Effect of Hydrophobic Comonomer Content on Assembling of Poly (N-isopropylacrylamide) and Thermal Properties

• Copolymers of N-isopropylacrylamide and octadecyl acrylate (PNO), of which the content of octadecyl acrylate (ODA) was 1.3% (PNO 1.5), 1.7% (PNO 2.0), and 3.0% (PNO 4.0), were prepared using a free radical reaction. Various assemblies were obtained depending on the concentration of PNOs and the contents of ODA. Hydrophobic interaction between ODA residues is likely to act as crosslinker. PNO 1.5 formed hydrogel at the concentration of 7%. With PNO 2.0, hydrogels were formed when the concentration was 5 and 7%. With PNO 4.0, the opaque gel was obtained when the concentration was 7%. Upon heating across the lower critical solution temperature, the hydrogels shrank but the opaque gel was broken down into a suspension. At 40 degrees C, the release degrees of fluorescein isothiocyanate-dextran were much smaller than those of release at 23 degrees C. The temperature-sensitive release is due to temperature-sensitive swelling ratio.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

NATURVETENSKAP  -- Kemi -- Polymerkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Polymer Chemistry (hsv//eng)

Keyword

N-isopropylacrylamide

hydrophobic interaction

assemblies

thermal properties

Chemistry

Kemi

Polymer chemistry

Polymerkemi

Chemistry with specialization in Polymer Chemistry

Kemi med inriktning mot polymerkemi

Publication and Content Type

ref (subject category)

art (subject category)