Engineering polymers poly preparation from

Poly(2,6-dimethyl-l,4-oxyphenylene) (poly(phenylene oxide), PPG) is a material widely used as high-performance engineering plastics, thanks to its excellent chemical and physical properties, e.g., a high 7 (ca. 210°C) and mechanically tough property. PPO was first prepared from 2,6-dimethylphenol monomer using a copper/amine catalyst system. 2,6-Dimethylphenol was also polymerized via HRP catalysis to give a polymer exclusively consisting of 1,4-oxyphenylene unit, while small amounts of Mannich-base and 3,5,3, 5 -tetramethyl-4,4 -diphenoquinone units are always contained in the chemically prepared PPO. 

Miller, Neenan, et al.129,301 reported a general single-pot method (Scheme 6.5) for the preparation of poly(arylether) hyperbranched macromolecules (14 a-d), that are functionally analogous to linear poly(arylether) engineering plastics.129-3 1 The hyperbranched polymers were generated from phenolic A2B-type monomers (15 a-d), that were converted to the corresponding sodium phenoxides (16 a-d NaH, THF) and subjected to polymerization. 

Though useful polymers can be made by these reactions, their low ceiling temperatures (see p. 599) and consequent tendency to undergo facile depolymerization by an unzipping mechanism pose serious limitations. To overcome this problem the technique of end-capping or end-blocking may be used. Thus poly-oxymethylene (polyacetal), an engineering plastic, prepared from the cyclic acetal... 

Specialised polymers, which are mainly used in engineering applications in the automobile, aircraft and machinery industries, are known as engineering polymers. In this group, aliphatic polyamides are the most important and most widely used. A large number of aliphatic polyamides are obtained from vegetable oil-based products. Among these nylon 6,10, nylon 11, nylon 6,9 and poly(amido amine) are very important. One of the most important commercially used polymers, nylon 11, is obtained entirely from castor oU, whereas vegetable oil-derived components are only partly used to prepare other polymers. 

Han, Y.R., Jin, X.Y., Yang, J., Fan, Z.Y., Lu, Z.Q., Zhang, Y., Li, S.M., 2012b. Totally bioresorbable composites prepared from poly(L-lactide)-co-(trimethylene carbonate) copolymers and poly(L-lactide)-co-(glycolide) fibers as cardiovascular stent material. Polymer Engineering Science 52, 741—750. 

The strain recovery curves for (a) XPCL-1.2k/ENR, (b) XPCL-2.0k/ENR, and (c) XPCL-3.6k/ ENR blends. (Reproduced from Chang, Y.-W., Eom, J.-P, Kim, J.-G., Kim, H.-T, and Kim, D.-K. 2010. Preparation and characterization of shape memory polymer networks based on carboxylated telechelic poly( -caprolactone)/epoxidized natural rubber blends. Journal of Industrial and Engineering Chemistry 16 256-260 with permission from Elsevier.)... 

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