Design of Triple-Shape Memory Polyurethane with Photo-cross-linking of Cinnamon Groups

Abstract

A triple-shape memory polyurethane (TSMPU) with poly(ε-caprolactone) -diols (PCL-diols) as the soft segments and diphenyl methane diisocyanate (MDI), N,N-bis (2-hydroxyethyl) cinnamamide (BHECA) as the hard segments was synthesized via simple photo-crosslinking of cinnamon groups irradiated under λ > 280 nm ultraviolet (UV) light. Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance ( 1 H-NMR) and ultraviolet-visible absorption spectrum (UV−vis) confirmed the chemical structure of the material. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) results demonstrated that the photocrosslinked polymer possessed two transition temperatures, one is due to the melting point of the soft segment PCL-diols, and the other is due to the glass transition temperature. All these contributed to the cross-linked structure of the hard segments and resulted in an excellent triple-shape memory effect. Alamar blue assay showed that the material has good non-cytotoxicity and can be potentially used in biomaterial devices.

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

“…Recently, multiple‐shape (triple‐ or quadruple‐shape) memory polymers, which can sequentially recover to their original (permanent) shapes from two or three previously programmed temporary shapes, have attracted more and more attention . Compared with conventional dual‐SMPs, multiple‐SMPs have at least two temporary shapes, providing more flexible applications such as in intelligent medical devices, assembling systems and minimally invasive surgery …”

A novel shape memory poly(ε-caprolactone) network via UV-triggered thiol-ene reaction

“…Figure shows the variation of storage modulus ( E ′) and tan δ as a function of temperature for three SiO 2 ‐SMPs. E ’ presented higher values as increasing the M w of PCL, and this could be due to the higher degree of crystallinity . It is evident all samples displayed a dramatic decrease of E ’ around their melting regions, with the presence of two plateaus.…”

Biocompound-Based Multiple Shape Memory Polymers Reinforced by Photo-Cross-Linking

“…13 Thermo-induced shape memory effect is more common, and most of these polymers have a permanent shape provided by cross-linked phases, and a temporary shape fixed by frozen molecular chains during vitrification or crystallization by lowing below a transition temperature (T trans ). The cross-linked phases include chemical and physical cross-linking, such as crystalline domains [14][15][16] or strong supramolecular interactions. 17 The transition temperatures include glass transition temperature and melting point.…”

“…irradiation with UV light (λ = 365 nm), the absorption intensity of C=C stretching vibration at 1636 cm -1 of MCE decreases gradually due to the [2+2] cycloaddition of the C=C double bond 14,42,43. The degree of photo cross-linking may be calculated by normalizing the peak height at 1636 cm -1 in reference to the peak height of C=O at 1730 cm -1 using the following equation: is the degree of cross-linking, (I 1636 /I 1730 ) 0 and (I 1636 /I 1730 ) t are the relative intensity of the C=C bond before and after irradiation.…”