Synthesis and shape memory effects of Si–O–Si cross-linked hybrid polyurethanes

Xu, Jianwen; Shi, Wenfang; Pang, Wenmin

doi:10.1016/j.polymer.2005.11.035

Cited by 149 publications

(106 citation statements)

References 20 publications

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“…SMPs can be classified depending on their structures (thermosets vs. thermoplastics) and transformation temperatures (melting or glass transition temperatures) [2][3][4]. In the literature, SMPs based on common chemistries such as polyurethane (PU) [5][6][7][8][9][10][11][12][13][14][15][16][17][18], epoxy [19][20][21][22][23][24][25], polyolefin [26][27][28], as well as more exotic formulations such as partially dehydrochlorinated poly(vinyl chloride) [29], nylon/polyethylene graft copolymers [30], or poly (ether esters) [31][32][33] have been reported to show varying performances. This emphasizes the key role that polymer molecular design plays on tailoring the shape memory (SM) properties.…”

Section: Introductionmentioning

confidence: 99%

“…For certain polymers strains of up to 700% have been reported [5] compared to less than 10, 1, and 0.1% for SMA, SM ceramics, and glasses, respectively [36,37]. However, some of the major drawbacks of SMPs are their relatively low modulus, which results in small recovery stresses/forces [5,10,12,14,18,21,22,38,39] (4-10 MPa against 200-400 MPa typically or higher for SMAs [10,36]), their long response time [2,11,12,40,41] (much greater than the tens of milliseconds for SMAs of comparable size), and their seemingly low achievable number of cycles [12,14,42].…”

Section: Introductionmentioning

confidence: 99%

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Challenges of shape memory polymers: A review of the progress toward overcoming SMP's limitations

Rousseau

2008

Polymer Engineering & Sci

394

350

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Many applications ranging from biomedical to aerospace have been proposed for the use of shape memory polymers (SMPs). To optimize SMPs properties for appropriately targeting such wide-spreading application requirements, it becomes necessary to understand the structure/property relationships in SMPs. The literature was reviewed and the recent advances made in the development of SMPs were determined to establish guidelines for composition and structure considerations for designing SMPs with targeted chemical, physical, and shape memory (SM) properties. It was concluded that covalently crosslinked glassy thermosets appear to be better SMP candidates because of their intrinsically higher modulus, greater thermal and chemical stability, higher shape fixity and recovery, and possibly their longer cycle life. However, material design allows for reaching comparable or better properties for all classes of SMPs. This emphasizes that optimization of SMPs requires application-specific molecular, structural, and geometrical design. Current techniques for improving stress recovery and cycle time, which compared to shape memory alloys are the two main limitations of SMPs, are extensively discussed. Understanding the relationships between the composition and structure of an SMP and its SM properties as well as its limitations enables one to better define the development areas for high performance SMPs.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Challenges of shape memory polymers: A review of the progress toward overcoming SMP's limitations

Rousseau

2008

Polymer Engineering & Sci

394

350

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“…The list of polymers with SM properties is continuously growing; it includes physically [72][73][74][75][76][77][78] and chemically [79][80][81] cross-linked SMPUs, trans-polyisoprene-based SMPU [82,83], poly(ether ester)s like poly(ethylene oxide)/poly(ethylene terephthalate) copolymers [84][85][86], norbornyl/polyhedral oligomeric silsesquioxane (POSS) copolymers [87,88], poly(methylene-1,3-cyclopentane) and its copolymer with polyethylene [89], styrene/butadiene copolymers [90], thiol-ene/acrylate copolymers [91], polynorbornene [90], polymer networks prepared from poly(ε-caprolactone) (PCL) dimethacrylates [92,93], acrylate-based SMPs [94], (meth)acrylate networks [95,96], cross-linked polyethylene [97], epoxy-based polymers [98][99][100][101] and many others. Moreover, various polymer blends like SMPU/phenoxy resin [102], SMPU/polyvinylchloride (PVC) [103] and several others [104][105][106][107][108][109] have received attention.…”

Section: Examplesmentioning

confidence: 99%

“…In the course of cycling, the loss in stress keeping ratio was strongest for bulk specimens and improved with increasing filler contents from 10 to 30 wt%. Xu et al [79] reported the results of bending tests for Si-O-Si cross-linked organic/inorganic hybrid polyurethanes. They found that repeated cycling in air (N > 50) had no significant impact on the material's shape fixing abilities and shape recoverabilities, but cycling in water lowered the shape fixing abilities, which presumably is due to the plasticizer effect of water.…”

Section: Cycle Life Of Smps and Their Compositesmentioning

confidence: 99%

Review on the Functional Determinants and Durability of Shape Memory Polymers

Pretsch

2010

Polymers

112

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Shape memory polymers (SMP) belong to the class of stimuli-responsive materials and have generated significant research interest. Their capability to retain an imposed, temporary shape and to recover the initial, permanent shape upon exposure to an external stimulus depends on the "functional determinants", which in simplistic terms, can be divided into structural/morphological and processing/environmental factors. The primary aim of the first part of this review is to reflect the knowledge about these fundamental relationships. In a next step, recent advances in shape memory polymer composites are summarized. In contrast to earlier reviews, studies on the impairment of shape memory properties through various factors, such as aging, compression and hibernation, lubricants, UV light and thermo-mechanical cycling, are extensively reviewed. Apart from summarizing the state-of-the-art in SMP research, recent progress is commented.

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“…[1][2][3][4][5][6][7] Many structural modifications of SMPU such as flexible cross-linking method were tried to simultaneously improve both tensile mechanical and shape memory properties without a decrease in tensile strain. [8][9][10][11][12] In addition to the improvement in above properties, special effects such as electric or magnetic response, metal ion sensing, low temperature shape recovery, temperature or pH-sensing, and electric conductivity can be endowed to SMPU chains through the covalent coupling of functional molecules.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Fluorescent Shape Memory Polyurethanes Grafted with Various Dyes

Chung¹,

Choi²,

Lee³

et al. 2011

Bulletin of the Korean Chemical Society

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Shape memory polyurethane (SMPU), grafted with a fluorescent dye (Rhodamine, Mehylene violet, or Fluorescein) through an allophanate linking, was tested for the fluorescence and the shape recovery effect. The main chain of SMPU was composed of 4,4'-methylenebis(phenylisocyanate) (MDI), poly(tetramethyleneglycol) (PTMG), and 1,4-butanediol (BD), and a fluorescent dye was connected through a second MDI linked to the carbamate moiety of the main chain. Three series of SMPU, differing according to their dye content, were prepared to compare their shape recovery and fluorescence properties. In tensile mechanical property, maximum stress increased up to 350% compared to the linear SMPU, and strain remained above 2000%. Shape recovery went to as high as 97%, and remained almost same after repetitive shape recovery test cycles. Finally, the fluorescence emission of SMPU was demonstrated in the luminescence spectrum and fluorescent light emission pictures. In addition, the response of SMPU to external stimuli such as metal ions was investigated.

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Synthesis and shape memory effects of Si–O–Si cross-linked hybrid polyurethanes

Cited by 149 publications

References 20 publications

Challenges of shape memory polymers: A review of the progress toward overcoming SMP's limitations

Challenges of shape memory polymers: A review of the progress toward overcoming SMP's limitations

Review on the Functional Determinants and Durability of Shape Memory Polymers

Investigation of Fluorescent Shape Memory Polyurethanes Grafted with Various Dyes

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