Lodz University of Technology Poland Radiation methods of

Lodz University of Technology, Poland Radiation methods of polymer modification: Hybride crosslinking of butadiene – acrylonitrile rubber MS. KATARZYNA BANDZIERZ PROF. DARIUSZ BIELIŃSKI

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. Ion izin g ra diat ion - ENE RGY Secondary electron

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. Ion izin g ra diat ion - ENE RGY Secondary electron Radiation engineering – involves practical application of chemical reactions (and biological and physcical processes) initiated with ioniznig radiation.

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

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

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

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”

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

Results – crosslinking of nitrile rubber Density of network as a function of ionizing radiation dose Network density [mol/cm 3] radiation crosslinking radiation and thermal crosslinking 5 E-04 4 E-04 3 E-04 Network density of sample crosslinked solely thermally: 2 E-04 1 E-04 0 E+00 0 50 100 150 200 250 300 350 2, 2 ∙ 10 -4 [mol/cm 3] Dose [k. Gy] material composition: NBR (100 phr), MBTS (1, 5 phr), S 8 (2 phr), Zn. O (5 phr), stearic acid (1 phr), silica Aerosil A 380 (40 phr)

Results – mechanical properties of composite 200 k. Gy 250 k. Gy material composition: NBR (100 phr), MBTS (1, 5 phr), S 8 (2 phr), Zn. O (5 phr), stearic acid (1 phr), silica Aerosil A 380 (40 phr)

Results – hybride structure of crosslinks 100 k. Gy 150 k. Gy 200 k. Gy 250 k. Gy material composition: NBR (100 phr), MBTS (1, 5 phr), S 8 (2 phr), Zn. O (5 phr), stearic acid (1 phr), silica Aerosil A 380 (40 phr)

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

THANK YOU FOR YOUR ATTENTION Contact: katarzyna. bandzierz@gmail. com MS. Katarzyna Bandzierz Institute of Polymer and Dye Technology Faculty of Chemistry Lodz University of Technology, Poland