Grafting of thermo-sensitive N-vinylcaprolactam onto silicone rubber through the direct radiation method

• SR grafted with PNVCL for stimuli-responsiveness.
• The effects of radiation dose and monomers concentration were evaluated.
• The modified surface-responsive SR-based devices for biomedical applications.
• PNVCL onto SR has a LCST near the range of physiological temperature.

The modification of silicone rubber films (SR) was performed by radiation-induced graft polymerization of thermosensitive poly(N-vinylcaprolactam) (PNVCL) using gamma rays from a Co-60 source. The graft polymerization was obtained by a direct radiation method with doses from 5 to 70 kGy, at monomer concentrations between 5% and 70% in toluene. Grafting was confirmed by infrared, differential scanning calorimetry, thermogravimetric analysis, and swelling studies. The lower critical solution temperature (LCST) of the grafted SR was measured by swelling and differential scanning calorimetry.