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

Abstract

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. © 2015 Society of Chemical Industry

A Facile Strategy to Fabricate Multishape Memory Polymers with Controllable Mechanical Properties

“…This kind of SMPs is provided with the capability to memorize multiple temporary shapes in each shape memory cycle, and recover them consecutively upon exposure to appropriate external stimulus. This unique ability endows multi‐SMPs with obvious advantages in medical applications, intelligent actuations, as well as multishape coatings and adhesives . Due to the promising prospect, lots of researchers have been devoted to exploring the methods of fabricating multi‐SMPs.…”

“…This unique ability endows multi-SMPs with obvious advantages in medical applications, [ 1,2 ] intelligent actuations, [ 3 ] as well as multishape coatings and adhesives. [ 4,5 ] Due to the promising prospect, lots of researchers have been devoted to exploring the methods of fabricating multi-SMPs. Synthesizing polymers with more than two distinctive reversible transitions that are strongly bonded to a crosslinked structure is one of the most effi cient and widely used strategies to construct multi-SMPs.…”

Conductive shape‐memory polyurethane/multiwall carbon nanotube nanocomposite aerogels

“…The results of the DSC test show that the presence of the nanoparticles increases the crystallinity of the nanocomposite system. The crystalline phase in the shape‐memory polymers improves the recovery to the permanent shape of the sample . In other words, the MWCNT acts in the same way as the polyurethane hard segments by placing between the polymer chains.…”

“…SMPs compose of two areas; fixed areas that can maintain the permanent shape and the reversible areas, which fix the temporary shape. These areas play an essential role in determining the behavior of SMPs . In the direct heat stimulation, the SMPs subject to a temperature higher than their transition temperature.…”

Tunable triple‐shape memory composite fabricated by selective crosslinking of polycaprolactone/poly(butylene adipate‐co‐terephthalate)/bentonite

“…Compared to the traditional dual‐shape memory effect, TSME is smarter and can realize more complex recovery motion readily. TSME can be realized in polymer with either well‐separated switch temperature sections or a single broad switch temperature section . However, the amplitude of deformation is just limited around the linear elastic region in most reports, especially for those simulative works based on the constitutive equations where the high stiffness and modulus are preferred.…”