Spectroscopic study on water diffusion in poly(ester urethane) block copolymer matrix.
The diffusion of water in a phase-separated biodegradable poly(ester urethane) shape-memory polymer with poly(epsilon-caprolactone) (PCL) as the soft segment was investigated using time-resolved FTIR-ATR. On the basis of the band fitting and water ordering in drawn films, the broad water band in the 3800-2800 cm(-1) region was decomposed into four bands located at 3620, 3510, 3400, and 3260 cm(-1), and the first two components at 3620 and 3510 cm(-1) were assigned to the vibrations of antisymmetric and symmetric stretching of water hydrogen bonded with the C=O group of the soft segment. The other two were associated with water bonded to the urethane hard segments in the forms of N-H:O-H:O=C bridge hydrogen bond and double hydrogen bonds with two C=O groups, respectively. Furthermore, band fitting and two-dimensional correlation analyses revealed that in the diffusion process, water first diffuses into the continuous soft-rich PCL phase and then into the hard-rich urethane domains, forming double hydrogen bonds with two C=O groups prior to the bridge hydrogen bond in the form of N-H:O-H:O=C.
Wang
Wei
W
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Changchun, 130022, PR China.
Jin
Ying
Y
Su
Zhaohui
Z
D004058:Diffusion; D006860:Hydrogen Bonding; D011091:Polyesters / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
D011091:Polyesters; D011140:Polyurethanes; C081821:microthane foam; D014867:Water; C016240:polycaprolactone