Copolymerization of styrene n-butyl

Two free radical-initiated polymerizations are used in turn as examples the homopolymerization of methyl methaK rylate and the copolymerization of styrene n-butyl methacrylate. 

To study the bulk copolymerization of styrene n-butyl methacrylate both conventional and unconventional GPC analyses were used. The normally obtained chromatograms, (from dual U.V. detectors) primarily provided area ratios intficative of composition as a function of retention volume. However, even this information was only obtainable after average compositions had been otherwise determined. Furthermore, in general, since the GPC normally separates on the basis of hydrodynamic volume, the polydispersity of aU polymer molecular properties at e h retention time is of serious concern. 

PolylStyrene co-n-Butyl Methacrylate) Fractionation. OC was developed with the particular idea of elucidating the kinetics of the free radical copolymerization of styrene n-butyl methacrylate. Thus, this polymer provided the main focus of the work. 

Radical copolymerization of styrene and 10% DVB together with various triorganotin-4-vinylbenzoates (using trimethyl-, tri-n-butyl-, and triphenyl-tin) leads to the corresponding polymer-supported tin carboxylates. ... 

Percy and coworkers [39,40] synthesized colloidal dispersions of polymer-silica nanocomposite particles by homopolymerizing 4-vinylpyridine or copolymerizing 4-vinylpyridine with either methyl methacrylate, styrene, n-butyl acrylate or n-butyl methacrylate in the presence of fine-particle silica sols using a free-radical in aqueous media at 60°C. No surfactants were used and a strong acid-based interaction was assumed to be a prerequisite for nanocomposite formation. The nanocomposite particles had comparatively narrow size distributions with mean particle diameters of 150-250 nm and silica contents between 8 and 54 wt.%. The colloidal dispersions were stable at solids contents above 20 wt.%. 

Montei and coworkers [240] reported that Nickel complexes [(X,0)NiR(PPh3)] (X = N or P), designed for the polymerization of ethylene, are effective for home- and copolymerization of butyl acrylate, methyl methacrylate, and styrene. Their role as radical initiators was demonstrated from the calculation of the copolymerization reactivity ratios. It was shown that the efficiency of the radical initiation is improved by the addition of PPhs to the nickel complexes as well as by increasing the temperature. The dual role of nickel complex as radical initiators and catalysts was exploited to succeed in the copolymerization of ethylene with butyl acrylate and methyl methacrylate. 

Copolymerization of 4-vinylphenyl isocyanate and styrene at 60°C in toluene in the presence of AIBN affords the expected copolymers (44). Also, 1 1 copolymers from vinyl isocyanate and maleic anhydride are known (54). The copolymeriation of n-butyl isocyanate with a variety of olefins is conducted in toluene/THF at —80°C, using sodium biphenyl as initiator (55). Anionic copolymerization of styrene and hexyl isocyanate affords rod-coil block copolymers. The st5Tene polsrmer forms the coil block, while the polyisocyanate block assumes the rod shape (56). Vinyl-, 9-decenyl-, or y3-allyloxyethyl isocyanate imdergoes copolymerization reactions with styrene or methyl methacrylate (57). 

Arehart, S. V., and Matyjaszewski, K. (1999). Atom transfer radical copolymerization of styrene and n-butyl acrylate. Macromolecules, 32(7) 2221-2231. 

These equations are consistent with the work of Nomura and Fujita [82]. The validity of Eqs. (4.36)- (4.38) was confirmed experimentally for the emulsion copolymerizations of the styrene-methyl acrylate, styrene-n-butyl acrylate and methyl acrylate-n-butyl acrylate pairs. As a result of this... 

GugUotta et al. [23] developed a new approach to estimate the monomer conversion and copolymer composition in semibatch emulsion copolymerization systems based on reaction calorimetric measurements. The vaUdity of this technique was confirmed by the semibatch emulsion copolymerizations of both the styrene-n-butyl acrylate and vinyl acetate-n-butyl acrylate. 

Recently, free-radical homopolymerizations and copolymerizations of styrene were performed in toluene and iV,N-dimethylformamide (DMF) as solvents in the presence of different initiators (i.e., tert-butyl perbenzoate (tBPB), dibenzoyl peroxide (DBPO), di-terf-peroxide (DtBP), dicumyl peroxide (DCP), and lauryl peroxide (LP) (Figure 7)). ... 

Copolymers of diallyl itaconate [2767-99-9] with AJ-vinylpyrrolidinone and styrene have been proposed as oxygen-permeable contact lenses (qv) (77). Reactivity ratios have been studied ia the copolymerization of diallyl tartrate (78). A lens of a high refractive iadex n- = 1.63) and a heat distortion above 280°C has been reported for diallyl 2,6-naphthalene dicarboxylate [51223-57-5] (79). Diallyl chlorendate [3232-62-0] polymerized ia the presence of di-/-butyl peroxide gives a lens with a refractive iadex of n = 1.57 (80). Hardness as high as Rockwell 150 is obtained by polymerization of triaHyl trimeUitate [2694-54-4] initiated by benzoyl peroxide (81). 

Figure 2.3 Relationship between polydispersity of the resulting random copolymers and mole percent of styrene in the feed mixture for the copolymerization of (i) styrene and n-butyl acrylate (Ob and (ii) styrene and methyl methacrylate ( ) mediated by 14...

Table 8 Block copolymerization of poly(styrene)- -(rerr-butyl acrylate) at different macroinitia-tor to monomer ratios. PSn(n) = degree of polymerization of the PS macroinitiator ...

Monomer reactivity ratios and copolymer compositions in many anionic copolymerizations are altered by changes in the solvent or counterion. Table 6-12 shows data for styrene-isoprene copolymerization at 25°C by n-butyl lithium [Kelley and Tobolsky, 1959]. As in the case of cationic copolymerization, the effects of solvent and counterion cannot be considered independently of each other. For the tightly bound lithium counterion, there are large effects due to the solvent. In poor solvents the copolymer is rich in the less reactive (based on relative rates of homopolymerization) isoprene because isoprene is preferentially complexed by lithium ion. (The complexing of 1,3-dienes with lithium ion is discussed further in Sec. 8-6b). In good solvents preferential solvation by monomer is much less important and the inherent greater reactivity of styrene exerts itself. The quantitative effect of solvent on copolymer composition is less for the more loosely bound sodium counterion. 

Korotkov and Rakova (53) found that butadiene was more active in copolymerization with isoprene with lithium catalyst, although in homopolymerization isoprene is three times faster. Korotkov and Chesnokova (33) studied the copolymerization of butadiene and styrene with n-butyl lithium in benzene. Butadiene polymerized before much of the styrene was consumed. They claimed the formation of block polymers consisting initially of polybutadiene and the polystyrene chain attached. 

Kuntz (33) reported on the copolymerization of butadiene and styrene in n-heptane at 30° using n-butyl lithium. Although styrene homopolymerized six times faster than butadiene, the copolymerization rate was initially the same as that of butadiene homopolymerization and then increased markedly. It was found that about 80% of the styrene remained when 90% of the butadiene was consumed and that the increase in rate coincided with the almost complete consumption of butadiene. With added tetrahydrofuran, the rate of polymerization was faster and about 30% styrene was found in the initial copolymer. 

Polymers and copolymers were laboratory-prepared samples. Samples W4 and W7 of the diblock copolymer AB poly(styrene-fo-tetramethylene oxide) (PS—PT) were synthesized by producing a polystyrene prepolymer whose terminal group was transformed to a macroinitiator for the polymerization of THF. Samples B13 and B16 of the diblock copolymer AB poly[styrene-h-(dimethyl siloxane)] (PS-PDMS) were prepared by sequential anionic polymerization. Samples of statistical copolymers of styrene and n-butyl methacrylate (PSBMA) were produced by radical copolymerization. Details of synthetic and characterization methods have been reported elsewhere (15, 17-19). 

Typically, carboxylate ionomers are prepared by direct copolymerization of acrylic or methacrylic acid with ethylene, styrene or similar comonomers by free radical copolymerization (65). More recently, a number of copolymerizations involving sulfonated monomers have been described. For example, Weiss et al. (66-69) prepared ionomers by a free-radical, emulsion copolymerization of sodium sulfonated styrene with butadiene or styrene. Similarly, Allen et al. (70) copolymerized n-butyl acrylate with salts of sulfonated styrene. The ionomers prepared by this route, however, were reported to be "blocky" with regard to the incorporation of the sulfonated styrene monomer. Salamone et al. (71-76) prepared ionomers based on the copolymerization of a neutral monomer, such as styrene, methyl methacrylate, or n-butyl acrylate, with a cationic-anionic monomer pair, 3-methacrylamidopropyl-trimethylammonium 2-acrylamlde-2-methylpropane sulfonate. 

Consider the copolymerization of 1,3-butadiene with the following monomers n-butyl vinyl ether, methyl methacrylate, methyl acrylate, styrene, vinyl acetate, acrylonitrile, maleic anhydride. If the copolymerizations were carried out using cationic initiation, what would be expected qualitatively for the copolymer compositions List the copolymers in order of their increasing butadiene content. Would copolymers be formed from each of the comonomer pairs Explain what would be observed if one used anionic initiation ... 

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