Polystyrene hydroperoxide

Polystyrene hydroperoxide and poly( -methylstyrene) hydroperoxide were... 

Table 1. Effect of Polystyrene Hydroperoxide and Di-Cup on Stress-Strain Properties of PMS-BD-PMS at 25°C. 

These data indicate that indeed part of the effect of added polystyrene hydroperoxide (Table 1) may be to alter the morphology of the system (e.g., compare sample E with sample C), since both the tensile strength and elongation at break are increased by simply adding an equivalent amount of polystyrene. However, the tensile strength of sample A is twice that of sample E. Therefore, there is another factor, presumably crosslinking of the hard phase, which enhances the tensile strength of sample A versus sample E. 

The acetone supply is strongly influenced by the production of phenol, and so the small difference between total demand and the acetone suppHed by the cumene oxidation process is made up from other sources. The largest use for acetone is in solvents although increasing amounts ate used to make bisphenol A [80-05-7] and methyl methacrylate [80-62-6]. a-Methylstyrene [98-83-9] is produced in controlled quantities from the cleavage of cumene hydroperoxide, or it can be made directly by the dehydrogenation of cumene. About 2% of the cumene produced in 1987 went to a-methylstyrene manufacture for use in poly (a-methylstyrene) and as an ingredient that imparts heat-resistant quaUties to polystyrene plastics. 

Instrumental methods of peroxide analysis feature polarography, which is used to detn hydroperoxides, peroxyesters and diacyl peroxides as well as dicyclohexyl peroxydicarbonate in polystyrene. Other techniques include infrared (800 to 900cm 1) chemiluminescent analysis for kinetic studies, and chromatography for the identification and separation of peroxides in complex mixts (Refs 5,6, 7,14,15,16,17, 20 21)... 

G. Geuskens, D. Baeyens Volant, G. Delaunois, Q. Lu Vinh, W. Piret, and C. David, Photo oxidation of Polymers II. The Sensitized Decomposition of Hydroperoxides as the Main Path for Initiation of the Photo oxidation of Polystyrene Irradiated at 253.7 nm, Eur. Polym. J., 14, 299 303 (1978). 

Zhao et al. [119] carried out thermal and radiochemical grafting of acrylamide onto the surface of polyethylene and polystyrene. The effect of four different methods on the grafting efficiency was investigated, three of them involved two steps first hydroxylation/hydroperoxidation of the polymer... 

Abbreviations AD, asymmetric dihydroxylation BPY, 2,2 -bipyridine DMTACN, 1,4-dimethyl-l,4,7-triazacyclonane EBHP, ethylbenzene hydroperoxide ee, enantiomeric excess HAP, hydroxyapatite LDH, layered double hydroxide or hydrotalcite-type structure mCPBA, meta-chloroperbenzoic acid MTO, methyltrioxorhenium NMO, A-methylmorpholine-A-oxide OMS, octahedral molecular sieve Pc, phthalocyanine phen, 1,10-phenantroline PILC, pillared clay PBI, polybenzimidazole PI, polyimide Por, porphyrin PPNO, 4-phenylpyridine-A-oxide PS, polystyrene PVP, polyvinylpyridine SLPC, supported liquid-phase catalysis f-BuOOH, tertiary butylhydroperoxide TEMPO, 2,2,6,6-tetramethyl-l-piperdinyloxy TEOS, tetraethoxysilane TS-1, titanium silicalite 1 XPS, X-ray photoelectron spectroscopy. 

Photo-oxidation of citronellol in polystyrene beads [120]. A sample of 3.0 g of polystyrene beads (commercial, cross-polymerized with 1% of divinylbenzene) was treated with a solution of 2 mg of tetraphenylporphyrin and 780 mg (5 mmol) of citronellol in 20 mL of ethyl acetate in a petri-dish (30 cm diameter). After 2h in a ventilated hood, the solvent has evaporated and the petri-dish was covered with a glass plate and irradiated for 5 h with a 150 W halogen lamp. The solid support was then washed with 3 x 20 mL of ethanol, the combined ethanol fractions were rota-evaporated and 900 mg of the hydroperoxide mixture (96%) was isolated as a slightly yellow oil. The hydroperoxides were quantitatively reduced to the corresponding allylic alcohols by treatment with sodium sulfite. One of these products is used in the industrial synthesis of rose oxide. 

Another class of secondary antioxidants used in food contact plastics is thioether. The most common examples used in polypropylene, polystyrene and PVC are thiodipropanoic acid, didodecyl ester (DLTDP) and thiodipropanoic acid, dioctadecyl ester (DSTDP). Thioethers react with hydroperoxides to form sulphoxides as shown in Fig. 10.8. 

Boron-containing catalysts have also found application, with a relatively lower stereoselectivity. Cyclohexene oxides can be obtained with a selectivity of 97.5% in the H2O2-AS2O3 system. Arsonated polystyrenes have also been employed as catalysts. Epoxidation of olefins may be attained with hydroperoxide bound on an aluminium oxide surface. ... 

The new suggestion proposed for polystyrene by Rabek and BAu1>y (57) considers the formation of hydroperoxide groups along oT polymer chain from a reaction of singlet oxygen with... 

Breck at al (68) havs recently examined the reactivities of a number of saturated and unsaturated polymers towards singlet oxygen generated by microwave generator. The saturated ohain polymers as polystyrene,polyurethane and polyethylene were found to be inert within the experimental conditions with singlet oxygen,while the unsaturated polymers as poly-dienes were found to react quite readily.In this paper concentration of hydroperoxide groups has been measured. 

S. Bhaduri, H. Khwaja, Polymer-supported complexes. Part 3. Synthesis of a polystyrene-anchored molybdenum(V) dithiocarbamato-derivative and its applications in reactions involving f-butyl hydroperoxide, ]. Chem. Soc., Dalton Trans. (1983) 415. 

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