Monomer copolymerization with

Various methylene derivatives of spiroorthocarbonates and spiroorthocstcrs have been reported to give double ring-opening polymerization e.g. Scheme 4.36). Like the parent monocyclic systems, these monomers can be sluggish to polymerize and reactivity ratios are such that they do not undergo ready copolymerization with acrylic and styrenic monomers. Copolymerizations with VAc have been reported.170 These monomers, like other acetals, show marked acid sensitivity. 

As described earlier, the choice of bisphenols for the polymerization of poly(arylene ether ketone)s is large. In particular, the electrochemical properties of the above monomer copolymerized with bisphenol AF were studied. The fundamental PEM characteristics (water uptake and conductivity) were analogous to those of the BPSH systems for a given lEC. 

The low temperature peroxyborane system is very effective for converting thiocarbonyl fluoride to homopolymer. The product is comparable to those formed by anionic polymerization. Since polymerization of thiocarbonyl fluoride is substantially slower than that of the chlorofiuoride, this monomer copolymerizes with exceptional ease with a large number of vinyl compounds to give products that appear to be random copolymers. 

Table 7. Summary of monomers copolymerized with DADMAC ... 

No quantitative data exist for the copolymerization of macrocyclic MCM. Thus attempts to copolymerize hemin with such monomers as vinylpyrrolidone (VPd) and vinylimidazole (Vim) were unsuccessful [92]. The comonomers are classed into two types, viz., -conjugated on nonconjugated. Conjugated monomers copolymerize with macrocyclic MCM as follows ... 

The second type includes a functionalized monomer copolymerized with styrene and DVB. For example, j)-bromostyrene may be included in the reaction mixture to provide the desired concentration of functional groups in the support. These groups may eventually be converted into phosphines by reaction with lithium diphenylphosphide. Such resins with low phosphine concentrations are the supports of choice for attachment of monophosphine-substituted metal clusters because the ligands are sparsely and almost randomly distributed in the polymers (5). 

Hydrophilic copolymers that reduce the viscosity of detergent slurries are disclosed in U.S. Patent 5,733,861. Viscosity-reducing properties are illustrated using data obtained from a Brookfield viscometer, Spindle no. 4,20 r/min, at 25°C. The copolymer comprises an unsaturated hydrophilic monomer copolymerized with an oxyethylated monomer. 

NMR analysis has indicated [9b] that the olefin used does not isomerize during copolymerization. Various vinyl monomers copolymerize with SO2 such as vinyl chloride, styrene, acrylamide, and chloroprene. However, methyl methacrylate is reported [9b] to homopolymerize in SO2 when used as a solvent (cationially or radically) but not to form polysulfones (sulfur dioxide copolymers). 

The efficiency of this process is usually less than one cross-link per peroxide molecule decomposed. To increase the cross-linking efficiency, small amounts of unsaturation are introduced into the polymer structure. We have already discussed EPDM polymers, which are essentially diene monomers copolymerized with ethylene-propylene (EPR) polymers. For polysiloxanes, copolymerization of small amounts of vinyl-methylsilanol greatly enhances cross-linkability (Equation 5.7). The unsaturation introduced into an otherwise saturated structure provides additional sites for cross-linking through chain reaction. 

The search for improvements in polymer characteristics has led to a variety of techniques for modification of polymer properties. One with a clearly chemical basis is the process of copolymerization. This can be carried out by polymerization of a mixture of monomers, both of which are susceptible to the operating polymerization mechanism. The extent of incorporation of each monomer under these conditions is a function of their concentration and relative reactivities toward the reactive site on the polymer chain. Certain pairs of monomers copolymerize with alternating structure ... 

Influences due to steric hindrance are mostly swamped by those due to polarity and resonance stabilization. For example, 1,2-disubstituted ethylene monomers form random copolymers with comonomers of similar polarity, i.e., dimethyl fumarate/vinyl chloride. If the polarities differ greatly, even alternating copolymers can be formed because of the formation of CT complexes, as, for example, with maleic anhydride/styrene (see also Section 22.3). Even two 1,2-disubstituted monomers copolymerize with each other if the polarities differ very greatly, as happens with, for example, maleic anhydride and stilbene, since the polar interaction in the transition state helps to overcome the steric hindrance. Threefold substituted olefins produce an additional stabilization without steric hindrance in the transition state, and so can be easily copolymerized with comomoners of opposite polarity. 

Finally, the unsaturated polyester is free-radically cross-linked by copolymerization with, for example, styrene or methyl methacrylate. Mixtures of the actual unsaturated polyester with these monomers are commercially known as unsaturated polyester resins. The properties of the thermosets can be matched to the application by variations in the acids, glycols, or vinyl monomers. Copolymerization with electronegative comonomers such as styrene or vinyl acetate leads, for example, to alternating copolymers, that is, to short cross-link bridges and therefore, to more rigid thermosets. Alternatively, electropositive comonomers such as methyl methacrylate form long methyl methacrylate bridges between the polyester chains and so produce more flexible polymerizates. 

Figure 3.1 Relationship between monomer composition (vlMA corresponding instantaneous polymer composition for various monomers copolymerized with MMA. (5 = styrene, MA = methyl acrylate,...

In this chapter, we have summarized three different strategies to use phosphonated copolymers as corrosion inhibitors to protect metals. In the first part, the blends of organophosphorus monomers copolymerized with MMA in a PVDF matrix showed relatively good efficiency. These studies also showed phosphonic acid groups as good adhesion/corrosion promoters, but... 

Analysis of fluorescence of urethane acrylic monomer copolymerized with trans-4-(2-methacryloyloxyethylcarbamoyloxymethyl)stilbene (SUM) was performed (Figure 3.19) [73]. 

Scheme 1.18 Monomers copolymerized with r-lactide for synthesizing functional PLA polymers.

TABLE 7.3 Monomers Copolymerized with Fluorinated Monomers and Their Applications... 

Perfluoro-2-inethylene-l,3-dioxolane monomers copolymerizes with various commercially available fluorovinyl monomers, too. Perfluoro-3-methylene-2,4-dioxabicyclo [3,3,0] octane (Figure 16.5F) was copolymerized with chlorotrifluo-roethylene (CTFE), perfluoropropyl vinyl ether, perfluoromethyl vinyl ether, and vinylidene fluoride [23] by a free radical initiator such as perfluorodibenzoylperox-ide or tert-butyl peroxypivalate in bulk or in solution, respectively (see Figure 16.9). 

Hydrocortisone 21-crotonate was prepared by the acylation of hydrocortisone. This monomer copolymerized with N-vinylpyrrolidone in DMF solution at 65°, using AIBN as the free-radical initiator. The product contained 4.7 mol% of the steroid [65]. 

Copolymers of the Teflon AF series are prepared in four steps starting with hexafluoro-acetone (HFA) and ethylene oxide (EO). Condensation reactions of HFA and EO result in 2,2-bis-trifluoromethyl-l,3-dioxolane, which is successively chlorinated, fluorinated, and dechlorinated to give the 2,2-bis-trifluoromethyl-4,5-difluoro-l,3-dioxole (TFMDFD) monomer (Hung, 1993 Resnick, 1976). This monomer copolymerizes with tetrafluoro-ethylene (TFE). The physical properties of these amorphous copolymers vary according to the relative amoimts of the co-monomers, TFMDFD and TFE. Currently, DuPont is producing two commercial grades, AF-1600 and AF-2400. Teflon AF-2400 and AF-1600 are the names of copolymers for which n = 0.87 and 0.65, respectively, where n is the percentage of the TFMDFD monomer (see Fig. 24.9). Table 24.4 summarizes physical properties of the two fluoropolymers. 

The RID profile can be controlled by conduction of simultaneous diffusion of several monomers copolymerized with the matrix, which possess different atomic refractions and molecular masses ... 

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