Structural origin of stress and shape recovery in shape memory starch

Coativy, Gildas; Pontoire, Bruno; Lourdin, Denis; Leroy, Éric

doi:10.1016/j.polymer.2015.09.044

Cited by 9 publications

(7 citation statements)

References 29 publications

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“… 13 A shape memory effect can also be obtained by controlling their thermo-mechanical history. 14 , 15 In our group, we have studied different compositions of extruded materials based on 2 starch botanical origins for their suitability for biomedical applications. 16 Due to its ability to crystallize during immersion in the physiological medium at 37°C, the modulus of extruded potato starch containing 20% glycerol stabilizes at about 1-2 MPa with limited swelling, which improves its durability.…”

Section: Introductionmentioning

confidence: 99%

Design, fabrication, and implantation of tube-shaped devices for the treatment of salivary duct diseases

Velásquez¹,

Chaunier²,

Guessasma³

et al. 2018

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Introduction: Starch-based materials were designed using a special extrusion die in order to obtain a tube-shaped device for application to salivary duct treatment in the field of endoscopy, i.e., sialendoscopy . Methods: Extrusion process was used to produce starch tubes. Mechanical properties of the dry tube before implantation were determined using an axial compression test. A finite element study was carried out to simulate the behavior of the hydrated tube under external axial pressure. Hydrolysis of these devices in a simulated salivary solution was studied, as well as its glycerol kinetics release. An animal short-term implantation model for salivary ducts was proposed as a feasibility study for starch tube-shaped devices. Results: A continuous production of regular and size-controlled tubes was obtained. The very small diameter obtained, less than 2 mm, corresponds to the requirement of being insertable in a human salivary duct using sialendoscopy guidewire. Finite element analysis showed that the starch tube can still support an external pressure higher than 0.2 MPa without irreversible damage. After 4 days of implantation, the host response is encouraging and the inflammatory response for this type of procedure remains normal. Conclusion: These devices were adapted to sialendoscopic guidewires and able to be implanted in the salivary ducts of pigs. If a longer lasting tube is required, the crystallinity of the starch material should be improved.

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Section: Introductionmentioning

confidence: 99%

Design, fabrication, and implantation of tube-shaped devices for the treatment of salivary duct diseases

Velásquez¹,

Chaunier²,

Guessasma³

et al. 2018

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“…PGS exhibits shape memory properties triggered by temperature which could be advantageous for low invasive surgery . After being stretched above a temperature T trans , and then, cooled below, it can keep its deformed shape below T trans and recover its initial shape by being heated above T trans when it is free of any external stress . The two pre‐requisites to obtain shape memory polymer are a permanent polymer network (cross‐linked, entangled, semi‐crystalline) and a reversible transition ( T trans ) such as glass transition or crystallization/melting of the polymer .…”

Section: Introductionmentioning

confidence: 99%

“…During shape memory creation procedure (SMCP), the polymeric network is oriented toward the direction of deformation, while crossing the reversible transitions ( T < T trans ) such as vitrification or crystallization gives the possibility to freeze the orientation. When the reversible transition is crossed again by heating ( T > T trans ), due to entropic elasticity, the orientation induced by SMCP is lost . It leads to the macroscopic shape recovery of the deformed material.…”

Section: Introductionmentioning

confidence: 99%

“…[7,8] After being stretched above a temperature T trans , and then, cooled below, it can keep its deformed shape below T trans and recover its initial shape by being heated above T trans when it is free of any external stress. [9][10][11] The two pre-requisites to obtain shape memory polymer are a permanent polymer network (cross-linked, entangled, semi-crystalline) and a reversible transition (T trans ) such as glass transition or crystallization/melting of the polymer. [6,9,10] During shape memory creation procedure (SMCP), the polymeric network is oriented toward the direction of deformation, while crossing the reversible transitions (T < T trans ) such as vitrification or crystallization gives the possibility to freeze the orientation.…”

Section: Introductionmentioning

confidence: 99%

“…When the reversible transition is crossed again by heating (T > T trans ), due to entropic elasticity, the orientation induced by SMCP is lost. [10,11] It leads to the macroscopic shape recovery of the deformed material.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis of Shape Memory Poly(glycerol sebacate)-Stearate Polymer

Coativy

Misra

Mohanty

2016

Macromol. Mater. Eng.

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The polycondensation of sebacic acid with glycerol leads to the obtaining of poly(glycerol sebacate), a tough biocompatible polymer, which exhibits shape memory properties. Due to its low glass transition and melting temperatures, the temporary shape has to be kept below room temperature. In this study, the goal is to control the melting of the polyester by adding various amount of stearic acid into the synthesis in order to store the deformed material at room temperature. The reaction is carried out with microwave heating at 180 °C until a gel is obtained. The molar ratio of sebacic acid/glycerol is fixed to 1, while the molar ratio of stearic acid/glycerol varies between 0 and 0.5. The use of a molar ratio of 0.5 leads to the obtaining of materials having a melting temperature of 29 °C able to keep their temporary shape substantially at room temperature and to recover their initial shape in water bath at 37 °C by 85%.

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Evaluation of the effect of the incorporation of poly(lactic acid) and maleic anhydride in the thermoshrinkage of films from thermoplastic starch

Montilla‐Buitrago,

Gómez‐López,

Solanilla‐Duque

et al. 2024

J of Applied Polymer Sci

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Studies on the property of shape memory in thermoplastic starch (TPS) have shown good results, making such starch a suitable candidate for use in shrink packaging. It is however necessary to evaluate blending it with other bioplastics that would improve its properties while maintaining heat shrinkage. This article thus shows the evaluation of the incorporation of different concentrations of polylactic acid (PLA) and maleic anhydride (MA) as coupling agent and their effect on shrinkage and the changes in structure of the films obtained by blown film extrusion. In most of the blends, the incorporation of PLA and MA was found to favor film shrinkage, obtaining values of up to 55% due to the fact that the interaction between TPS and PLA increased with the incorporation of MA. This was corroborated by the % of MA grafted, thermogravimetric analysis (TGA), rheological and structural tests. This allowed generating a greater molecular orientation of the films, thereby obtaining greater shrinkage. It was determined that the incorporation of PLA and % MA grafted generated good shrinkage results due to the physical and chemical crosslinking achieved in the processing of the blends in the presence of MA, enhancing their application as packaging.

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Structural origin of stress and shape recovery in shape memory starch

Cited by 9 publications

References 29 publications

Design, fabrication, and implantation of tube-shaped devices for the treatment of salivary duct diseases

Design, fabrication, and implantation of tube-shaped devices for the treatment of salivary duct diseases

Synthesis of Shape Memory Poly(glycerol sebacate)-Stearate Polymer

Evaluation of the effect of the incorporation of poly(lactic acid) and maleic anhydride in the thermoshrinkage of films from thermoplastic starch

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