Polypropylene zinc oxide

All commercial materials are based on calcium hydroxide and liquid alkyl salicylates (Prosser, Grolfman Wilson, 1982) and are supplied as a two-paste pack. Zinc oxide is sometimes added to the calcium hydroxide, as are neutral fillers. A paste is formed from this powder by the addition of a plasticizer examples include A-ethyl toluenesulphonamide (o- orp-) and paraffin oil, with sometimes minor additions of polypropylene glycol. The other paste is based on an alkyl salicylate as the active constituent containing an inorganic filler such as titanium dioxide, calcium sulphate, calcium tungstate or barium sulphate. Alkyl salicylates used include methyl salicylate, isobutyl salicylate, and 1-methyl trimethylene disalicylate. An example of one commercial material, Dycal, is given in Table 9.7, but its composition has been subjected to change over the years. 

A polypropylene filter, which contained zinc oxide, reacted explosively in contact with chlorine and was destroyed. This filter was tested at 300 bar. Zinc chloride, which is formed by the effect of chlorine on zinc oxide, may have catalysed this reaction. 

Zhao, H. and H, R.K.Y. (2006) A study on the photo-degradation of zinc oxide (ZnO) filled polypropylene nanocomposites. Polymer, 47,3207-3217. 

In a review of incidents involving explosive reactivity of liquid chlorine with various organic auxiliary materials, two involved hydrocarbons. A polypropylene filter element fabricated with zinc oxide filler reacted explosively, rupturing the steel case previously tested to over 300 bar. Zinc chloride derived from the oxide may have initiated the runaway reaction. Hydrocarbon-based diaphragm pump oils or metal-drawing waxes were violently or explosively reactive [8], A violent explosion in a wax chlorination plant may have involved unplanned contact of liquid chlorine with wax or chlorinated wax residues in a steel trap. Corrosion products in the trap may have catalysed the runaway reaction, but hydrogen (also liberated by corrosion in the trap) may also have been involved [9],... 

The zinc-air treatment is somewhat simpler because the absence of manganese dioxide means that the acid treatment is not necessary. After the batteries have been opened, they are immersed in sodium hydroxide within a trummel. The fines, containing zinc powder, zinc oxide, carbon and lime are suspended in solution and undergo the same zinc treatment as described above. After washing, the large fraction consisting of polypropylene pieces, steel and carbon are sorted and recycled within specialist industries. 

Flamtard S Tin zinc oxide (SnZnOs). Flame retardant for PVC, polychloroprene, chlorosulfonated polyethylene, polypropylene, other halopolymers. White powder d = 3.4 dec 180° soluble in strong acids and bases LDso (rat orl) > 5000 mgikg, (rat der) > 2466 mg/kg. Alcan Chem. Atomergic Chemetals Blythe, Williams Ltd, Joseph Storey. 

Contents v. 1. Acetaminophen through Dimethyl ketone- v. 2. Ethyl acetate through Polypropylene - v. 3. Polysiloxane through Zinc oxide. 

Isotactic polypropylene composites with tetra-needle-shaped zinc oxide whisker were prepared via melt blending in a twin-screw extruder. The whisker is a p-nucleating agent, which offers higher crystallization temperature, smaller sphemlites, and faster crystalhzation rate than can be obtained in neat iPP. The addition of whisker also increases heat deflection temperature and thermal degradation temperature of iPP composite. ... 

Shuhua He, Jianping Zhou, Wanli Fu. Study on electroconductivity of tetragonal zinc oxide whisker (T-ZnOW)/polypropylene composite. Fine and Specialty Chemicals, 15(ll) 29-32, 2007. 

Additives used in finai products Fillers aluminum oxide, calcium carbonate, clay, carbon black, ferrite, graphite, magnesium oxide, nanocellulose, sand, silica, titanium dioxide, zinc oxide, zirconia Plasticizers benzyl butyl phthalate, dipropylene glycol dibenzoate, glycerin, monostea-ryl citrate, polyethylene and polypropylene glycols, triacetin Antistatics alkyl aryl sulfonate, cadmium sulfide, ethoxylated fatty acid amine, tetraammonium salt Antiblocking talc Release silane modified PVOH Slip PTFE beads Crosslinkers Defoamers ... 

Zinc oxide is a crystalline, odorless, and white or yellowish white powder. It absorbs carbon dioxide from the air, has high UV absorption, and is used as an antiseptic additive. It is insoluble in water and alcohol but soluble in acid, ammonium carbonate and alkali hydroxide solutions. Zinc oxide is used as a filler and accelerator-activator in rubber and plastics. It improves resistance to weathering when used with polypropylene, promotes hardness, flame retardant, and electrical conductivity to polymers, and has been used in silicones, polyesters, and polyolefins. 

Lee et al. explored the application of zinc oxide nanoparticles to polypropylene nonwoven fabrics via electrospinning as one approach to impart UV-protective properties. In addition, moisture and air vapor transport characteristics of layered clothing systems with various levels of electrospun mat area density are assessed to observe the consequence of electrospun web layers on thermal comfort level of the layered structures (Fig. 14.6c) [56]. Ultrafine cellulose fibers from natural cotton lines, whose degree of polymerization was above 10,000, were electrospun. The cellulose nanotibers treated with the hydrothermal incorporation of Ce02 nanoparticles into the nanofiber substrate surface showed good UV-shielding properties... 

Cullis and Hirschler (33) found that zinc acetylacetonate and cobalt acetyla-cetonate at 1% in polypropylene afforded self-extinguishing properties by the ASTM D635 test (Table TV). These additives appear to be catalytic pro-oxidants which enhanced the carbon yield. 

The crystalline fraction was found to be formed via a cleavage of the C1g-0(CH2—O) bond in the monomer molecule and proved many years ago to be an isotactic polymer (with regular head-to-tail linkages) (Figure 9.1) [42]. The structure of the amorphous fraction, on the other hand, varies depending on the kind of catalyst. Some amorphous polypropylene oxide)s prepared with catalysts such as diethylzinc-methanol [43] or aluminium isopropoxide-zinc chloride [44] consist of regular head-to-tail linked units, but they are atactic (the mole fraction of isotactic diads is less than 0.6) [43]. Some other amorphous polypropylene oxide)s obtained with catalysts derived from reactions in the diethylzinc-water [44,45], and triethylaluminium-water [46] systems, and with aluminium isopropoxide [44], have been found to be irregular, i.e. to contain head-to-head and tail-to-tail enchained monomer units. 

This paper describes the theory which permits us to characterize adequately the stereosequence length in stereoregular polymers from the equilibrium percent crystallinity at room temperature and from the melting points of the polymers. Results based on this theory are given on the characterization of the isotactic stereosequence length in the crystalline fractions of polypropylene oxide polymers made from the following catalyst systems (a) ferric chloride (17, 19) (b) diethyl zinc-water (10) (c) diethyl zinc-water-isopropylamine (d) diethyl zinc-water-cyclohexylamine (14). 

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