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.
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.
基金
The authors would like to thank the National NaturalScience Foundation of China （Nos. 51173072, 21004029, 51003042）, Research and Innovation Pro- gram for Graduate Colleges and Universities （No. CX10B_225Z） and State Key Laboratory of Molecular Engineering of Polymers （Fudan University, K2011-08） for financially supporting this research.
