Shape Memory Polyesters

Dihydrocarvone can be epoxidized to give the corresponding epoxylactone (72). This compound can be used as a multifunctional monomer and as a crosslinking agent in ring opening metathesis polymerization. 

The homopolymerization of the epoxylactone using diethylzinc and tin(ll) 2-ethylhexanoate as catalysts yields only low molecular weight oligomers with an number average molecular weight of less than 2.5 kgmol. However, the copolymeiization with -caprolactone results in flexible crosslinked materials in a one-step synthesis. These copolymers exhibit a near perfect shape memory property, even after repeated bending (72). 

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Lowe JR, Tolman WB, Hillmyer MA (2009) Oxidized thhydrocarvone as a renewable multifunctional monomer for the synthesis of shape memory polyesters. Biomacromolecules 10 2003-2008... 

New elastic fibers like comfort Lycra, XLA, polyester-based bicomponent fiber, and shape memory fibers provide a fit that is more relaxed than traditional spandex (Figure 3.10). Wearers feel less compressive force fighting against their movements in garments made of these fibers and blends than when wearing the same garment made with lower stretch textured yams and common spandex. 

Peng, Y, Zhang, S., Zhang, L., Guo, J., and Xu, Y. 2011. Synthesis and characterization of hydrophilic polyester-PEO networks with shape-memory properties. 

Zhou J, Schmidt AM, Ritter H (2010) Biocomponent transparent polyester networks with shape memory effect. Macromolecules 43 939... 

Abstract This chapter describes vegetable oil-based polymer nanocomposites. It deals with the importance, comparison with conventional composites, classification, materials and methods, characterisation, properties and applications of vegetable oil-based polymer nanocomposites. The chapter also includes a short review of polymer nanocomposites of polyester, polyurethanes and epoxies based on different vegetable oils and nanomaterials. The chapter shows that the formation of suitable vegetable oil-based polymer nanocomposite can be considered to be a means of enhancing many of the desirable properties of such polymers or of obtaining materials with an intrinsically new set of properties which will extend their utility in a variety of advanced applications. Vegetable oil-based shape memory hyperbranched polyurethane nanocomposites can be sited as an exampie of such advanced products. 

Shape Memory Systems with Biodegradable Polyesters... 

I 6 Shape Memory Systems with Biodegradable Polyesters 6.2.2.2 Cross-linked... 

Ishida, K., Hortensius, R., Luo, X., and Mather, P.T. (2012) Soft bacterial polyester-based shape memory nanocomposites featuring reconfigurable nanostructure. J. Polym. ScL, Part B Polym Phys., 50 (6), 387-393. 

Traditionally, chemical catalysts have been used to perform several reactions. By replacing the chemical catalysts with enzymes, final products can proceed in a controlled manner. Enzymatic reactions can be used to upgrade cheap and saturated fats or to add value to commercial fats and oils. Vegetable oil-based polyurethane, polyester, polyether and polyolefin are the four most important classes of polymers, many of which have excellent biocompatibilities and unique properties including shape memory. Many researchers have investigated lipase-catalyzed reactions as an alternative to green processes and as a way to improve the physical properties of final products (Miao et al., 2013). 

Figure 7.10 (a) Shape memory bile add-based polyester and (b) poly(D,L-LA-6/ocfc-NBE) bearing photocross-linkable cinnamate side chains. 

Cao, Q. and P.S. Liu (2006), Structure and mechanical properties of shape memory polyurethane based on hyperbranched polyesters. Polymer Bulletin, 57(6) pp. 889-899. 

Development of Polyester Type Shape Memory Polymer and Its Application to Composite Material... 

Development of Polyester Type Shape Memory Polymer. 

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