Synthesis and properties of p（NIPA-co-NVP）/clay hydrogels by radiation polymerization

In this study, hydrogels of P（NIPA-co-NVP）/clay were synthesized by γ-ray radiation. Different thermo-sensitive hydrogels were made under different experimental conditions such as dose, monomer ratio, and content of clay. X-ray diffraction shows that the layer distance between Na-clays is changed from 1.6 to 2.7 nm because Na-clay pieces can be intercalated or exfoliated by HTMAB, and that between P（NIPA-co-NVP）/clay pieces is 3.4 nm. The swelling property tests show that the LCST of P（NIPA-co-NVP） is higher than PNIPA. With the increase of NVP content, LCST is higher. As the ratio of NIPA/NVP is 95/5, hydrogel shows the best swelling property and LCST is 37℃. LCST of P（NIPA-co-NVP）/clay hydrogel is not changed, but the strength and swelling properties are better.