POLYMERS Vol.64 No.8
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Memory of Shape
COVER STORY: Highlight Reviews
Bio-Based Films Showing Double Shape-Memories by Thermal and Photonic Stimuli Tatsuo KANEKO
<Abstract> Multi shape memory is an important topic in the field of shape-memory actuator. Polyesters having photofunctional biomolecules, cinnamoyls, in the main chains were prepared. The films of the polyesters showed multi-shape memory by combining two functions; 1) Photomechanics, 2) thermal shape memory based on physical cross-linking formed by entanglement of hyper-branching polymers.
Keywords: Cinnamoyl / Photomechanics / Shape Memory / Bioplastics / Isomerization / Polycondensation
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Development of High Performance Shape Memory Composite Material Hisaaki TOBUSHI
<Abstract> Although the property to recover the original shape from the deformed shape by heating is similar for shape memory alloy and shape memory polymer, the dependence of elastic modulus and yield stress on temperature is quite the opposite for both materials. If the composite material composed of materials having different properties is developed, the novel functional property, which is not obtained by a simple substance, can be used. The development of the high performance shape memory composite material composed of shape memory alloy and shape memory polymer having different phase transformation temperatures is explained.
Keywords: Shape Memory Alloy / Shape Memory Polymer / Composite / Shape Memory Composite / High Performance / Superelasticity
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Shape Memory Mechanism in Polymers Katsuhiro INOMATA
<Abstract> Shape memory mechanism of polymeric materials is not a special function, but can be simply explained with considering thermo-plastic and elastic properties. Original permanent shape is defined by cross-linking of polymer chains like elastic rubber. After deformation to another shape at high temperature, the temporary shape is fixed by solidification by cooling the sample like a thermo-plastic polymer. Instead of thermal transition, hardening-softening transition can also be achieved by solvent swelling and drying process. In this sense, almost all polymers intrinsically have an ability to behave as shape memory polymers by selecting the proper shape fixing and shape recovery condition. In this review, the mechanism of shape memory behavior in polymers is described. Recent developments in shape memory polymers with complicated shape memory manners are also indicated.
Keywords: Shape Memory Polymer / Mechanical Property / Thermal Property / Thermo-Plastics / Cross-Linked Rubber
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COVER STORY: Topics and Products
Shape Stabilizing Finish “APOLLOCOT” Hiroaki HAKATA
<Abstract> Form stability processing of clothes materials is processing to give high W&W characteristics to clothes such as cotton (W&W is the index that indicates whether we can wear the cloth immediately after washing). We succeeded in the development of a 100-percent-cotton shirt material “APOLLOCOT” that has a W&W 4.0 grade level. This product has a favorable reception because we realize that we can wear it ironing-free after washing. This report introduces the resin process and the liquid ammonia process that are the key technology of “APOLLOCOT”.
Keywords: Resin / Liquid Ammonia
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Possibility for Replacing Superelastic Alloys (Shape-Memory Alloys) with Organic Compounds Satoshi TAKAMIZAWA
<Abstract> The expected thermal shape recovery nature in organosuperelastic materials is described. Shape memory effect in organosuperelastic materials can cover the vacunt recovery-force range between those of conventional shape memory polymers (SMPs) and shape memory alloys (SMAs). The organosuperelasticity can provide a novel strategy for producing alternative sort of shape-memory materials to SMPs and SMAs.
Keywords: Organosuperelasticity
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Temperature-Induced Transformable Nanoparticles Akihiko KIKUCHI, Taka-Aki ASOH
<Abstract> We describe the preparation of thermoresponsive core-corona nanoparticles with well-defined thermoresponsive corona structures. Poly(N-isopropylacrylamide) (PNIPAAm) with a polydispersity index of as much as 1.15 was prepared by atom transfer radical polymerization, followed by end group functionalization to introduce vinyl groups, thus obtaining a PNIPAAm macromonomer. The latter macromonomer was then polymerized with styrene in an aqueous organic solvent to form core-corona type nanoparticles. Both PNIPAAm chain lengths as well as the feed content led to nanoparticle diameter changes, that were a decrease with increasing PNIPAAm chain lengths and an increasing amount of feed PNIPAAm content, respectively, so that the diameter of nanoparticles were in a range of 180-1000 nm with a narrow size distribution. By using poly(butyl methacrylate) (PBMA) as the core forming materials, the shape of nanoparticles can be altered from sphere to rod by uniaxial extention. Rod shaped nanoparticles have returned their original spherical shapes by incubating above the PBMA’s Tg values. Such characteristics may be useful for regulated interaction of nanoparticles with cells.
Keywords: Poly(N-isopropylacrylamide) / Core-Corona Type Nanoparticles / Atom Transfer Radical Polymerization / Suspension Polymerization / Transformable Nanoparticles / Glass Transition Temperature
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Polymer Science and I: A Personal Account
Be a Treasure Hunter Sadaki SAMITSU
<Abstract> “Research activity is like treasure hunting”, is a quote from my supervisor that was the starting point of my research career. Development of new materials for practical applications is really a tough challenge. This is a short story of how I gained scientific knowledge and learned new research techniques, and an account of what I want to become in the future.
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Front-Line Polymer Science
Polymer Synthesis using CO2 as a Co-monomer Kyoko NOZAKI, Ryo NAKANO
<Abstract> Carbon dioxide has attracted broad interest as a C1 feedstock, due to its abundance in nature, low price, low-toxicity, and renewability. In polymer synthesis, the use of carbon dioxide as a building block of polymeric materials has been investigated since the early 70s. To exploit the prospective nature of carbon dioxide as a C1 resource, availability of a cheap and mass-produced co-monomer is essential for further industrial application. We review recent efforts to utilize carbon dioxide as a co-monomer for polymerization. Along with a few industrialized copolymers such as urea resins and polycarbonates, various copolymers made from carbon dioxide are summarized.
Keywords: Carbon Dioxide / Copolymerization
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