initiated with ioniznig radiation.

4. Electron beam (EB) as a form of ionizing radiation
Electron accelerator Elektronica ELU-6E (Institute of Applied Radiation Chemistry, Lodz University of Technology)
Operating pulpit and control cabinet of electron accelarator
Linear electron accelerator

5. Radiation modification of polymers
curing of surface layers leading to surface modification
grafting (of bulk material or surface)
chain-scissioning for recycling purposes
crosslinking of polymer materials (including heat-shrink products and hydrogels)
… and many others

6. Crosslinking of polymers
Crosslinking – process of forming bonds (crosslinks) between macromolecules’ chains, which leads to three-dimentional polymer network.
Crosslinking is fundamental and indispensable process in polymer processing !
Radiation crosslinking – scheme

7. Advantages of radiation crosslinking
Simplicity to control network density
Irradiation process can be carried out in room temperature (or either lower or higher), in air or another medium of choice (e. g. inert gas atmosphere)
Comparing to products crosslinked ‘classically’ – thermally, general improvement of properties occurs
Radiation crosslinking do not create residual stress in material (as thermal crosslinking do)
The method is fast, efficient and inexpensive, defined as “green process”

8. Author’s own research
Radiation crosslinkin of NBR with sulfur crosslinking system
Thermal crosslinking of NBR with sulfur crosslinking system
Radiation crosslinking of ‘neat’ NBR

9. Results – crosslinking of nitrile rubber
Density of network as a function of ionizing radiation dose
Network density of sample crosslinked solely thermally:
2,2 ∙ 10-4 [mol/cm3]
material composition: NBR (100 phr), MBTS (1,5 phr), S8 (2 phr), ZnO (5 phr), stearic acid (1 phr), silica Aerosil A380 (40 phr)

10. Results – mechanical properties of composite
250 kGy
200 kGy
material composition: NBR (100 phr), MBTS (1,5 phr), S8 (2 phr), ZnO (5 phr), stearic acid (1 phr), silica Aerosil A380 (40 phr)

11. Results – hybride structure of crosslinks
100 kGy kGy kGy kGy
material composition: NBR (100 phr), MBTS (1,5 phr), S8 (2 phr), ZnO (5 phr), stearic acid (1 phr), silica Aerosil A380 (40 phr)

12. Summary
Radiation modyfication of polymers (including radiation crosslinking) is highly useful method to enhance properties of polymers
The radiation modification can be run under precise control, so that properties can be ‘tailord’ for specific end-use of material
Results of autors’ research show that upon radiation crosslinking of nitrile rubber, hybride network structure can be obtained and the general properties of such material are better than of ‘classically’ – thermaly crosslinked
The process of radiation crosslinking of nitrile rubber is a promising alternative for up-till-now used method of thermal crosslinking and can be used in industry

13. Contact: katarzyna.bandzierz@gmail.com
Thank you for your attention
Contact:
MS. Katarzyna Bandzierz
Institute of Polymer and Dye Technology
Faculty of Chemistry
Lodz University of Technology, Poland