Monomers derivatives

The Fischer-Tropsch process can be considered as a one-carbon polymerization reaction of a monomer derived from CO. The polymerization affords a distribution of polymer molecular weights that foUows the Anderson-Shulz-Flory model. The distribution is described by a linear relationship between the logarithm of product yield vs carbon number. The objective of much of the development work on the FT synthesis has been to circumvent the theoretical distribution so as to increase the yields of gasoline range hydrocarbons. 

The heart of the petrochemical industry lies with the C2-C4 olefins, butadiene, and Ce-Cg aromatics. Chemicals and monomers derived from these intermediates are successively discussed in Chapters 7-10. 

Dithiols and dienes may react spontaneously to afford dithiols or dienes depending on the monomer dithiol ratio.221 However, the precise mechanism of radical formation is not known. More commonly, pholoinilialion or conventional radical initiators are employed. The initiation process requires formation of a radical to abstract from thiol or add to the diene then propagation can occur according to the steps shown in Scheme 7.17 until termination occurs by radical-radical reaction. Termination is usually written as involving the monomer-derived radicals. The process is remarkably tolerant of oxygen and impurities. The kinetics of the tbiol-ene photopolymerizalion have been studied by Bowman and... 

Considerable attention has been paid to aromatic hyperbranched polyesters synthesized from monomers derived from 3,5-dihydroxybenzoic acid (DBA). The thermal stability of DBA is not good enough to allow direct esterification of DBA, and therefore chemical modifications are necessary. Some aromatic monomers used for the synthesis of hyperbranched aromatic polyesters are presented in Fig. 6. 

Wooley and Bolton recently published a paper concerning hyperbranched polycarbonates obtained by polymerization of a monomer derived from 1,1,1-tris(4 -hydroxyphenyl)ethane [99]. A degradative technique was used to determine the degree of branching, which was found to be close to 0.53. Apparent molecular weights were in the range 16-82 kDa as determined by GPC relative to linear polystyrene standards. 

Lammerhofer, M., Tobler, E., Zarbl, E., Lindner, W., Svec, E, and Frechet, J. M. J. (2003). Macroporous monolithic chiral stationary phases for capillary electrochromatography new chiral monomer derived from cinchona alkaloid with enhanced enantioselectivity. Electrophoresis 24, 2986-2999. 

FIGURE 19.5 Formation of passive monomer-derived molecules. 

Ecoflex ES was commercialized by BASE in 2010 as a compound with poly(lactic acid) (PEA) (Ecovio ES see Sect. 4.2.2). Ecoflex ES is an aliphatic-aromatic polyester with a similar structure to that of Ecoflex E (see Eig. 3). However, through exchanging one of the monomers with a monomer derived from plant oil, the new Ecoflex ES is partly based on renewable resources. 

Hydrocarbon resins comprise a range of low-molecular-weight products (M < 3000) used as adhesives, hot-melt coatings, tackifying agents, inks, and additives in rubber. These include products based on monomers derived from petroleum as well as plant sources. The petroleum-derived products include polymers produced from various alkenes, isoprene, piperylene, styrene, a-methylstyrene, vinyltuolene, and dicyclopentadiene. The plant-derived products include polyterpenes obtained by the polymerization of dipentene, limonene,... 

Another major group of epoxy monomers derived from epichlorohydrin is that comprising monomers synthesized with an aromatic amine, such as aniline (DGA), para-aminophenol (TGpAP) and methylene dianiline (TGMDA) - (Table 2.1 e, f, and g). The reaction of epichlorohydrin with an alcohol is more difficult. Liquid monomers based on butanediol, neo-pentylglycol, and polypropylene oxide (molar mass in the range of 500 g mol-1), are the most common. 

The results reported demonstrate the feasibility of using monomers derived from renewable resources to build up new polymeric structures endowed with a variety of physical and mechanical properties which make them appealing for practical applications. 

Monomers derived from 10-undecenoic acid with amide functional groups have been polymerized via ADMET as well [133]. However, the low tolerance of... 

ADMET is a step growth polymerization in which all double bonds present can react in secondary metathesis events. However, olefin metathesis can be performed in a very selective manner by correct choice of the olefinic partner, and thus, the ADMET of a,co-dienes containing two different olefins (one of which has low homodimerization tendency) can lead to a head-to-tail ADMET polymerization. In this regard, terminal double bonds have been classified as Type I olefins (fast homodimerization) and acrylates as Type II (unlikely homodimerization), and it has been shown that CM reactions between Types I and II olefins take place with high CM selectivity [142], This has been applied in the ADMET of a monomer derived from 10-undecenol containing an acrylate and a terminal double bond (undec-10-en-l-yl acrylate) [143]. Thus, the ADMET of undec-10-en-l-yl acrylate in the presence of 0.5 mol% of C5 at 40°C provided a polymer with 97% of CM selectivity. The high selectivity of this reaction was used for the synthesis of block copolymers and star-shaped polymers using mono- and multifunctional acrylates as selective chain stoppers. 

Later in 1967, an attempt was made to synthesize aromatic polyimide by the thermal polycondensation of the salt monomer derived from bis(4-aminophe-nyl) ether and pyromellitic acid half diester (Eq. 3, RMsopropyl) [8]. 

Recently Russian workers reported the kinetic and thermodynamic characteristics of thermal polycondensation of the salt monomers derived from some diamines and benzophenonetetracarboxylic acid half dimethyl ester leading directly to polyimides from the viewpoint of the preparation of polyimide-based advanced composite materials (Eq. 4, R =methyl) [9-12]. 

Since the pioneering works of the Russian researchers, many attempts have been made to prepare new monomers, diamines and dianhydrides, with bulky pendent groups for novel processable polyimides. Table 5 shows some of these monomers. Monomers with small side substituents, like methyl, methoxy, tri-fluoromethyl or halogen, have not been included. In this respect, it is worth noting that many monomers derived from biphenyl, containing small side substituents, have been discovered and used in the synthesis of soluble polyimides in the last few years. They are not going to be discussed in depth in this chapter as they are considered in other parts of this book. 

Fully imidized soluble polyimides have ben prepared using monomers derived from diphenylindane and aromatic dianhydrides. Technical polymers (XU218, for instance), prepared from 1,1,3-trimethyl-diaminophenylindane and benzophenone-tetracarboxylic acid dianhydride, have been marketed over the last decade. Despite the partially aliphatic nature of polyimides containing the indane group, they show considerable retention of the thermal stability, with Tg values over 300 °C [107-110]. 

Hydroxypropanoic acid (3HPA) is under development as a future platform chemical and monomer derived from biomass. It is, at the present time, not produced on an industrial scale, either chemically or biotechnologically. 3HPA could be a key compound for the production of biomass-derived C3 intermediates, such as acrylic acid, acrylic amide and malonic acid (see Fig. 8.11). Hydrogenation of 3HPA would provide a competing procedure for the production of 1,3PD (see Section 8.2.4) that could be more economical than the DuPont and Shell processes [65]. 

Finally, dynamic peptoids, dynamic analogs of peptides and proteins, have been generated by polycondensation of complementary difunctional monomers derived... 

Hexaalkylated phenyl monomer derivatives and pentaaromatic diamines were used by O Dell [5] to prepared conjugated polymers, (IX), which were used in electroluminescent devices. In a separate investigation by O Dell [6], terpo-lymers, (X), were also prepared. 

A series of sulfobetaine monomers derived from N,N-dialkylaminophenyl-methacrylamide were synthesized using conventional pathways and polymerized to give polymers 30 (Scheme 7). The NMR spectra and solution properties were compared with those of 31 and the corresponding cationic polyelectrolytes [68,69]. 

Haaima G, Lohse A, Buchardt O, Nielsen PE. Peptide nucleic acids (PNAs) containing thymine monomers derived from chiral amino acids Hybridizahon and solubihty properties of D-lysine PNA. Angew. Chem. Int. Ed. 1996 35 1939-1942. 

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