Synthesis of poly (N-isopropylacrylamide)-poly(ε-caprolactone) for temperature-controlled wettability of poly(L-lactic acid)

Abstract

The biomaterials that can respond to environmental stimuli have attracted increasing attention because their applications will greatly expand the boundaries of modern medicine. In the work, poly(N-isopropylacrylamide)-poly(ε-caprolactone) (PNIPAm-PCL) with the low critical solution temperature (LCST) was synthesized by a combination of chain transfer and ring-opening method to endow poly (lactic acid) (PLLA) with the temperature-controlled wettability. The effects of PNIPAm-PCL on the thermal properties, mechanical properties, and temperature-controlled wettability were studied. At 20 wt% of PNIPAm-PCL/PLLA, the tensile strength of the material reduces slightly, but its elongation at break is enhanced significantly, which reaches 135.1%. PNIPAm-PCL/PLLA exhibits good temperature-controlled wettability. With the temperature rising from 0 to 45 °C, the water contact angle increases from 29.8° to 80.1°; conversely, it goes down, and there is a hysteresis. The material still has good stability and degradability. This work provides an example for the development of intelligent tissue engineering materials.