Dichloro polymerization

Trilialophenols can be converted to poly(dihaloph.enylene oxide)s by a reaction that resembles radical-initiated displacement polymerization. In one procedure, either a copper or silver complex of the phenol is heated to produce a branched product (50). In another procedure, a catalytic quantity of an oxidizing agent and the dry sodium salt in dimethyl sulfoxide produces linear poly(2,6-dichloro-l,4-polyphenylene oxide) (51). The polymer can also be prepared by direct oxidation with a copper—amine catalyst, although branching in the ortho positions is indicated by chlorine analyses (52). 

Continuous polymerization in a staged series of reactors is a variation of this process (82). In one example, a mixture of chloroprene, 2,3-dichloro-l,3-butadiene, dodecyl mercaptan, and phenothiazine (15 ppm) is fed to the first of a cascade of 7 reactors together with a water solution containing disproportionated potassium abietate, potassium hydroxide, and formamidine sulfinic acid catalyst. Residence time in each reactor is 25 min at 45°C for a total conversion of 66%. Potassium ion is used in place of sodium to minimize coagulum formation. In other examples, it was judged best to feed catalyst to each reactor in the cascade (83). 

Faster addition results in some polymerization of the dichloro-ketene which darkens the precipitate. 

Unfortunately, the method is only suitable for fluorinated systems such as DFDPS. Using chloro monomers generally affords low molecular weight, because a weak base like KF or CsF is needed and DCDPS is not reactive enough under these reaction conditions. However, the activated dichloro compounds can be successfully polymerized in NMP in the presence of equimolar amounts of K2C0371. 

Dichloro monomers can also be polymerized with bisphenols in the presence of fluorides as promoting agents.78 The fluoride ions promote the displacement of the chloride sites to form more reactive fluoride sites, which react with phenolate anion to form high-molecular-weight polymers. Adding 5-10 mol % phase transfer catalysts such as A-alkyl-4-(dialkylamino)pyridium chlorides significantly increased the nucleophilicity and solubility of phenoxide anion and thus shortened the reaction time to one fifth of the uncatalyzed reaction to achieve the same molecular weight.79... 

To illustrate Eq. (6), Table 5 contains the individual results which were added to each other to obtain the solvation energy. Dichloro methane, often used in cationic polymerizations, was applied in the calculations. 

Soluble poly(l-butylperylene) (58) was prepared in very high yields by Anton and Mullen [70] who used the procedure of Taylor [71], which involves the oxidative coupling of bis-Grignard reagents with as-l,4-dichloro-2-butene as an oxidant. The products contain 4,9- and 4,10-perylenylene moieties, are fully soluble and possess average degrees of polymerization of ca. 22. 

Figure 19. Left) l,3-Dichloro-5-(l-adamantyl)benzene monomer and (Right) adamantyl-substituted poly(m-phenylene), which is shown to have a high degree of polymerization and stability, decomposing at high temperatures of around 350 °C. Taken from Ref [89] with permission.

The heats of polymerization of o-chloro-, p-chloro-, 2,5-dichloro-, and p-ethylstyrene fall in the range from 16.0 to 16.5 kcal. per mole (Tong and Kenyon s). 

Table II. Solvent Effects on the Polymerization of Dichloro-di-n-Hexylsilane...

An overview of the synthesis and characterization of a unique class of polymers with a phosphorus-nitrogen backbone Is presented, with a focus on poly(dichloro-phosphazene) as a common Intermediate for a wide variety of poly(organophosphazenes). Melt and solution polymerization techniques are Illustrated, Including the role of catalysts. The elucidation of chain structure and molecular weight by various dilute solution techniques Is considered. Factors which determine the properties of polymers derived from poly(dichlorophos-phazene) are discussed, with an emphasis on the role that the organic substituent can play In determining the final properties. 

The fullerene C o was used as the Unking agent for the synthesis of (PCHD-fc-PS)6 and (PS-fc-PCHD)6 star-block copolymers [154], The polymers were then aromatized with 2,3-dichloro-5,6-dicyano-l,4-benzoquinone, DDQ, in 1,2-dichlorobenzene to yield the corresponding copolymers containing poly(l,4-phenylene) blocks. In order to achieve high 1,4-isomer contents and to avoid termination reactions, the polymerization of CHD was conducted in toluene at 10 °C without the presence of any additive to yield products with low molecular weights. Coupling of the PCHD-fo-PSLi to C60... 

W.J. Swatos and B. Gordon, III, Polymerization of 2,2-di- -hexyloxy-a,a -dichloro-p-xylene with potassium tert-butoxide a novel route to poly(2,5-di- -hexyloxy-p-phenylene vinylene), Polym. Prepr., 31(1) 505-506, 1990. 

Moller and co-workers co-polymerized dichlorodi- -pentylsilane with either dichloro-bis-(d )-2-methylbutylsilane or dichloro-(d )-2-methylbutyl- -pentylsilane in various ratios and found a linear dependence of optical activity on mole fraction of chiral co-monomer.313 On the other hand, studies by Fujiki on co-polymers 109 formed by the copolymerization of achiral (racemic) dichlorohexyl-2-methylbutylsilane and chiral dichlorohexyl-(d )-2-methylbutylsi-lane or dichlorohexyl-(l )-2-methylbutylsilane have shown that a preferential helical screw sense can be induced by even as little as 0.6 mol% of chiral co-monomer, and that at 5 mol%, the helicity, as gauged by the gabs value, is essentially the same as that of the chiral homopolymer, as shown in Figure 40. This indicates a positive non-... 

In recent years there has been a growing interest in the use of polymeric herbicides, pesticides and drugs. Several reviews have appeared on this general area (69-71) and we earlier noted several examples of such potential behavior with poly(vinyl alcohol) modifications. These included modifications containing 6-methylthiopurine (an antileukemia drug) (55), 2,6-dichloro-benzaldehyde (a herbicide) (56), various enzymes (52,53), aspirin (analgesic)(51) and mercapto groups (46-49). 

The polymerization of styrene by trichloroacetic acid without solvent and in 1,2-dichloro-ethane and nitroethane solutions illustrates the situation where the initiator solvates ionic propagating species [Brown and Mathieson, 1958]. The kinetic order in the concentration of trichloroacetic acid increases from 1 in the highly polar nitroethane to 2 in the less polar 1,2-dichloroethane to 3 in neat styrene. 

Thermal polymerization of hexachlorocyclotriphosphazene (LXXXIII) (also referred to as phosphonitrilic chloride) yields poly(dichlorophosphazene) (LXXXIV) (IUPAC poly[nitrilo (dichloro-Ls-phosphanetriyl)] or catena-poly[(dichlorophosphorus)- j,-nitrido]) [Allcock, 1976, 1986, 2002 Allcock and Connolly, 1985 Archer, 2001 De Jaeger and Gleria, 1998 Liu and Stannett, 1990 Majumdar et al., 1989, 1990 Manners, 1996 Potts et al., 1989 Scopelianos and Allcock, 1987 Sennett et al., 1986],... 

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