Triple-shape memory properties of polyurethane/polylactide-polytetramethylene ether blends

A facile method to prepare triple-shape memory polymers was developed by blending polyurethane and polylactide-polytetramethylene with well-separated glass transition temperatures. The thermal properties of the blends were characterized using modulated differential scanning calorimetry and differential scanning calorimetry. Field emission scanning electron microscopy, Fourier transform infrared spectroscopy and wide-angle X-ray diffraction were used to characterize the microstructures and crystal structures of the blends. The mechanical properties were also evaluated. The versatile triple-shape memory effect and quantitative shape memory response were evaluated by consecutive thermal mechanical experiments based on a two-step programming process and subsequent progressive thermal recovery. The results show that the blends have phase-separated microstructures resulting in an ability to fix two temporary shapes independently and can recover to their original shapes sequentially. The blends have excellent triple-shape memory properties and may have some applications in multi-shape coatings, adhesives, films and temperature sensing or actuating elements. (c) 2015 Society of Chemical Industry