Synthesis and Properties of Degradable Copolymers Com- posed of Poly（E-caprolactone） and 3,4-Dihydroxycinnamic Acid

摘要

Photoreactive and degradable hyperbranched (HB) copolymers with various 3,4-dihydroxycinnamic acid (DHCA) compositions, poly(e-caprolactone)-co-poly(3,4-dihydroxycinnamic acid) (PCL-co-PDHCA), were ob- tained by thermal melt-polycondensation of PCL and DHCA. The HB structures and the branching degree (BD) of the PCL-co-PDHCA copolymers were confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H NMR). The melting points (Tm) of the PCL-co-PDHCA copolymers changed depending on the PCL and DHCA composition by differential scanning calorimetry (DSC) measurements. Wide angle X-ray dif- fraction (WXRD) analysis showed semi-crystalline of the PCL and PCL-co-PDHCA polymers. The PCL-co-PDHCA copolymers showed good photoreactivities and fluorescent properties. Crosslinking of the cin- namoyl groups in the copolymers caused by UV irradiation affected the thermal stability and wettability slightly. Moreover, the hydrolysis experiments revealed that copolyrners are facile degradable.