Study on shape-memory behavior of polyether-based polyurethanes. I. Influence of the hard-segment content

Lin, Jiang-Jen; Chen, L. W.

doi:10.1002/(sici)1097-4628(19980822)69:8<1563::aid-app11>3.0.co;2-w

Cited by 252 publications

(198 citation statements)

References 5 publications

(10 reference statements)

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“…Compared with shape memory metallic alloys and shape memory ceramics, SMPs possess the advantages of light weight, low cost, good processability, high shape deformability and recoverability, and tailored switch temperature [1][2][3][4][5][6][7][8][9][10]. Since the 1990s, SMPs have been increasingly developed and widely applied in smart textiles and apparels [11,12], intelligent medical devices [13][14][15], and self-deployable structures in spacecrafts [16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Shape memory effect and mechanical properties of cyanate ester-polybutadiene epoxy copolymer

et al. 2014

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A type of thermal-induced shape memory polymer was fabricated using a new epoxy resin-polybutadiene epoxy (PBEP) and bisphenol A-type cyanate ester in different mass ratios. Mechanical performance, thermal properties, and shape memory behaviors were investigated systematically. This polymer system presented good shape memory properties. The deformation recovery speed increased with the increase in the amount of PBEP. The maximum deformation recovery speed was 0.0128 s , and the minimum value was 0.0073 s −1 . The deformation recovery rate was almost 100 %.

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Section: Introductionmentioning

confidence: 99%

Shape memory effect and mechanical properties of cyanate ester-polybutadiene epoxy copolymer

et al. 2014

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“…They often contain a hard segment from methylene bis(4-phenylisocyanate) (MDI) and 1,4-butanediol. Depending on the switching segment, T trans can be either a melting temperature (2) or a glass transition temperature (3,4). Another example for shape-memory polymers with T trans being a T m are block copolymers from poly(ethylene terephthalate) and poly(ethylene oxide) (5).…”

mentioning

confidence: 99%

Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers

Mohr

Kratz

Weigel

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

752

586

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In shape-memory polymers, changes in shape are mostly induced by heating, and exceeding a specific switching temperature, T switch. If polymers cannot be warmed up by heat transfer using a hot liquid or gaseous medium, noncontact triggering will be required. In this article, the magnetically induced shape-memory effect of composites from magnetic nanoparticles and thermoplastic shapememory polymers is introduced. A polyetherurethane (TFX) and a biodegradable multiblock copolymer (PDC) with poly(p-dioxanone) as hard segment and poly( -caprolactone) as soft segment were investigated as matrix component. Nanoparticles consisting of an iron(III)oxide core in a silica matrix could be processed into both polymers. A homogeneous particle distribution in TFX could be shown. Compounds have suitable elastic and thermal properties for the shape-memory functionalization. Temporary shapes of TFX compounds were obtained by elongating at increased temperature and subsequent cooling under constant stress. Cold-drawing of PDC compounds at 25°C resulted in temporary fixation of the mechanical deformation by 50 -60%. The shape-memory effect of both composite systems could be induced by inductive heating in an alternating magnetic field (f ‫؍‬ 258 kHz; H ‫؍‬ 30 kA⅐m ؊1 ). The maximum temperatures achievable by inductive heating in a specific magnetic field depend on sample geometry and nanoparticle content. Shape recovery rates of composites resulting from magnetic triggering are comparable to those obtained by increasing the environmental temperature.nanocomposite ͉ shape-memory polymer ͉ stimuli-sensitive polymer S hape-memory polymers are able to recover their predefined original shape when exposed to an external stimulus. A prerequisite for the shape-memory effect is a preceding functionalization of the material to temporarily fix a mechanical deformation. Most shape-memory polymers are thermosensitive materials. The shape is actuated by exceeding a specific switching temperature, T switch (1). Thermoplastic shape-memory polymers have at least two separated phases, where the domains with the highest thermal transition (T perm ) stabilize the permanent shape by acting as physical netpoints. A second phase having another thermal transition T trans serves as switch. At temperatures above T trans the chain segments forming this phase are flexible and the material is highly elastic, whereas the flexibility of the chains below T trans is limited and enables the fixation of the temporary shape. T trans can either be a glass transition (T g ) or a melting temperature (T m ). Whereas T trans is the thermal transition of the switching segment phase, typically determined by differential scanning calorimetry (DSC), T switch is result of a thermomechanical test used to quantify the shape-memory effect.An important class of thermoplastic shape-memory polymers are polyurethanes. They often contain a hard segment from methylene bis(4-phenylisocyanate) (MDI) and 1,4-butanediol. Depending on the switching segment, T trans can be either a melting...

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“…The non-shape memory PU had a soft segment with glass transition temperature close to room temperature and had lower hard segment contents (HSC) than what was considered by Erden and Jana [48]. In this context, one should note that the shape recovery ratio is strongly dependent on the hard segment content [18,49]. In this work, the minor component PB was expected to add the following attributes: (1) increase the T g and increase the modulus and (2) integrate the hard domain structures by covalent bonding between PB and PU chains.…”

Section: Open Accessmentioning

confidence: 89%

“…high potential for commercialization [14][15][16][17][18][19]. The excellent properties of SMPUs are derived from the microphase-separated structures resulting from the thermodynamic incompatibility between the blocks of hard and soft segments [20].…”

Section: Open Accessmentioning

confidence: 99%

Effects of Polybenzoxazine on Shape Memory Properties of Polyurethanes with Amorphous and Crystalline Soft Segments

Jana

2014

Polymers

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This paper evaluates the role of minor component polybenzoxazine (PB) on shape-memory properties of polyurethanes (PU) with glassy and crystalline soft segments. The polymer compounds were prepared in two steps. In the first step, benzoxazine, polyurethane pre-polymer, and chain extender butanediol (BD) were mixed into a solution followed by chain-extension of the pre-polymer with BD. In the second step, benzoxazine was polymerized at 180 °C for 3 h to obtain shape memory polymer compounds. The atomic force microscopy images revealed that the PB-phase formed uniform dispersions in PU. The presence of PB-phase induced shape-memory behavior in non-shape memory PU with amorphous soft segment and significantly improved the values of shape fixity, recovery ratio, and recovery stress in shape memory polyurethane with crystalline soft segment.

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Study on shape-memory behavior of polyether-based polyurethanes. I. Influence of the hard-segment content

Cited by 252 publications

References 5 publications

Shape memory effect and mechanical properties of cyanate ester-polybutadiene epoxy copolymer

Shape memory effect and mechanical properties of cyanate ester-polybutadiene epoxy copolymer

Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers

Effects of Polybenzoxazine on Shape Memory Properties of Polyurethanes with Amorphous and Crystalline Soft Segments

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