Polycarbonate urethane urea

Different types of biostable PURs have been used in heart valve components, including polyether urethanes (PEUs), polyether urethane ureas (PEUUs), polycarbonate urethane (PCUs), polycarbonate urethane ureas (PCUUs), polycarbonate-based materials that contain polyhedral oligomeric silsequioxane nanoparticles (POSS) (Ghanbari et al., 2010 Kidane et al 2009b), and those that contain polysiloxane soft segments (Bezuidenhout et al 2015). 

Oligomeric carbodiimides are useful stabilizers for ester based polymers, such as polyesters, polyester based polyurethanes, polyether based polyurethanes, polyether based poly(urethane ureas) and polycarbonates. The scavenging of carboxyl end groups or carboxyl groups, generated in the hydrolysis of polyesters, with carbodiimide prevents hydrolysis of the polymers caused by the catalytic effect of the carboxyl groups. Neumann... 

Poly(acrylate-ien-urethane-urea), 256-260 Poly (acrylic acid-ABc-vinyl alcohol), 264 Polyacrylonitrile, 3 Polybutadiene, 3, 273, 310 Poly(butadiene-co-methacrylic acid), 165 Poly(butadiene- -styrene), 79ff Poly(butadiene-ipn-styrene), 239ff Poly(n-butyl acrylate-ipn-methyl methacrylate), 267 Polycarbonate, 42... 

The principal kinds of thermoplastic resins include (1) acrylonitrile-butadiene-styrene (ABS) resins (2) acetals (3) acrylics (4) cellulosics (5) chlorinated polyelliers (6) fluorocarbons, sucli as polytelra-fluorclliy lene (TFE), polychlorotrifluoroethylene (CTFE), and fluorinated ethylene propylene (FEP) (7) nylons (polyamides) (8) polycarbonates (9) poly elliylenes (including copolymers) (10) polypropylene (including copolymers) ( ll) polystyrenes and (12) vinyls (polyvinyl chloride). The principal kinds of thermosetting resins include (1) alkyds (2) allylics (3) die aminos (melamine and urea) (4) epoxies (5) phenolics (6) polyesters (7) silicones and (8) urethanes,... 

The cyclic diether, 1,3-dioxolane, is recommended by Ferro Corporation as a more benign solvent substitute for chlorinated organic solvents, such as methylene chloride, 1,2-dichloroethane, and 1,1,1-trichloroethane, and for ketones, such as methyl ethyl ketone (MEK). This ethylene glycol-based ether is a suitable solvent under neutral and basic conditions in several major-use areas. It is a powerful solvent for softening and dissolving polymers made from polar monomers, for example, polycarbonates, acrylates, cellulosics urethanes, phenoUcs, nitriles, urea-formaldehydes, and alkyds, as well as polyesters, vinyl epoxys, and halogen-containing polymers. As a reaction solvent it is added as a component to a special quaternary ammonium or phosphonium salt solution for preparation of a vesicular phenoxy resin. Other beneficial uses for the solvent dioxolane, include ... 

Scheme 5.9 Insertion reaction of an organomagnesium tetramethylene urea in a polycarbonate with the formation of two urethane groups.

Part 2 includes chapters on specific classes of cyclic monomers and their polymerization mechanisms and kinetics, their main (co)polymer architectures and related products, as well as current and future applications. Hence, siloxane-con-taining and sulfur-nitrogen-phosphorus-containing polymers are described in Chapters 3 and 4, respectively, while the polymerization of cyclic depsipeptides, ureas and urethanes, of polyethers and polyoxazolines, and of polyamides are detailed in Chapters 5, 6 and 7, respectively. Chapters 9, 10, 11 and 12 include details of polyesters prepared from either P-lactones, from dilactones, from larger lactones and from polycarbonates, while the polymerization of cycloalkanes is described in Chapter 13. It should be noted that, slightly out of place . Chapter 8 covers the subject of ring-opening metathesis polymerizahon. 

COj is an abundant, nontoxic, nonflammable, easily available, and renewable carbon source. Using CO2 as a carbon source to produce useful chemicals benefits the sustainable development of our society. In addition, sc conditions can enhance the reactivity of CO2 [39]. In recent years, SCCO2 and SCCO2-IL systems have gained a growing interest since CO2 can play a dual role as both the reactant and solvent. Many valuable substances has been obtained, such as dimethyl carbonate, cyclic carbonate, polycarbonates, N,N -disubstituted ureas, urethanes, formic acid, other organic acids, and others [40]. 

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