Copolymer solutions dichloroethane

Weiss et al. [75] have synthesized Na and Zn salt of sulfonated styrene(ethylene-co-butylene)-styrene triblock ionomer. The starting material is a hydrogenated triblock copolymer of styrene and butadiene with a rubber mid-block and PS end-blocks. After hydrogenation, the mid-block is converted to a random copolymer of ethylene and butylene. Ethyl sulfonate is used to sulfonate the block copolymer in 1,2-dichloroethane solution at 50°C using the procedure developed by Makowski et al. [76]. The sulfonic acid form of the functionalized polymer is recovered by steam stripping. The neutralization reaction is carried out in toluene-methanol solution using the appropriate metal hydroxide or acetate. 

To obtain a good separation of polymer, the precipitation ranges of BD-AN copolymer and PVC homopolymer must be very different. We chose dichloroethane-methanol system (Figure 2). Visible dissolution requires warming at 70 °C for 10 minutes, but some copolymers are totally soluble at 20 °C giving cloudy solutions. 

Inoue et al.1115,1161 synthesized polyvinyl/polypeptide graft copolymers by attaching branches of p-phenylazobenzyl/P-benzyl-L-aspartate (X) to poly(hydroxyethyl methacrylate) and poly(butyl methacrylate), and then prepared the corresponding membranes by casting dichloroethane solutions of the polymers. The membranes were stable in trimethylphosphate. 

Block copolymers with a hydrophobic polyvinyl block and a hydrophobic polypeptide block (BG, SG, SC, SL, BCK and SCK copolymers) exhibit well organized meso-phases in dioxane, 1,2-dichloroethane, 2,3-dichloro 1-propene, etc., solutions. These mesophases are observed for solvent concentrations smaller than about 60% and for dry samples obtained by evaporation of the solvent at a slow rate. 

The photoresponsive helicity inversion process of 4 was applied to the photoregulation of permeability across a membrane from a graft copolymer containing the photoresponsive peptide (7) as a branch (Fig. 2) [44]. The graft polymer membrane casted from a 1,2-dichloroethane solution, followed by immersion in trimethylphosphate, exhibited a positive CD band at 215 nm, characteristic to... 

It has been reported that in ethyl acetate and dichloroethane solution, the position of the excimer band is concentration dependent The interpretation of solvent effects is complex. Since the compactness of the pdymer coil will affect the efficiency of energy migration and the ccmcentration of aromatic species in conformations suitable for excimer formation, sdvent effects are to be expected in polymers in which excimer formation is the result of nearest-neighbour interactions, as is the case in styrene as shown in studies on styrene-methyl methacrylate copolymers ... 

Figure 12.1.5. Viscosity ofPMMA solutions indifferent Figure 12.1.6. Relative viscosity of block copolymers solvents vs. PMMA concentration. Basic solvents with and and without segments capable of forming tetrahydrofuran, THF, and dioxane, DXN neutral tolu- complexes vs. concentration. [Data from I C De Witte, ene, TOL and CCI4 acidic 1,2-dichloroethane, DCE, b G Bogdanov, E J Goethals, Macromol. Symp., 118, CHCI3, and dichloromethane, DCM. [Adapted, by per- 237-46 (1997).] mission, from M L Abel, M M Chehimi, Synthetic Metals, 66, No.3, 225-33 (1994).]...

The monomers were synthesized according to the procedure described earlier in7-9. All polymers were obtained by radical polymerization in solution (initiator - azo-bis-isobutyronitrile, solvent - benzene), and subsequently purified by triple reprecipitation from benzene solutions with hot methanol. The copolymer composition was determined by UV-spectroscopy of their dichloroethane solutions. 

Terpolymers on the basis of 4, 4 bisphenoxybisphenylsulfone, 4,4 bi-sphenoxybenzophenone and terephthaloylchloride were produced in Ref. [383] by low-temperature polycondensation. The reaction was lead in solution of 1, 2-dichloroethane in the presence of AlClj and N-methyl-2-p5UTolidone. It has been found that with increasing content of links of 4, 4 bisphenoxybisphenylsulfone in copolymer their glassing and dissipation temperatures increase, but melting point and temperature of crystallization decrease. 

A Pt wire (diameter, 0.5 mm) sealed into the end of a glass tube (diameter, 5 mm) to leave 1 cm of the wire exposed was dipped into 1,2-dichloroethane solution of the block copolymer (1 wt-%) and dried to give the polymer-coated electrode. The electrode was then treated for 12 h with a ternary solvent of water, methanol, and 2-propanol (1 2 2, by volume) containing 0.5 wt-% KOH in order to hydrolyze the mefoyl ester group of the polypeptide, being converted to the carboxylate group. 

The PCL used in these studies (PCL-767 Mw = 40 400 g mol, Mw/Mn = 2.61) was obtained from the Union Carbide Corporation. Copolymers of styrene and acrylonitrile (SAN) were synthesized at 60 °C using ethylbenzene as a solvent and azoisobutyronitrile (AIBN), at a concentration of 0.02 mol 1 as the initiator. The conversion was less than 5%. The acrylonitrile content in SAN was in range 10-35wt%. SAN containing 27.5 wt% acrylonitrile (briefly, SAN-27.5) exhibited an interesting phase behavior and was studied extensively, the molecular weight data acquired were M = 169 000 g mol Mw/M = 2.09. The blends were prepared by casting a 5wt% solution of both polymers in 1,2-dichloroethane onto a cover... 

A divinylbenzene-ethylene-styrene copolymer is sulfonated by 3.5-10% solutions of chlorosulfonic acid in organic solvents, e.g. chloroform or 1,2-dichloroethane at RT to yield cation-exchange resins. Porous st)rrene-divinyl-benzene-ethylvinylbenzene copolymers have also been treated with the reagent and hydrazine hydrate to form ion-exchange resins containing sulfonyl hydrazide groups. ... 

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