Styrene/MMA

A wide range of polymer networks are constructed in this manner. Poly(vinyltrichloacetate) was used as the coinitiator with styrene, MMA and chloroprene as cross-linking units. Polycarbonates, polystyrene, N-haloge-nated polyamide, polypeptides, and cellulose acetate, suitably functionalized, have been used as a coinitiator... 

Bamford and Mullik [62] have succeeded in photografting a vinyl monomer onto a styrene-MMA copolymer using the Mn2(CO)io/C2F4 photoinitiating system in acetic acid. The following scheme was reported for this process ... 

The photo-induced process of modification of cellulose and its derivatives was reported by Geacintov and coworkers [67,68]. Thus, acrylonitrile, vinyl acetate, styrene, MMA, and the binary system of styrene and AN were grafted onto cellulose and cellulose derivatives. In... 

Nomura and Fujita (12.), Figures 8 and 9, styrene/MMA copolymerization in a batch reactor at 50 °C using seed particles. 

Data of Nomura and Funita (12). The predictive capabilities of EPM for copolymerizations are shown in Figures 8-9. Nomura has published a very extensive set of seeded experimental data for the system styrene-MMA. Figures 8 and 9 summarize the EPM calculations for two of these runs which were carried out in a batch reactor at 50 °C at an initiator concentration of 1.25 g dm 3 water. The concentration of the seeded particles was 6x10 dm 3 and the total mass of monomer was 200 g dm 3. The ratio of the mass of MMA to the total monomer was 0.5 and 0.1 in Figures 8 and 9 respectively. The agreement between the measured and predicted values of the total monomer conversion, the copolymer composition, and the concentration of the two monomers in the latex particles is excellent. The transition from Interval II to Interval III is predicted satisfactorily. In accordance with the experimental observations, EPM predicted no new particle formation under the conditions of this run. 

The verification of EPM on the well characterized styrene and styrene-MMA polymerizations has allowed us to use the same model structure to obtain fundamental insights into emulsion polymerizations involving other monomers of significant importance to Du Pont. 

St styrene, MMA methyl methacrylate, IB isobutene, VAc vinyl acetate, VC1 vinyl chloride, DiPF diisopropyl fumarate, AA acrylic acid, MAn maleic anhydride, IBVE isobutyl vinyl ether. 

Other NAD microspheres are composed of styrene, MMA, hydroxyethyl acrylate, acrylic acid and acrylonitrile and are blended with acrylic copolymers and melamine/formaldehyde resins [341,342]. Particles of this polymer are used as rheology modifiers to prevent sagging in automotive coatings and for controlling the orientation of metal flake pigments. 

The additional complexity present in block copolymer synthesis is the order of monomer polymerization and/or the requirement in some cases to modify the reactivity of the propagating center during the transition from one block to the next block. This is due to the requirement that the nucleophilicity of the initiating block be equal or greater than the resulting propagating chain end of the second block. Therefore the synthesis of block copolymers by sequential polymerization generally follows the order dienes/styrenics before vinylpyridines before meth(acrylates) before oxiranes/siloxanes. As a consequence, styrene-MMA block copolymers should be prepared by initial polymerization of styrene followed by MMA, while PEO-MMA block copolymers should be prepared by... 

The reactions were carried out in dilute homogeneous solution in dipolar aprotic solvents ([ester]g=0.2-0.4 mole.l- ) using stereoregular (pure I or S) or predominantly syndiotactic radical (R) PMMA, polymethylacrylate (PMA) and radical azeotropic styrene-MMA copolymer (PSMMA, MMA mole.fraction = 0.47) as well as model monomeric (methylpivalate) and dimeric (dimethylglutarate) compounds. The overall reaction is outlined in the simplified scheme ... 

Using a SAM of an asymmetric azo compounds Baum and Brittain [327] homo-and block copolymerized styrene, MMA and N,N -dimethylacrylamide under RAFT conditions in the presence of 2-phenylprop-2-yl dithiobenzoate as the chain... 

In this review, synthesis of block copolymer brushes will be Hmited to the grafting-from method. Hussemann and coworkers [35] were one of the first groups to report copolymer brushes. They prepared the brushes on siUcate substrates using surface-initiated TEMPO-mediated radical polymerization. However, the copolymer brushes were not diblock copolymer brushes in a strict definition. The first block was PS, while the second block was a 1 1 random copolymer of styrene/MMA. Another early report was that of Maty-jaszewski and coworkers [36] who reported the synthesis of poly(styrene-h-ferf-butyl acrylate) brushes by atom transfer radical polymerization (ATRP). 

Difunctional initiators such as sodium naphthalene are useful for producing ABA, BABAB, CAB AC, and other symmetric block copolymers more efficiently by using fewer cycles of monomer additions. Difunctional initiators can also be prepared by reacting a diene such as /n-diisoprope ny I benzene or l,3-bis(l-phenylethenyl)benzene with 2 equiv of butyl-lithium. Monomer B is polymerized by a difunctional initiator followed by monomer A. A polymerizes at both ends of the B block to form an ABA triblock. BABAB or CABAC block copolymers are syntehsized by the addition of monomer B or C to the ABA living polymer. The use of a difunctional initiator is the only way to synthesize a MMA-styrene-MMA triblock polymer since MMA carbanion does not initiate styrene polymerization (except by using a coupling reaction—Sec. 5-4c). 

Rubber-toughened polystyrene composites were obtained similarly by polymerising the dispersed phase of a styrene/SBS solution o/w HIPE [171], or a styrene/MMA/(SBS or butyl methacrylate) o/w HIPE [172], The latter materials were found to be tougher, however, all polymer composites had mechanical properties comparable to bulk materials. Other rubber composite materials have been prepared from PVC and poly(butyl methacrylate) (PBMA) [173], via three routes a) blending partially polymerised o/w HIPEs of vi-nylidene chloride (VDC) and BMA, followed by complete polymerisation b) employing a solution of PBMA in VDC as the dispersed phase, with subsequent polymerisation and c) blending partially polymerised VDC HIPE with BMA monomer, then polymerisation. All materials obtained possessed mixtures of both homopolymers plus some copolymer, and had better mechanical properties than the linear copolymers. The third method was found to produce the best material. 

Photo-grafting of styrene, MMA and PPA were achieved by performing the photolysis of hydroperoxidized polymers in the presence of the monomer at low pressure (typically 5 mm Hg). Photo-grafting of PPA, TP A, TPM, St-NO and TEMPO were performed in methanol solution of each monomers too. IR and NMR measurements ensured that the grafting was successful according the monomers, 1 to 6 units per one OOH group were grafteded. 

EO)12-A as examples at the extremes of the HLB range available. In all cases both groups of surfactants emulsified the monomers styrene, MMA, and vinyl acetate (VAc). There was no difference between the conventional surfactants and their polymerization analogues with styrene. In the case of the MMA and VAc systems, the polymerizable surfactants yield much less stable emulsions than their non-polymerizable analogues. 

Many different vinyl monomers (9) have been used to make wood-polymers during the past ten years, but methyl methacrylate (MMA) appears to be the preferred monomer for both the catalyst-heat and radiation processes. In fact, MMA is the only monomer that can be economically polymerized with gamma radiation. On the other hand, all types of liquid vinyl monomers can be polymerized with Vazo or peroxide catalysts. In many countries styrene and styrene-MMA mixtures are used with the Vazo or peroxide catalysts. 

The technique has been recently extended to polar media, especially alcohols and their mixtures with water as a continuous phase. Kobayashi et al. [104-107] have reported that poly(2-oxazoline) macromonomers such as 34 and 35 are very effective for the dispersion copolymerization with styrene, MMA, and N-vinyl-formamide in methanol, ethanol, and mixtures of these alcohols with water. They reported that the particle size decreased with increasing initial macromonomer concentration and that poly(2-oxazoline) macromonomers graft-copoly-merized are concentrated on the particle surface to act as steric stabilizers. 

Kennedy 67,77 118) studied the ability of w-styryl-polyisobutene macromonomers to undergo free-radical copolymerization with either styrene or butyl or methyl methacrylate. Here, the macromonomers exhibited a relatively high molecular weight of 9000, and the reaction was stopped after roughly 20% of the comonomer had been converted. The radical reactivity ratios of styrene and methyl methacrylate with respect to macromonomer were found to be equal to 2 and to 0.5, respectively. From these results, Kennedy concluded that in the ra-styrylpolyisobutene/styrene system the reactivity of the macromonomer double bond is reduced whereas with methacrylate as the comonomer the polar effect is the main driving force, yielding reactivities similar to those observed in the classical system styrene/MMA. 

Most pertinent examples are mentioned in the review by Clouet et al. [12] and various monomers were utilized as macroprecursors styrene, MMA, alkyl acrylates, and isoprene. The synthesis of triblock copolymers can be easily achieved by condensation of these macroprecursors with monofunctional polymeric derivatives as shown in the following characteristic example [226] ... 

Although in this example the authors claimed no living character to the synthesis, Opresnik et al. [227,228] described a similar synthesis in which some living character is seen. They also used disulfides as reversible termination agents in the presence of styrene, MMA and ethyl acrylate (EA). The first step involves the synthesis of polymeric precursor 48 under UV cleavage ... 

They are prepared from the addition of CS2 to the corresponding alcohols in basic medium. They are known to exhibit high transfer constants (Cr = 1-20) [21]. Constanza et al. [210], Otsu and Yoshida [49], Uraneck [121] and Fokina et al. [229] intensively studied the polymerization of styrene, MMA and butadiene with these compounds in order to obtain telechelics with functional xanthogens. Furthermore, chemical change (e.g., hydrolysis) was also performed to achieve the synthesis of corresponding a,co-dithiols [229] such as from 49 ... 

Some other interesting copolymers having properties of PVC thermal stabUizers, like poly[Af-(a-benzothiazolonylmethyl)methacrylate-co-methyl methacrylate] [45], of flame retardants like a terpolymer of styrene, acrylonitrile and a polymerizable perbrominated phenol [76] or poly[4-methacryloyloxy-2,3,5,6-tetrabromobenzyldi-phenyl phosphonate-co-methyl methacrylate] [104] (93), bioddes, mostly copolymers of monomers containing tris(n-butyl tin) or triphenyl tin moieties and alkyl acrylates, methacrylates, vinyl acetate, acrylonitrile, styrene or A-vinylpyrrolidone [105], e.g. a terpolymer of styrene, MMA and tri(n-butyl tin) itaconate [106] (94),... 

A different approach to obtain styrene/MMA block copolymers involves the use of bifimctional initiators containing thermal-labile azo and photo-labile benzoin moieties [139]. As a first step, prepolymers are prepared by thermal decomposition of the azo moiety in the presence of one monomer. These photoactive... 

Plots of the relationship between the styrene content and retention volume for copolymers of styrene-acrylate and styrene-methacrylate with the same ester group lay roughly on the same line. This result indicates that a pair of copolymers with the same ester group and the same styrene content could not be separated (24), For example, copolymers of styrene-methyl acrylate and styrene-MMA with the same styrene content cannot be separated by this technique. In copolymers with the same styrene content, styrene-butyl acrylate and styrene-butyl methacrylate copolymers eluted first from a column, the copolymers of ethyl esters were next, and those of methyl esters eluted last. 

The different Mj/M monomers blends used were Styrene/MMA, Sty/VaC and Sty/A-vinylpyrolidone. 

Fig. 1 Molar mass distribution with overlaid chemical composition distribution of a styrene-MMA block copolymer with poor block formation.

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