Poly sulfide properties

Superior Environmental Products, Inc. introduced a product based on liquid poly sulfide containing 40% of a surface-modified scrap tire mbber. The product, ER-IOOR, is a coating that can temporarily contain chemical, oil, and gasoline spills. Rodriguez [97] reported that an unsaturated polyester resin containing silane-treated CGR showed better mechanical properties than that containing untreated CGR. 

Crystallinity of these hexafluoroisopropylidene-unit-containing poly(ketone)s is low except for poly(sulfide ketone) (13). The water contact angle for the fluorine-containing poly(ketone) films is high, being 98° for poly(ether ketone) (11), from 2,2-bis(4-carboxyphenyl)-l,l, l,3,3,3-hexafluoropropane(15) and 96° for poly(sulfide ketone) (13) from 15, whereas it is 78° for poly(ether ketone) from 2,2-bis(4-carboxy-phenyl)propane (16) and 74° for the poly(sulfide ketone) from 16. This result indicates that the substitution of isopropylidene units of poly-(ketone)s with hexafluoroisopropylidene units has a remarkable effect on the surface properties of poly(ketone) films. 

Zhang, L., Ma, C. and Mukerjee, S. 2005. Effect of copolymer composition on the oxygen transport properties of sulfonated poly(arylene ether sulfone) and sulfonated poly(sulfide sulfone) PEMs. Journal of the Electrochemical Society 152 A1208-A1216. 

Thorium sulfide, ThSz, is obtained by the action of H2S or sulfur on thonum metal. The oxysulfide, ThOS. has been obtained in several ways, one of which is by the action of CS2 on thorium dioxide at elevated temperatures. At 800°C and under pressure, sulfur combines with thonum to yield compounds with approximately die formulas ThS, TI12S3, and TI13S7 The first two have semimetallic properties and may be employed as ceramics for use with highly electropositive metals, whereas the last appears to be a poly sulfide. 

A variety of polymers, both thermosets as well as thermoplastics, can be blended and coreacted with epoxy resins to provide for a specific set of desired properties. The most common of these are nitrile, phenolic, nylon, poly sulfide, and polyurethane resins. At high levels of additions these additives result in hybrid or alloyed systems with epoxy resins rather than just modifiers. They differ from reactive diluents in that they are higher-molecular weight-materials, are used at higher concentrations, and generally have less deleterious effect on the cured properties of the epoxy resin. 

Poly sulfide compounds that are compatible with epoxy resins are liquid elastomers at room temperature. The most significant commercial resin of this type is LP-3 from Toray. The predominant product is a mercaptan-terminated liquid polymer (LP) that contains approximately 37% bound sulfur (see Fig. 7.2). It is the high concentration of sulfur linkages that provides these products with their unique chemical properties. A sulfur odor is noticeable during processing, making ventilation important. 

Table 11.18 shows the effect of increasing the poly sulfide-epoxy ratio on impact properties the effect at concentrations of polysulfide polymer greater than 1 1 is especially significant. The combination of increased flexibility, tensile strength, and elongation is very desirable in certain adhesive applications. 

Epoxy-polysulfide systems can be formulated either as a liquid DGEBA epoxy mixed with liquid poly sulfide polymer or as an epoxy-terminated polysulfide polymer either may be cured with a tertiary amine such as DMP-30. Table 11.19 describes the formulation and shows the physical properties of these epoxy-polysulfide adhesives compared to an unmodified epoxy adhesive. 

Describe the preparation of poly(phenylene sulfide), properties, and uses. 

Applications of epoxy-polysulfide adhesives primarily include structural assemblies requiring some degree of resilience. Epoxy-poly sulfides are used in bonding concrete for floors, airport runways, bridges and other concrete structures, metals, glass and ceramics, wood, rubber, and some plastics. They are particularly durable in outdoor applications where temperature extremes (freeze-thaw cycles) will be encountered. Epoxy-poly sulfides can be heavily filled without adversely affecting their properties. 

Property ASTM Styrene polyester Epoxy Silicone Epoxy- Epoxy- Epoxy- polyurethane polysulfide polyamide (50-50, (50-50) (50-50) diamine cure) Poly- sulfide Poly-urethane-(diamine Plas-Silicone cure) tisol Prepolymer... 

However, polymer quality and cure rates were not reproducible batch to batch, and field experience showed that chemical resistance and dynamic sealant properties were inferior to those of poly sulfides. Second generation poly-mercaptans were introduced in 1974.81.82,94... 

Property Change with increase in proportion of di- and poly-sulfides... 

Epoxy poly sulfides [10] are available as two-part liquids or pastes that cure at room temperature or higher to rubbery solids that provide bonds with excellent flexibility and chemical resistance. These adhesives bond well to a number of substrates. Shear strengths and elevated-temperature properties are low, but resistance to peel and low-temperature properties are quite high. 

Because the chemical stmcture of poly(phenylene sulfide) [9016-75-5] (PPS) does not fall into any of the standard polymer classes, the Federal Trade Commission granted the fiber the new generic name of Sulfar. The fiber has excellent chemical and high temperature performance properties (see... 

Blends with good mechanical properties can be made from DMPPO and polymers with which DMPPO is incompatible if an appropriate additive, compatibilizing agent, or treatment is used to increase the dispersion of the two phases. Such blends include mixtures of DMPPO with nylon, polycarbonate, polyester, ABS, and poly(phenylene sulfide). 

Poly(phenylene sulfide) (PPS) is another semicrystalline polymer used in the composites industry. PPS-based composites are generally processed at 330°C and subsequently cooled rapidly in order to avoid excessive crystallisation and reduced toughness. The superior fire-retardant characteristics of PPS-based composites result in appHcations where fire resistance is an important design consideration. Laminated composites based on this material have shown poor resistance to transverse impact as a result of the poor adhesion of the fibers to the semicrystalline matrix. A PPS material more recently developed by Phillips Petroleum, AVTEL, has improved fiber—matrix interfacial properties, and promises, therefore, an enhanced resistance to transverse impact (see PoLYAffiRS containing sulfur). 

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