1. Synthesis and properties of shape memory polyurethanes generated from schiff-base chain extender containing benzoyl and pyridyl rings
- Author
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Cheng-Lung Wu, Wen-Chin Tsen, Chih-Fu Wu, Maw-Cherng Suen, and Neng-Chiao Weng
- Subjects
Polymers and Plastics ,shape memory ,General Chemical Engineering ,Polyurethanes ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,law.invention ,chemistry.chemical_compound ,Chain (algebraic topology) ,law ,Polymer chemistry ,Materials Chemistry ,Polytetramethylene glycol ,Prepolymer ,Schiff base ,Hydrogen bond ,thermal properties ,Extender ,General Chemistry ,Shape-memory alloy ,hydrogen bonding ,021001 nanoscience & nanotechnology ,lcsh:TP1080-1185 ,0104 chemical sciences ,lcsh:Polymers and polymer manufacture ,chemistry ,0210 nano-technology - Abstract
In this study, 4,4′-diphenylmethane diisocyanate and polytetramethylene glycol were used to prepare a prepolymer; N,N′-bis(4-hydroxybenzylidene)-2,6-diaminopyridine (BHBP) was used as a chain extender; and these elements were combined to prepare a novel polyurethane, BHBP/PU. Gel permeation chromatography revealed that the molecular weight of the BHBP/PU samples increased as the BHBP content was increased. Fourier transform infrared spectroscopy demonstrated that high BHBP content facilitated strong hydrogen bonding in the samples. Differential thermogravimetry indicated that the initial decomposition temperature of BHBP/PU-3 was approximately 10 °C higher than that of BHBP/PU-1. Differential scanning calorimetry and dynamic mechanical analysis revealed that increasing the BHBP content substantially increased both the glass transition and dynamic glass transition temperatures of the BHBP/PU samples. The tensile strengths of BHBP/PU-1, BHBP/PU-2, and BHBP/PU-3 were 7.7, 10.9, and 21.6 MPa, respectively, with corresponding Young’s moduli of 0.7, 1.9, and 3.3 MPa. These results demonstrated that both the tensile strength and Young’s modulus of the BHBP/PU samples increased as the BHBP content was increased. Moreover, the BHBP/PU samples exhibited excellent shape recovery of >90%.
- Published
- 2018