Comparison of thermal/mechanical properties and shape memory effect of polyurethane block-copolymers with planar or bent shape of hard segment

Yang, Jae Heung; Chun, Byoung Chul; Chung, Yong‐Chan; Cho, Jae-Hwan

doi:10.1016/s0032-3861(03)00260-x

Cited by 204 publications

(119 citation statements)

References 11 publications

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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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“…2,23,24 Their shape memory behavior was also studied when replacing and varying the amount of hard segment content. 25 These studies have shown that such materials have potential for biomedical applications, since they exhibit high strain recovery, high glass/rubber modulus ratios, and their glass transition temperatures are in a favorable range for use in the human body. Additionally, the good biocompatibility of polyurethanes is well known (e.g., catheters 26 and heart valves 27 ) and has been studied for these SMPs.…”

Section: Introductionmentioning

confidence: 99%

Shape‐memory behavior of thermally stimulated polyurethane for medical applications

Baer

Wilson

Matthews

et al. 2006

J of Applied Polymer Sci

148

108

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Shape memory polymers (SMPs) have been of great interest because of their ability to be thermally actuated to recover a predetermined shape. Medical applications in clot extracting devices and stents are especially promising. We investigated the thermomechanical properties of a series of Mitsubishi SMPs for potential application as medical devices. Glass transition temperatures and moduli were measured by differential scanning calorimetry and dynamic mechanical analysis. Tensile tests were performed with 20 and 100% maximum strains, at 37 and 808C, which are respectively, body temperature and actuation temperature. Glass transitions are in a favorable range for use in the body (35-758C), with high glassy and rubbery shear moduli in the range of 800 and 2 MPa respectively. Constrained stress-strain recovery cycles showed very low hysteresis after three cycles, which is important to know for preconditioning of the material to ensure identical properties during applications. Isothermal free recovery tests showed shape recoveries above 94% for MP5510 thermoset SMP cured at different temperatures. One material exhibited a shape fixity of 99% and a shape recovery of 85% at 808C over one thermomechanical cycle. These polyurethanes appear particularly well suited for medical applications in deployment devices such as stents or clot extractors.

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“…Nota-se um pico largo, em torno de 20º, que é característico do padrão de MDI utilizado na síntese do polímero [17] , o que evidencia que o material apresenta uma estrutura semicristalina. Na Figura 3, apresenta-se a análise termogravimétrica, mostrando a curva de decomposição do polímero, que ocorre em duas etapas: a primeira etapa de 300 a 400 °C com 65% deixada pela ponta Berkovich, observa-se uma deformação plástica bem definida, sem regiões com deformação desigual, como no caso da ponta canto de cubo.…”

Section: Resultsunclassified

Aplicação de indentação instrumentada na caracterização mecânica de poliuretana derivada de óleo de mamona

et al. 2009

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Resumo: Neste trabalho são investigadas as propriedades mecânicas de poliuretana derivada do óleo de mamona, utilizando a técnica de indentação instrumentada com penetradores de geometrias piramidal e esférica. Foi analisada a influência da forma do penetrador utilizado nos ensaios de indentação instrumentada para se obter valores das propriedades mecânicas de polímero derivado de óleo de mamona. Os penetradores utilizados são de pontas piramidais dos tipos Berkovich e canto de cubo e esférico de raio igual a 150 μm em um Nanoindenter XP TM com cargas aplicadas entre 1 e 200 mN. As penetrações variam de acordo com o formato do penetrador, sendo maiores para pontas agudas. A dureza e o módulo de elasticidade foram determinados, utilizando o método de Oliver e Pharr. Verificou-se que os valores medidos para a dureza são maiores para penetradores mais agudos. Os valores obtidos com a ponta piramidal Berkovich foram de 0,14 GPa para pequenas penetrações e 0,12 GPa para maiores penetrações. Já os valores obtidos com ponta canto de cubo foram 25 a 30% maiores. Isso está relacionado com os volumes das regiões que apresentam deformações plásticas elevadas, no caso de penetradores agudos comparados com os volumes das regiões que sofrem deformações viscoelásticas. A viscosidade aparente determinada, utilizando penetrador esférico em testes de força aplicada constante, é igual a (22 ± 2) × 10 12 Pa.s. Palavras-chave: Poliuretana, viscoelasticidade, indentação instrumentada, dureza, módulo de elasticidade. Instrumented Indentation Applied to The Mechanical Characterization of Polyurethane Derived From Castor OilAbstract: The mechanical properties of polyurethane derived from castor oil, obtained by instrumented indentation technique with pyramidal and spherical indenters are reported. The influence of the indenter shape on the values of mechanical properties of the polymer was investigated. The indentations were made with pyramidal Berkovich, cube corner and a spherical indenter with radius of 150 μm in a Nanoindenter XP TM . The applied loads varied between 1 and 200 mN. The penetration depth increases for acute indenters, being higher for the cube corner tip. The hardness and elastic modulus were determined using the method of Oliver and Pharr. It was found that the measured values for hardness are higher for more acute indenters. The hardness with the pyramidal Berkovich tip was 0.14 GPa for small penetrations and 0.12 GPa for higher penetration depths. The values obtained with a cube corner tip were 25 to 30% higher. This is related to the volumes of regions with high plastic deformation in the case of acute indenters compared to the volumes of regions that present viscoelastic deformation. The apparent viscosity determined using the spherical indenter, in tests with applied constant forces, is equal to (22 ± 2) × 10 12 Pa.s.

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Comparison of thermal/mechanical properties and shape memory effect of polyurethane block-copolymers with planar or bent shape of hard segment

Cited by 204 publications

References 11 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

Shape‐memory behavior of thermally stimulated polyurethane for medical applications

Aplicação de indentação instrumentada na caracterização mecânica de poliuretana derivada de óleo de mamona

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