Overflatemodifisering av silikongummi for å oppnå bedre adhesjon mot polare forbindelser

In this work different types of silicone rubber have been surface modified by five different methods; heat treatment, plasma treatment, acid treatment, laser treatment, and treatment with an oxidizing agent (hydrogen peroxide). The results have been evaluated by means of contact angle measurements, and in some cases with XPS (X-ray photoelectron spectroscopy). The materials were different samples of silicone rubber; some were received by NAMMO from producers; two samples were cast from liquid pre-polymers delivered by Alpina, and four types of silicone rubber were received from Momentive Performance Materials. Heat treatment was done in an oven up to 300 o C. In the acid treatment hydrochloric, sulfuric and nitric acid were used. In the laser treatment a Nd:YAG laser at 355 nm was used, and plasma treatment took place in a low pressure oxygen plasma. Heat and acid treatments resulted in, with one exception, only small changes in surface energy, even if they visually changed quite a lot. Sulfuric acid is especially destructive to silicone rubber, but still affects the surface energy only to a minor degree. One sample was not destructed by acids, and this sample also showed a significant decrease in the contact angle of water. Laser treatment resulted in only minor change in the contact angle, even if considerable physical changes in the surface were observed. Many of the samples reacted quite differently to the various treatment methods, but common for all was that the strongest increase in surface energy was obtained by plasma treatment.