Polypropylene sulphide

Some cadmium compounds, including simple salts, were revealed to be excellent catalysts for the enantiosymmetric polymerisation of propylene sulphide [156,157], For instance, the proportion of isotactic diads in the polypropylene sulphide) sample obtained in polymerisation with the cadmium (7 )-tartrate catalyst was more than 95%, higher than the 69% which was characteristic of a polymer sample prepared using the zinc (i )-tartrate catalyst [158]. The superior stereoselectivity of the cadmium (i )-tartrate catalyst is also borne out by the more effective separation into fractions having opposite optical rotations of the polypropylene sulphide) yielded by cadmium tartrate, compared with that yielded by zinc (i )-tartrate. Note the quite different behaviour of these two catalysts in terms of their stereoelectivity in the polymerisation of propylene sulphide only very slight optical activity was found for the polypropylene sulphide) sample prepared using cadmium tartrate, whereas that associated with the polymer sample obtained with zinc tartrate was found to have a much higher value [158]. 

An interesting paper has reported the absorption of heavy metal salts such as H[AuCl4] by cotton fabrics containing polyethylene (and polypropylene) sulphide functional groups. Such fabrics may have practical application as filters for the removal of heavy metals from aqueous solution. 

Poly(ethylene terephtlhalate) Phenol-formaldehyde Polyimide Polyisobutylene Poly(methyl methacrylate), acrylic Poly-4-methylpentene-1 Polyoxymethylene polyformaldehyde, acetal Polypropylene Polyphenylene ether Polyphenylene oxide Poly(phenylene sulphide) Poly(phenylene sulphone) Polystyrene Polysulfone Polytetrafluoroethylene Polyurethane Poly(vinyl acetate) Poly(vinyl alcohol) Poly(vinyl butyral) Poly(vinyl chloride) Poly(vinylidene chloride) Poly(vinylidene fluoride) Poly(vinyl formal) Polyvinylcarbazole Styrene Acrylonitrile Styrene butadiene rubber Styrene-butadiene-styrene Urea-formaldehyde Unsaturated polyester... 

Propylene sulphide was found [246] to undergo copolymerisation with carbon dioxide in the presence of the triethylaluminium pyrogallol (2 1) catalyst, yielding copolymers, polypropylene thioether-monothiocarbonate)s, containing propylene thiocarbonate units in an amount reaching 42 mol.-%, apart from the predominating propylene sulphide units (Table 9.4) ... 

Poly(phenylene sulphide) Polypropylene Polystyrene toughened with rubber Styrene-acrylonitrile... 

Especially above room temperature many polymers degrade in an air atmosphere by oxidation that is not light-induced (heat ageing). A number of polymers already show a deterioration of the mechanical properties after heating for some days at about 100 °C and even at lower temperatures (e.g. polyethylene, polypropylene, poly(oxy methylene) and poly(ethylene sulphide)). 

Photoactive Additives.—Ferric compounds, in particular, the chloride, continue to attract much interest as photosensitizers for thermoplastics. " From e.s.r. work the mechanism appears to involve a redox reaction resulting in the formation of active hydroxy-radicals. Photodegradable polyethylene film has been developed by doping it with radiation-modified atactic polypropylene and hydroxyethyl-ferrocene. Several workers have studied the dye-sensitized photo-oxidation of polyisoprene and di-n-butyl sulphide embedded in Augustyniak and... 

Notched Izod impact strength tests have been conducted on the effect of fiber length in a nylon 6/6 compound reinforced with 50 wt% glass fiber. It shows that impact strength of reinforced TPs (RTPs) increases significantly, as fiber length is increased. Similar effects have been measmed with other fibers, such as aramid and carbon, and with other matrices, such as polypropylene and polyphenylene sulphide. 

The theory has shown that an improvement of some 50% in mechanical properties should be produced by increasing fiber length from 0.3 mm to 2 mm. Several producers and specialist compounders of TPs have long fiber technology using nylons, polypropylenes, TP polyesters, and polyphenylene sulphide (PPS). 

Examples of resins used include the nylon family (polyamide/PA), polypropylene (PP), polystyrene, and polyethylene. There continues to be growing applications for the higher-performance RTFs, such as polyphenylene sulphide (PPS) and polysulphone (PSU). Use is made of many other TPs (Chapter 3). 

The process can combine conventional glass fiber roving, aramid, or carbon fiber tows with TPs, most commonly polyethylene terephthalate (PET) and nylon (polyamide/PA). Other plastics used include polyphenylene sulphide (PPS), styrene-maleic anhydride (SMA), high-density polyethylene (HDPE), and polypropylene (PP). The TPs can take the form of pellets, chips, chunks, or shreds, and as the process uses hot-melt injection, no solvents or two-part systems are involved. Additives such as colorants and fillers can be used as required. 

Journal of Applied Polymer Science 60, No.l, 4th April 1996, p.29-35 STUDY OF DIFFUSION AND SORPTION OF BIS-(2-CHLOROETHYL)SULPHIDE (SM) AND BIS-(2-CHLOROETHYL)ETHER (OM) THROUGH POLYPROPYLENE (PP) AND BIAXIAL-ORIENTED POLYPROPYLENE (BOPP) FILMS BY THE FTIR-ATR SPECTROSCOPIC METHOD Semwal R P Baneijee S Chauhan L R Bhattacharya A Rao N B S N... 

POM Polyoxymethylene PPBC Polypropylene block copolymer PPHP Polypropylene homopolymer PPS Polyphenylene sulphide PPO Polyphenylene oxide PS Poly styrene... 

Heterogeneous Polythene, polypropylene, silicone rubber etc. with various halide, sulphate, phosphate, sulphide or oxalate precipitates form membranes for Ba, SO4, PO4, X, S etc. PTFE + graphite with ionic compounds for range of ions. 

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