Styrene-methylmethacrylates

H Jagt, Y Dirix, R Hikmet, and C Bastiaansen, Linear polarizers based on polymer blends oriented blends of poly(ethylene-2,6-naphthalenedicarboxylate) and a poly(styrene/methylmethacrylate) copolymer, Jpn. J. Appl. Phys., 37 4389-4392, 1998. 

Fawcett, A. H. Foster, A. B. Hania, M. Hohn, M. Mazebedi, J. L. McGaffery, G. O. Mullen, E. Toner, D. Silicone Graft Copolymers with Acrylonitrile, Ghloroprene, Styrene, Methylmethacrylate, and an Olefin. In Synthesis and Properties of Silicones and Silicone-Modified Materials-, Clarson, S. J., Fitzgerald, J. J., Owen, M. J., Smith, S. D., Van Dyke, M. E., Eds. ACS Symposium Series 838 American Chemical Society Washington, DC, 2003 pp 318-328. 

The polymerization of olefinic compounds like acrylonitrile, vinyl chloride, styrene, methylmethacrylate can be initiated by anion. The mechanism, in general, can be given as... 

Several reports have appeared in which the UV absorption spectrum of PS was found to be qualitatively similar to an alkyl benzene model compound. Vala and Rice15> demonstrated the similarity between atactic PS and ethyl benzene this was confirmed for atactic PS in cyclohexane by Hirayama 16) and in tetrahydrofuran by Abuin 17>. Bovey and co-workers20) found that absorbance spectra for isotactic PS, atactic PS, and styrene-methylmethacrylate copolymers in 1,2-dichloroethane were roughly similar to that of toluene. 

Copolymerizations initiated by lithium metal should give the same product as produced from lithium alkyls. Usually the radical ends produced by electron transfer initiation have so short a lifetime they can have no influence on the copolymerization. This is true for instance in the copolymerization of isoprene and styrene (50). The product is identical if initiated by lithium metal or by butyllithium. With the styrene-methylmethacrylate system, however, differences are observed (79,80,82). Whereas the butyllithium initiated copolymer contains no styrene at low conversions, the one initiated by lithium metal has a high styrene content if the reaction is carried out in bulk and a moderate one even in tetrahydrofuran. These facts led O Driscoll and Tobolsky (80) to suggest that initiation with lithium occurs by electron exchange and that in this case the radical ends are sufficiently long-lived to produce simultaneous radical and anionic reactions at opposite ends of the chain. Only in certain rather exceptional circumstances would the free radical reaction be of importance. Some of the conditions required have been discussed by Tobolsky and Hartley (111). The anionic reaction should be slow. This is normally true for lithium based catalysts in hydrocarbon solvents. No evidence of appreciable radical participation is observed for initiation by sodium and potassium. The monomers should show a fast radical reaction. If styrene is replaced by isoprene, no isoprene is found in the copolymer for isoprene polymerizes slowly by free radical initiation. Most important of all, initiation should be slow to produce a low steady concentration of radical-anions. An initiator which produces an almost instantaneous and complete electron transfer to monomer produces a high radical concentration which will ensure their rapid mutual termination. 

A Study of the Flow Properties of a Styrene-Methylmethacrylate Diblock Copolymer and SBS Triblock Copolymers... 

Since A and B are constants for a given copolymer and the possible temperature interval is relatively limited, a transition is predicted at an approximately constant shear stress. Melt transitions have in fact been reported at approximately constant shear stresses for styrene-butadiene-styrene triblock copolymers (4). However, this behavior was certainly not observed for the styrene methylmethacrylate diblock copolymer,... 

Since the data for the styrene-methylmethacrylate copolymer show that Tcr and ycr occur (Figure 1) very close to the Newtonian range, this empirical procedure should give reliable values of zero shear viscosity. 

Table I. Data for the Styrene—Methylmethacrylate Diblock Copolymers...

Styrene—methylmethacrylate Diblock Copolymer. Referring to Meier s (3) work, we expect that our model system consists of rather small spherical domains of PMMA blocks in a PS matrix (domain diameter around 500 A). The method of precipitation should point to the same conclusion. 

Figure 7.5 Graphical determination of r and according to Eq. (730) for the system styrene/methylmethacrylate (Mi = styrene M2 = methyl methacrylate). (After Ref. 3.)...

The M[ZnR4] and M[A1R4]2 ate complexes (M = Ca, Sr, Ba) polymerize vinyl and conjugated diene monomers including styrene, methylmethacrylate, acrylonitrile, vinyl-ketones, isoprene and butadiene . The bimetallic complexes produce polymers of differing microstructure to that formed by simple alkaline-earth metal initiators, so that the presence of Zn or A1 influences the stereochemistry of propagation. Thus, polybutadiene obtained in benzene from a Ba-Zn initiator contains more than 90% 1,4-bonds (trans-1,4 75-81 %) ... 

The selected monomers are acrylonitrile (ACN), styrene, a-methyl styrene methylmethacrylate, hydroxyalkyl acrylates and methacrylates, vinyl chloride and others [1-10, 13-18]. The most favoured monomers for industrial production of graft polyether polyols are ACN and styrene [1-10, 18-29]. The resulting products from the radical polymerisation of vinylic monomers in polyethers are opaque, generally white dispersions (except those derived from ACN, which are yellow dispersions). A graft polyether polyol has three polymeric components ... 

Equation (7.52) can also be derived from Eq. (7.43) by eliminating radical concentrations with the help of two steady-state assumptions written as Eqs. (7.44) and (7.47) and then using the definitions of ri and r2. Equation (7.52) represents a one-parameter model for the copoly merization rate (Melville et al., 1947) containing the parameter (p. Statistically, (p is expected to equal unity. However, the values of (p obtained in practice by inserting experimental copolymerization rates into Eq. (7.52) are frequently greater than unity. (For styrene-methylmethacrylate, for... 

PB grafted with styrene, methylmethacrylate, and maleic anhydride (ABSM-MA) or a mixture of ABS and SMM-MA processability, high impact strength, mechanical properties Dufour, 1982... 

Poly(2,6-dimethyl-p-phenylene ether) (PPE) was rarely blended with acrylics, viz. with styrene-methylmethacrylate-co-CW-polyisoprene [Abolins and Reinhardt, 1976] PMMA [Izawa and Nakanishi, 1973 Matsunaga et al., 1974],... 

Graft copolymer acrylonitrile-butadiene-styrene-methylmethacrylate, ABSM PDMS Ethylene-hydroxyethyl methacrylate (EHEMA)... 

We may find confirmation for our statement about the thermodynamic incompatibility of linear polystyrene with the styrene-DVB copolymer in experiments by Wong et al. [269]. These authors reported similarities in the phase separation power of linear polystyrene and that of linear styrene-methylmethacrylate copolymer, the latter being a priori incompatible with the styrene-DVB network. Complete incompatibility of polystyrene with linear polydimethylsiloxane facihtates phase separation and results in the formation of a porous styrene-DVB network on adding as little as 0.5-1% of the above porogen to the initial comonomer mixture (Fig. 3.2, curves 4). It is also not surprising that the porosity of copolymers induced by linear polystyrene and linear polydimethylsiloxane is almost the same when the DVB content exceeds 10%. At a DVB content that hi, the network formed differs fundamentally from linear polystyrene, as from any alien polymer. 

Acrylonitrile-butadiene elastomers Polyacetylene Styrene-acrylonitiile Styrene-butadiene elastomers Styrene-methylmethacrylate cojxjlymer... 

S tyrene- acrylonitrile Styrene-butadiene elastomers Styrene-methylmethacrylate copolymer Sulfo-ethylene-propylene-diene monomer ionomers Syndiotactic polystyrene... 

Ki-aton G1600 SEES Perfluorinated ionomers Phenolic resins Polystyrene, head-to-head Poly(yinyl chloride), head-to-head S tyrene- acrylonitrile Styrene-butadiene elastomers Styrene-methylmethacrylate copolymer Sulfo-ethylene-propylene-diene monomer ionomers Vinylidene fluoride-hexafluoropropylene elastomers Chemigum... 

Methylstyrene-styrene-acrylonitrile-grafted polybutadiene or with maleated styrene-methylmethacrylate-butadiene (ABS-MA) Processability, high impact strength, mechanical properties Dufour 1988... 

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