Poly step-growth syntheses

HydrophobicaHy Modified, Ethoxylated Urethane. HEUR associative thickeners are in effect poly(oxyethylene) polymers that contain terminal hydrophobe units (66). They can be synthesized via esterification with monoacids, tosylation reactions, or direct reaction with monoisocyanates. There are problems associated with aH of the methods of synthesis. The general commercial procedure for their synthesis is by a step-growth addition of... 

At about die same time, die application of the Suzuki coupling, the crosscoupling of boronic acids widi aryl-alkenyl halides in die presence of a base and a catalytic amount of palladium catalyst (Scheme 9.12),16 for step-growth polymerization also appeared. Schliiter et al. reported die synthesis of soluble poly(para-phenylene)s by using the Suzuki coupling condition in 1989 (Scheme 9.13).17 Because aryl-alkenyl boronic acids are readily available and moisture stable, the Suzuki coupling became one of die most commonly used mediods for die synthesis of a variety of polymers.18... 

Rojas R, Harris NK, Piotrowska K, Kohn J (2009) Evaluation of automated synthesis for chain and step-growth polymerizations can robots replace the chemists J Poly Sd Part A Polym Chem 47 48-58... 

Step-growth polymerization, 22, 24-25, 23, 84-86, 86,90-92,114-115, 261 compared with chain-growth polymerization, 88-89, 88-89 interfacial polymerization, 91-92 laboratory activities on synthesis of nylon, 228-230 synthesis of polyesters in the melt, 231-233 synthesis of polyurethane foam, 234-237 molar mass and, 86, 86 polycondensation of poly ethylene terephthalate), 90-91 polymers produced by, 86 types of monomers for, 90 Stereochemistry, 28, 37-39,41-42, 70 tacticity, 103-105 Stereoisomers, 41 Stereoregularity, 70 Stiffness, 142, 261 Strain, 142-143, 261 Strength... 

Not all copolymers which are produced by step-growth processes are random in nature. Block copolymers are also of major interest. An example of the synthesis of elastic polyurethane fibers was given in Section 1.5.4. Block and graft copolymers of polysiloxane-poly(alkylenc ethers) with segments like5-9 are used as surfactants in the production of polyurethane foams with uniform cell sizes. 

Throughout this chapter, the examples of polymerizations in compressed CO2 have been primarily for chain growth polymerization processes. However, step-growth methods represent an area of new interest for SCFs. Initial experiments in this area include the synthesis of aromatic polyesters such as poly(ethylene terephthalate) (PET) in SCCO2 as illustrated in Scheme 4.5-9 [144]. An advan-... 

A. Ben-Haida, H. M. Colquhoun, P. Hodge, and D. J. Williams. Synthesis of a catechol-based poly(ether ether ketone) ("o-PEEK") by classical step-growth polymerization and by entropically driven ring-opening polymerization of macrocyclic oligomers. Macromolecules, 39(19) 6467-6472, September 2006. 

The synthesis and the modification techniques concerning PES have been reviewed by Kricheldorf. Poly(ethersulfone)s can be obtained either by a conventional step-growth polycondensation, or by a chain-growth polycondensation, which is in fact a living polycondensation. ... 

Wang S, McGrath JE. Synthesis of poly(arylene ether)s. In Rogers M, Long TE, editors. Synthetic methods in step-growth polymers. New York Wiley 2003. p. 327-74 [chapter 6]. 

The Michael addition is a very efficient reaction that has been widely applied for dendrimer synthesis due to a small amount of side reactions and mild reaction conditions, poly (amido amine) (PAMAM) or poly(propylene imine) (PPI) dendrimers are two well-known examples that rely on the Michael addition. Long et al. reviewed the synthetic approaches to linear, cross-linked, and branched polymers via step-growth Michael polyaddition.Thermally stable, high-Tg poly... 

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