Polystyrene-styrene-acetone

Styrene is a colorless Hquid with an aromatic odor. Important physical properties of styrene are shown in Table 1 (1). Styrene is infinitely soluble in acetone, carbon tetrachloride, benzene, ether, / -heptane, and ethanol. Nearly all of the commercial styrene is consumed in polymerization and copolymerization processes. Common methods in plastics technology such as mass, suspension, solution, and emulsion polymerization can be used to manufacture polystyrene and styrene copolymers with different physical characteristics, but processes relating to the first two methods account for most of the styrene polymers currendy (ca 1996) being manufactured (2—8). Polymerization generally takes place by free-radical reactions initiated thermally or catalyticaHy. Polymerization occurs slowly even at ambient temperatures. It can be retarded by inhibitors. 

Deionized water (720 g), sodium lauryl sulfate (4.3 g), dioctanoyl peroxide (40 g), and acetone (133 g) were emulsified using an ultrasonic probe for 10 minutes. The step 1 polystyrene seed (48.0 g seed, 578 g latex) was added to the emulsion together with lauryl sulfate (0.8 g) and acetone (29.6 g). The mixture was transferred to a flask and left to agitate at approximately 25°C for 48 hours. Acetone was then removed and the solution added to a 5-liter double-walled glass reactor. The temperature was increased to 40°C while styrene (336 g) and divinyl benzene (0.88 g) were added drop-wise over approximately 60 minutes. After 4 hours the mixture was treated with deionized water (1200 g), potassium iodide (1.28 g), and polyvinyl pyrrolidone (18.48 g) with the temperature increased to 70°C. The polymerization continued for 6 hours at 70°C and 1 hour at 90°C. Styrene-based oligomer particles with a diameter of 1.7 pm and with a narrow size distribution were obtained. 

The only product obtained by the copolymerization of styrene and maleic anhydride in acetone was the alternating copolymer even in the presence of more than equimolar quantities of either styrene or maleic anhydride. However, as shown by the data in Table I, larger quantities were obtained than could be accounted for by the formation of the alternating copolymer when excess styrene was used for the copolymerization in benzene solutions. In addition to the precipitates, there was also a trace of benzene-soluble product, which was shown to be polystyrene by infrared spectrometric (28) and pyrolytic gas chromatographic techniques (26). 

The benzene-derived petrochemicals in Figure 4.15 are intermediate feedstocks for styrenic and phenolic plastics. In the styrenics chain, ethylbenzene is dehydrogenated to styrene, to be used as polystyrene monomer or as a copolymer with acrylonitrile and butadiene. In the phenolics chain, cumene is an intermediate for making phenol. Bisphenol A is the condensation product of two moles of phenol and acetone. Phenol and Bisphenol A are used to manufacture resins and polycarbonates. Phenol and cyclohexane are the starting materials for the manufacture of nylon 6. 

In another interesting development, Yei et al. [124] prepared POSS-polystyrene/clay nanocomposites using an emulsion polymerization technique. The emulsion polymerization for both the virgin polystyrene and the nano composite started with stirring a suspension of clay in deionized water for 4h at room temperature. A solution of surfactant ammonium salt of cetylpyridinium chloride or POSS was added and the mixture was stirred for another 4 h. Potassium hydroxide and sodium dodecyl sulphate were added into the solution and the temperature was then raised to 50 °C. Styrene monomer and potassium persulfate were later on added slowly to the flask. Polymerization was performed at 50 °C for 8 h. After cooling, 2.5% aqueous aluminium sulphate was added to the polymerized emulsion, followed by dilute hydrochloric acid, with stirring. Finally, acetone was added to break down the emulsion completely. The polymer was washed several times with methanol and distilled water and then dried overnight in a vacuum oven at 80 °C. The obtained nanocomposite was reported to be exfoliated at up to a 3 wt % content of pristine clay relative to the amount of polystyrene. 

Figure 3. GPC traces for aliquot of "living" polystyrene (starting PS), PS extracted from acetylene/styrene block material (soluble in 10% THF/acetone), and brominated acetylene/styrene block (insoluble in 10%, THF/acetone).

Small amounts of cumene are used as thinners for paints, lacquers, and enamels, and as solvents in paints and other types of coatings. By far the greatest amount of cumene, however, is used as a raw material in the manufacture of phenol, acetone, and methyl styrene. These compounds, in turn, have a great many chemical and industrial uses. Some of the most important uses are the production of plastics, such as polystyrene, phenol-formaldehyde resins, and polycarbonates. 

The solubility of chemically related compounds decreases with increasing molecular mass since the intermolecular forces of interaction increase. For example, benzene is completely miscible with ethanol, whereas anthracene and ethanol are only partially miscible. The influence of molecular mass on solubility is particularly evident in macromolecules. For example, alcohol, acetone, and acetic acid readily dissolve styrene, but not polystyrene vinyl aeetate dissolves in saturated hydrocarbons and ether, whereas poly(vinyl acetate) does not. Cellulose is insoluble in alcohols, polyfethylene glycol) is insoluble in ethers, poly(vinyl chloride) is insoluble in vinyl chloride, and polyacrylonitrile is insoluble in acetonitrile, even though good solubility would be expected on account of the chemical relation between the polymers and monomers. 

Poly[styrene-codivinylbenzene-co-chloromethylstyrene-co-4-[2,2-bis-(ethoxycarbonyl)ethyl]styrene] 2.3 g (100 mmol) sodium were suspended in 150 mL of dry, boiling toluene. 16 g (100 mmol) diethylmalonate was added dropwise. After all the sodium had reacted, 10 g of the chloromethylated polystyrene (41 mmol of CH2CI) was added and the mixture was refluxed for 6 h. After cooling, the resin was filtered, washed with methanol and acetone, and then treated with acetone in a Soxhlet apparatus. The product was dried at 80 °C in vacuo. The polymer eontains 7.1 mmol oxygen per g polymer (11.32 wt. % O) which corresponds to 1.78 mmol malonic ester groups per g polymer. The Cl content is 0.84 mmol per g polymer (2.99 wt. % Cl). IR (KBr) 1736 cm (v C=0 ester). 

Reaction Procedure (Scheme 2.62) Preparation of PS-PdONPs. To a screw-capped vial with a stir har were added 9.0 mg of polystyrene (85 pmol of styrene unit), Pd(OAc)2 (5.5 mg, 25 pmol), and 1.5 M aqueous K2CO3 solution (3 mL). After stirring at 90 °C for 1 h, the reaction mixture was filtered with hot water. Subsequently, the polystyrene-stahilized Pd nanoparticles were washed with hot water (5x1.0 mL) and acetone (5x1.0 mL). 

Until 2003, Chen s [28], Qu s [29-31], and Hu s [32] groups independently reported nanocomposites with polymeric matrices for the first time the. In Hsueh and Chen s work, exfoUated polyimide/LDH was prepared by in situ polymerization of a mixture of aminobenzoate-modified Mg-Al LDH and polyamic acid (polyimide precursor) in N,N-dimethylactamide [28]. In other work, Chen and Qu successfully synthesized exfoliated polyethylene-g-maleic anhydride (PE-g-MA)/LDH nanocomposites by refluxing in a nonpolar xylene solution of PE-g-MA [29,30]. Then, Li et al. prepared polyfmethyl methacrylate) (PMMA)/MgAl LDH by exfoliation/adsorption with acetone as cosolvent [32]. Since then, polymer/LDH nanocomposites have attracted extensive interest. The wide variety of polymers used for nanocomposite preparation include polyethylene (PE) [29, 30, 33 9], polystyrene (PS) [48, 50-58], poly(propylene carbonate) [59], poly(3-hydroxybutyrate) [60-62], poly(vinyl chloride) [63], syndiotactic polystyrene [64], polyurethane [65], poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] [66], polypropylene (PP) [48, 67-70], nylon 6 [9,71,72], ethylene vinyl acetate copolymer (EVA) [73-77], poly(L-lactide) [78], poly(ethylene terephthalate) [79, 80], poly(caprolactone) [81], poly(p-dioxanone) [82], poly(vinyl alcohol) [83], PMMA [32,47, 48, 57, 84-93], poly(2-hydroxyethyl methacrylate) [94], poly(styrene-co-methyl methacrylate) [95], polyimide [28], and epoxy [96-98]. These nanocomposites often exhibit enhanced mechanical, thermal, optical, and electrical properties and flame retardancy. Among them, the thermal properties and flame retardancy are the most interesting and will be discussed in the following sections. 

Thus according to the proposed theories >, solvents that are precipitants for polystyrene and are also insoluble in the polyolefin will produce Trommsdorff effects. Experimental data obtained from the grafting of styrene in benzene, dioxan, carbon tetrachloride, chloroform, pyridine and acetone (Figures 2 and 3) show that the grafting yields are low in these solvents and the corresponding grafting patterns are different to those in methanol and related alcohols. Thus the copolymerisation behaviour in all solvents studied in this work, except acetone, is in accordance with the proposed theory. Acetone, being a weak... 

Photoreactions of MA with 1,2-polybutadiene, 1,4-polybutadiene, poly(styrene-co-butadiene), poly(styrene-co-isoprene), polystyrene, and poly(styrene-co-methyl methacrylate) have been studied in air. " In homogeneous solutions, MA addition to the polymers proceeds efficiently by a chain mechanism, where the quantum yield of the photoaddition was greater than unity under irradiation at A >310 nm. From the effects of solvent and photosensitizers and spectroscopic data, a radical chain mechanism was proposed to account for addition and crosslinking of the polymers by MA molecules. The photoaddition reaction was applied to the surface of polymer films. The photoreactions were conducted at the interphase between solid polymer and acetone solution of anhydride and also at the interphase between solid polymer and gaseous anhydride. Irradiation with a 300-W high-pressure lamp brought about considerable surface modification, as shown by wettability and dyeability properties. 

Plastic toys 1 g of the sample is dissolved with 10 mL of an appropriate solvent, for instance acetone for acrylonitrile butadiene styrene (ABS), dichloromethane for polystyrene (PS) and tetrahydrofuran for polyvinylchloride (PVC) in an ultrasonic bath. 10 mL of methanol is added to the solution and shaken. The methanol phase is centrifuged, applied to SPE clean-up and concentrated. 

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