Previous studies have shown elastomer/methacrylate monomer formulations to have good strength; however, water uptake was high
and they also suffered from oxidation. This study has looked at the use of three different butyl
elastomers, well known for their oxidation resistance, butyl (PB), chlorobutyl (PCB)
and bromobutyl (PBB). The tensile
and water uptake properties of the three
elastomers gelled with ethyl hexyl methacrylate containing 1%ethylene glycol dimethacrylate
and 1%lauryl peroxide (5+ formulation from previous studies) were studied. Water uptake of the pure
elastomers was also measured. Tensile strengths were low (PCB5+=3.09±0.12MPa
and PBB5+=3.90±0.36MPa); however, elongation to break values were high (PCB5+=797±17%
and PBB5+=599±13%). Water uptake was high
and protracted with none of the formulations reaching equilibrium. The PCB5+ had the highest uptake (
![](/images/glyphs/BQ1.GIF)
6%at 203 days) with that for PBB5+
and PB5+ at a similar level (
![](/images/glyphs/BQ1.GIF)
4%at 203 days). None of the materials showed any sign of oxidation. The PBB proved to be the most suitable of the three
elastomers for further development in
soft lining formulations.