Oxidized Poly phenylene sulfide

The sulfide moiety of PPS can be oxidized to a sulfoxide group. This effects a higher temperature stability. The oxidation has been performed as a polymer analogue reaction using acetic acid and concentrated nitric acid for 24 h at 0-5°C. However, in this process, long reaction times are required, and the attack of the aromatic rings by nitric acid may occur. 

The oxidation of PASs with ozone leads to the formation of poly(aryl-ene sulfoxide)s with a high selectivity. This reaction takes place although ozone is an extremely strong oxidant. Thus, an appropriate amount of ozone enables either to partially or completely convert the sulfur bond into the sulfoxide bond. ° The oxidation is carried out in an ozone/inert gas stream in which the ozone is present in a concentration of 2-6% by volume. The selection of the suspension medium has a decisive influence. In methylene chloride suspension, complete oxidation to the sulfoxide is achieved in a short time. 

The sulfide group in PPS can be oxidized in a mixture of glacial acetic acid, concentrated sutfijric acid, and concentrated hydrogen peroxide at 55°C within 3 h to 5deld a polymer with sulfone groups. This modified polymer is used with poly(tetrafluoroethylene) (PTFE) for composites with improved abrasion resistance. 

In an essentially similar way as in the conventional process, copolymers with phenylene and biphenylene units separated by sulfide groups have been prepared. The biphenylene unit is made up from 4,4 -diflurobiphenyl or 4,4 -dibromobiphenyl and the phenylene unit is formed from p-dichlo-robenzene. Sodium acetate and sodium hydrogen sulfide are charged in an autoclave and NMP is used as a solvent. At the end of the heating period of 150 min up to 310°C, a pressure of around 25 bar develops in the autoclave. 

A two-step process uses the synthesis of a PPS oligomer of a degree of polymerization of ca. 5 in the first step. This oligomer is coupled to 4,4 -dichlorobenzophenone to give a copolymer bearing ketone and sulfide 

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MC MDI MEKP MF MMA MPEG MPF NBR NDI NR OPET OPP OSA PA PAEK PAI PAN PB PBAN PBI PBN PBS PBT PC PCD PCT PCTFE PE PEC PEG PEI PEK PEN PES PET PF PFA PI PIBI PMDI PMMA PMP PO PP PPA PPC PPO PPS PPSU Methyl cellulose Methylene diphenylene diisocyanate Methyl ethyl ketone peroxide Melamine formaldehyde Methyl methacrylate Polyethylene glycol monomethyl ether Melamine-phenol-formaldehyde Nitrile butyl rubber Naphthalene diisocyanate Natural rubber Oriented polyethylene terephthalate Oriented polypropylene Olefin-modified styrene-acrylonitrile Polyamide Poly(aryl ether-ketone) Poly(amide-imide) Polyacrylonitrile Polybutylene Poly(butadiene-acrylonitrile) Polybenzimidazole Polybutylene naphthalate Poly(butadiene-styrene) Poly(butylene terephthalate) Polycarbonate Polycarbodiimide Poly(cyclohexylene-dimethylene terephthalate) Polychlorotrifluoroethylene Polyethylene Chlorinated polyethylene Poly(ethylene glycol) Poly(ether-imide) Poly(ether-ketone) Polyethylene naphthalate Polyether sulfone Polyethylene terephthalate Phenol-formaldehyde copolymer Perfluoroalkoxy resin Polyimide Poly(isobutylene), Butyl rubber Polymeric methylene diphenylene diisocyanate Poly(methyl methacrylate) Poly(methylpentene) Polyolefins Polypropylene Polyphthalamide Chlorinated polypropylene Poly(phenylene oxide) Poly(phenylene sulfide) Poly(phenylene sulfone)... 

Table 5.4 Abrasion Resistance of Fluoropolymer/Oxidized Poly(phenylene sulfide) Composites [32]...

Stokes, V. K., The vibration welding of poly(phenylene oxide)/poly(phenylene sulfide) blend, Polym Eng Sci, 38(12), 2046-2054,1998. 

Fig. 1. Engineering resins cost vs annual volume (11) (HDT, °C) A, polyetheretherketone (288) B, polyamideimide (>270) C, polyarylether sulfone (170- >200) D, polyimide (190) E, amorphous nylons (124) F, poly(phenylene sulfide) (>260) G, polyarylates (170) H, crystalline nylons (90—220) I, polycarbonate (130) J, midrange poly(phenylene oxide) alloy (107—150) K, polyphthalate esters (180—260) and L, acetal resins (110—140).

Montaudo and co-workers have used direct pyrolysis mass spectrometry (DPMS) to analyse the high-temperature (>500°C) pyrolysis compounds evolved from several condensation polymers, including poly(bisphenol-A-carbonate) [69], poly(ether sulfone) (PES) and poly(phenylene oxide) (PPO) [72] and poly(phenylene sulfide) (PPS) [73]. Additionally, in order to obtain data on the involatile charred residue formed during the isothermal pyrolysis process, the pyrolysis residue was subjected to aminolysis, and then the aminolyzed residue analysed using fast atom bombardment (FAB) MS. During the DPMS measurements, EI-MS scans were made every 3 s continuously over the mass range 10-1,000 Da with an interscan time of 3 s. 

Although thiophenol, like other thiols, normally forms diphenyldisulfide upon oxidation [19], in the presence of a strong proton-donor (CH3NO2/CF3COOH) it can undergo anodic polymerization to give poly-/ -phenylene sulfide (Eq. 5) [26]. 

According to the data in literatnre, poly(phenylene sulfide), polycarbonate, and polysnlfone are the most stable of the polymers studied, whereas PVC, both flexible and rigid, is the least oxidatively stable. HDPE was among the most oxidatively stable polymers under high-pressnre oxygen at 175°C [8]. 

Finally, a few articles have appeared on chemiluminescence of polymers. This technique has been used to detect hydroxy radicals in wood oxidation,y-irradiation effects on polyethylene, oxidation of nitrile-butadiene rubber, rubber under stress,antioxidant efficiencies in polyethylene, reactions of peroxy radicals, stereoregularity in poly(propylene), colour development in epoxy resins and structural changes in thermally aged poly(phenylene sulfide). ... 

In general, regularity in polymer structure and strong intermolecular forces favor high T values. Phenylene groups, such as those in polyphenylene, poly-p-phenylene oxide (PPO), and poly-/>-phenylene sulfide (PPS), increase T values. 

In polymers such as polybhenylenes there are a few aliphatic linkages and many aromatic rings which account for their improved heat resistance. Several polyphenylenes are shown in Figure 1.37. Poly (phenylene oxide) has excellent dimensional stability at elevated temperatures. Repeated steam autoclaving does not deteriorate its properties. Poly(phenylene sulfide) is completely nonflammable. It is used in the form of composites with both asbestos and glass fibers. 

Poly(phenylene sulfide) (PPS) is the thio analogue of poly(phenylene oxide) (PPO) [57]. The first commercial grades were introduced by Phillips Petroleum in 1968 under the trade name Ryton. Other manufacturers also have introduced PPS (e.g., Tedur by Bayer). The commercial process involves the reaction of p-dichlorobenzene with sodium sulfide in a polar solvent. 

The chemical structures of sulfonated poly(4-phenoxybenzoyl-l,4-phenyl-ene) (S-PPBP) (1), poly(p-xylylene) (S-PPX) (2), poly(phenylene sulfide) (S-PPS) (3), poly(phenylene oxide) (S-PPO) (4), poly(ether ether ketone) (S-PEEK) (5), poly(ether ether sulfone) (S-PEES) (6), arylsulfonated poly(ben-zimidazole) (S-PBl) (7) sulfonated polyphenylquinoxiiline (S-PPQ) (8) and sulfonated phenoxy polyperyleneimide (PSPPI) (9) are shown below. ACPs are sulfonated using common sulfonating agents [82-85]. In particular, PEEK can be sulfonated in concentrated sulfuric acid [50], chlorosulfonic acid [86], SO3 (either pure or as a mixture) [53,65,86,87], a mixture of methanesulfonic acid with concentrated sulfuric acid [88] and acetyl sulfate [89,90]. 

In the first step, a sulfonated poly(phenylene sulfide sulfone) is formed, which is then oxidized with hydrogen peroxide to the corresponding sulfonated poly(phenylene sulfone). The method of condensation has been optimized [34]. Polymers with high... 

Poly(phenylene sulfide) (PPS) has been synthesized by oxidative polymerization of diphenyl disulfide, which was obtained via oxidation of thiophenol (eq. 8) (198-208). PPS is an engineering plastic with a high melting point, which is manufactured by condensation polymerization eliminating a salt. 

The synthesis of poly(phenylene oxides) and poly(phenylene sulfides) coordinated to pentamethylcyclopentadienylruthenium cations was described by Segal and Dembek. Dembek and coworkers found that these polymers behaved like polyelectrolytes in polar organic solvents. The trichlorobenzene and tetrachloroben-zene complexes were useful in the preparation in highly branched oiganometallic complexes. ... 

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