XRD studies of polyurethane elastomers based on chitin/1,4-butane diol blends

Chitin based polyurethane elastomers (PUEs) were synthesized by step growth polymerization techniques using poly (epsilon-caprolactone) (PCL), 4,4'-diphenylmethane diisocyanate (MDI) and blends of chitin and 1,4-butanne diol (BDO). The conventional spectroscopic characterization of the samples with FT-IR, H-1 NMR and C-13 NMR were in accordance with proposed PUEs structure. The crystalline behavior of the synthesized polymers were investigated by X-ray diffraction (XRD). differential scanning calorimetery (DSC) optical microscopic technique and loss tangent curves (tan 6 peaks). Results showed that crystallinity of the synthesized PUEs samples was affected by varying the chitin contents used as chain extender. The contents of chitin favors the formation of more ordered structure, as higher peak intensities were obtained from the PU extended with chitin than 1,4-butane diol (BDO). X-ray diffraction experiments results correlates with optical microscopy findings. The higher Delta H value; 41.57 (J g(-1)) was found in the samples extended with chitin than BDO (31.32 J g(-1)). (C) 2008 Elsevier Ltd. All rights reserved