Copolymerization with /-butyl

AH-acryHc (100%) latex emulsions are commonly recognized as the most durable paints for exterior use. Exterior grades are usuaHy copolymers of methyl methacrylate with butyl acrylate or 2-ethyIhexyl acrylate (see Acrylic ester polymers). Interior grades are based on methyl methacrylate copolymerized with butyl acrylate or ethyl acrylate. AcryHc latex emulsions are not commonly used in interior flat paints because these paints typicaHy do not require the kind of performance characteristics that acryHcs offer. However, for interior semigloss or gloss paints, aH-acryHc polymers and acryHc copolymers are used almost exclusively due to their exceUent gloss potential, adhesion characteristics, as weU as block and print resistance. 

Vinyl acetate is another monomer used in latex manufacture for architectural coatings. When copolymerized with butyl acrylate, it provides a good balance of cost and performance. The interior flat latex paint market in North America is almost completely dominated by vinyl acetate—acryHc copolymers. Vinyl acetate copolymers are typicaHy more hydrophilic than aH-acryHc polymers and do not have the same ultraviolet light resistance as acryHcs as a result. 

The effect of hydrophobicity of the polymer on the permeability of poly(2-hydroxyethyl methacrylate (HEMA)-co-methacrylic acid (MAAc) hydrogels was studied [12], The hydrophobicity was controlled by copolymerization with butyl methacrylate (BMA). The dependence of permeability on pH increased as the hydrophobicity increased even though the rate of diffusion decreased. Cross-link density of the hydrogel also contributed to pH-dependent permeability. 

A similar approach was used in Ref. 103) to obtain the fat-soluble derivatives of heparin by its copolymerization with butyl methacrylate or vinyllaurate and to get high-molecular products with a molecular mass of over 200000 by homopolymerization of the unsaturated heparin derivative. The products were used as thromboresistant... 

Whether all chains bear a terminal vinylic double bond has not been clearly established, and it would be somewhat astonishing if vinylic double bonds did not undergo side reactions since their reactivity in cationic polymerization is quite high. However, the occurrence of terminal p-vinyl benzyl groups is confirmed by the fact that the formed macromonomer readily copolymerizes with butyl acrylate. 

By means of the spatially intermittent reactor, Ito and O Driscoll determined, for example, the absolute rate constant of termination, fct, for methyl methacrylate copolymerization with butyl or dodecyl methacrylate. The value of /ct is a function of the monomer mixture composition [89]. 

The MMA copolymerization with butyl and isobutyl methacrylates or 2,3-epoxypropyl-acrylate has been described U3). In Table 1.4, MMA shows a higher reactivity than its comonomers and the results disagree with literature data. The medium (nature and concentration of the alcohol) influences the monomers reactivity through the solubility, depending on the copolymer nature. The curves, giving the copolymer composition as a function of yield, are only workable when the medium is homogeneous (e.g., with a copolymer of a high MMA content). 

Branched acrylic polymers based upon the copolymerization of acrylates and related monomers with methacrylate macromonomers are particularly useful in waterborne coatings. A macromonomer based upon isobutyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxyethyl methacrylate was copolymerized with butyl acrylate, 2-hydroxyethyl acrylate, meth-acrylic acid, methyl methacrylate, and styrene.518 After neutralization with dimethylethanolamine or inorganic bases, the polymer could be cross-linked with melamine resin on a metal surface. These systems may be used for either pigmented layers or clear coats. 

In order to more systematically understand the effects of VEC copolymerization with butyl acrylate, a series of copolymers was prepared. Table II lists the compositions and characteristics of these copolymers. Complete incorporation of VEC into the copolymers was not achieved under these conditions (Figure 1). The unreacted monomers consisted predominately of VEC only a trace of unreacted butyl acrylate was detected. The amoimt of VEC actually incorporated into the copolymer can be determined by subtraction either using the unreacted monomer data or the conversion data. If the amount of VEC incorporated into the copolymer is compared to what was charged to the reaction, level of incorporation is relatively constant at 60-65%. This is illustrated in Figure 2. 

Mizutani and Hirashima obtained by conventional radical polymerization a photosensitive resin using methacrylic acid, butyl acrylate, and a new phosphorus-containing allyl monomer (Scheme 3.20). To create the new monomer, they treated 9,10-dihydro-9-oxa-10-phosphaphenanthrene (DOPO) with allyl methacrylate at high temperature. By copolymerization with butyl acrylate, they obtained a photosensitive resin that showed good fire resistance. 

Further improvements of the FeX2(PRs)2 catalyst were achieved by screening of the phosphine coligand as well as the halogen ligand. The introduction of more basic ligands, such as PMe(Ph)2 and n-Bu3P, in place of PPhj (Fe-3) improved both the activity and controllability of the MMA polymerization. In particular, Fe-3 in conjunction with a bromide initiator allowed a faster and more controlled polymerization of MMA (M /Mn 1.2) and block copolymerization with butyl methacrylate (BMA). 

VEs do not readily enter into copolymerization by simple cationic polymerization techniques instead, they can be mixed randomly or in blocks with the aid of living polymerization methods. This is on account of the differences in reactivity, resulting in significant rate differentials. Consequendy, reactivity ratios must be taken into account if random copolymers, instead of mixtures of homopolymers, are to be obtained by standard cationic polymeriza tion (50,51). Table 5 illustrates this situation for butyl vinyl ether (BVE) copolymerized with other VEs. The rate constants of polymerization (kp) can differ by one or two orders of magnitude, resulting in homopolymerization of each monomer or incorporation of the faster monomer, followed by the slower (assuming no chain transfer). 

Butyl rubber and other isobutylene polymers of technological importance iaclude various homopolymers and isobutylene copolymers containing unsaturation achieved by copolymerization with isoprene. Bromination or chlorination of the unsaturated site is practiced commercially, and other modifications are beiag iavestigated. 

Kondo maintained his interest in this area, and with his collaborators [62] he recently made detailed investigations on the polymerization and preparation of methyl-4-vinylphenyl-sulfonium bis-(methoxycarbonyl) meth-ylide (Scheme 27) as a new kind of stable vinyl monomer containing the sulfonium ylide structure. It was prepared by heating a solution of 4-methylthiostyrene, dimethyl-diazomalonate, and /-butyl catechol in chlorobenzene at 90°C for 10 h in the presence of anhydride cupric sulfate, and Scheme 27 was polymerized by using a, a -azobisi-sobutyronitrile (AIBN) as the initiator and dimethylsulf-oxide as the solvent at 60°C. The structure of the polymer was confirmed by IR and NMR spectra and elemental analysis. In addition, this monomeric ylide was copolymerized with vinyl monomers such as methyl methacrylate (MMA) and styrene. 

In a related study this group also demonstrated the use of non-volatile solvents in CEC-MS without compromising the quality of spectra that has also been demonstrated using polymer-based monolithic column prepared by in situ copolymerization of butyl methacrylate with sulfonic acid functionalities. 

Uses Copolymerized with methyl acrylate, methyl methacrylate, vinyl acetate, vinyl chloride, or 1,1-dichloroethylene to produce acrylic and modacrylic fibers and high-strength fibers ABS (acrylonitrile-butadiene-styrene) and acrylonitrile-styrene copolymers nitrile rubber cyano-ethylation of cotton synthetic soil block (acrylonitrile polymerized in wood pulp) manufacture of adhesives organic synthesis grain fumigant pesticide monomer for a semi-conductive polymer that can be used similar to inorganic oxide catalysts in dehydrogenation of tert-butyl alcohol to isobutylene and water pharmaceuticals antioxidants dyes and surfactants. 

Coordination copolymerization of ethylene with small amounts of an a-olefin such as 1-butene, 1-hexene, or 1-octene results in the equivalent of the branched, low-density polyethylene produced by radical polymerization. The polyethylene, referred to as linear low-density polyethylene (LLDPE), has controlled amounts of ethyl, n-butyl, and n-hexyl branches, respectively. Copolymerization with propene, 4-methyl-1-pentene, and cycloalk-enes is also practiced. There was little effort to commercialize linear low-density polyethylene (LLDPE) until 1978, when gas-phase technology made the economics of the process very competitive with the high-pressure radical polymerization process [James, 1986]. The expansion of this technology was rapid. The utility of the LLDPE process Emits the need to build new high-pressure plants. New capacity for LDPE has usually involved new plants for the low-pressure gas-phase process, which allows the production of HDPE and LLDPE as well as polypropene. The production of LLDPE in the United States in 2001 was about 8 billion pounds, the same as the production of LDPE. Overall, HDPE and LLDPE, produced by coordination polymerization, comprise two-thirds of all polyethylenes. 

A polystyrene with a functionality such as a methacrylate group copolymerized with a mixture of ethyl and butyl acrylate should yield a graft structure meeting the criteria of a thermoplastic elastomer as shown in Figure 13. The data in this figure show that as the MACROMER content is increased, the tensile... 

In the polymerization of MMA by BuLi the initiator was reported to react first with many more carbonyl groups than with vinyl double bonds at low temperatures O). Therefore, the butyl carbonyl group must be incorporated through the copolymerization of MMA with butyl isopropenyl ketone formed by the former reaction. 

Butyl rubber is produced by a process in which isobutylene is copolymerized with a small amount of isoprene using aluminum chloride catalyst at temperatures around — 150° F. (20). The isoprene is used to provide some unsaturation, yielding a product that can be vulcanized (43). Vulcanized Butyl rubber is characterized by high tensile strength and excellent flex resistance furthermore, as a result of its low residual unsaturation (only 1 to 2% of that of natural rubber) it has outstanding resistance to oxidative aging and low air permeability. These properties combine to make it an ideal material for automobile inner tubes (3), and Butyl rubber has continued to be preferred over natural rubber for this application, even when the latter has been available in adequate supply. 

Butyl rubber is one product formed when isobutylene is copolymerized with a few percents of isoprene. In the Exxon process an isobutylene-methyl chloride mixture containing a small amount of isoprene is mixed at — 100°C with a solution of AICI3 in methyl chloride. An almost instantaneous reaction yields the product, which is insoluble in methyl chloride and forms a fine slurry. Molecular weight can be controlled by adding diisobutylene as a chain-transfer agent. Increased catalyst concentration and temperature also result in lowering molecular weight. The product can be vulcanized and is superior to natural rubber. A solution process carried out in C5-C7 hydrocarbons was developed in the former Soviet Union.471,472... 

The copolymerization of isocyanides, such as cyclohexyl, phenyl, p-toluyl and (r-toluyl—singly with diazomethane (6), or as mixtures of two isocyanides (7)—has been reported. These products are largely insoluble in common organic solvents but are dispersed in dichloroacetic add. Millich and Wang copolymerized sec-butyl isocyanide with a-phenylethyl isocyanide, and obtained a copolymer sparingly soluble in common solvents (8). Recently, Millich and Chenvanij copolymerized a phenylethyl isocyanide with methyl a-isocyanopropionate, and obtained copolymers which have solubilities suitable to conventional solution characterization methods (8,9). 

The first free radical initiated copolymerization was described by Brubakerl) in a patent. A variety of peroxides and hydroperoxides, as well as, 02, were used as initiators. Olefins that were copolymerized with CO included ethylene, propylene, butadiene, CH2=CHX (X—Cl, OAc, CN) and tetrafluoroethylene. A similar procedure was also used to form terpolymers which incorporated CO, C2H4 and a second olefin such as propylene, isobutylene, butadiene, vinyl acetate, tetrafluoroethylene and diethyl maleate. In a subsequent paper, Brubaker 2), Coffman and Hoehn described in detail their procedure for the free radical initiated copolymerization of CO and C2H4. Di(tert-butyl)peroxide was the typical initiator. Combined gas pressures of up to 103 MPa (= 15,000 psi) and reaction temperatures of 120—165 °C were employed. Copolymers of molecular weight up to 8000 were obtained. The percentage of CO present in the C2H4—CO copolymer was dependent on several factors which included reaction temperature, pressure and composition of reaction mixture. Close to 50 mol % incorporation of CO in the copolymer may be achieved by using a monomer mixture that is >70 mol% CO. Other related procedures for the free radical... 

Comparable results were observed for the copolymerization of maleic anhydride and methyl methacrylate (8 = 10.8 for copolymer), methyl acrylate (8 = 10.7 for copolymer), and butyl methacrylate (8 = 10.7 for copolymer). However, the copolymers of maleic anhydride and stearyl methacrylate (8 = 10.3) and maleic anhydride and isobutyl methacrylate (8 = 10.4) have lower solubility parameter values, and hence, a slow homogeneous copolymerization was observed when these monomers were copolymerized with maleic anhydride in benzene. 

High conversions (close to 100%) can be obtained by the dispersion copolymerization of PEO-MA with butyl acrylate initiated by a water-soluble initiator (VA) [80]. The conversion curves have a shape similar to that for the dispersion copolymerization of PEO-MA with styrene. In runs with AIBN the final conversion was around 90% and/or the polymerization was very slow at high conversion. 

The monomer-selective living copolymerization of /-butyl acrylate (/-BuA) and ethyl methacrylate (EMA) was studied on a 750 MHz spectrometer with an H inverse-geometry LC-NMR probe with pulsed-field gradient coils [10]. The detection volume of the flow cell was ca. 60 pi The measurements were performed in chloroform-di, with a flow rate of 0.2ml/min, at 296 K. The copolymers were obtained using bis (2,6-di-/-butylphenoxy) methylaluminium... 

Four polymerization examples are presented here to illustrate both available sensitivity, experimental difficulties, and hopefully some interesting aspects of the polymerization processes. The first two examples are the semi-continuous emulsion polymerization of methyl methacrylate (MMA) and styrene, respectively. The third example is a batch charged copolymerization of butyl acrylate (BA) with MMA. The fourth example is a semi-continuous solution polymerization of an acrylic system. In this last example aliquots were taken manually and analyzed at 29.7°C under static conditions. No further polymerization occurred after the samples were cooled to this temperature. 

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