Polystyrene/polyphenylene

Polyphosphazenes and cyclophosphazenes are almost unique as carrier molecules for transition metals because of the wide range of binding sites that can be incorporated into the phosphazene structure. The substitutive mode of synthesis described earlier allows a structural diversity that is not found, for example, in polystyrene, polyphenylene oxide, or other organic carrier polymers. 

General Purpose Polystyrene lmp>act Polystyrene Polyphenylene Sulfide Polypropylene... 

General Purpose Polystyrene Impact Polystyrene Polyphenylene Sulfide SAN Copolymer... 

This review summarizes our work at the University of Bayreuth over the last few years on improving the electret performance of the commodity polymer isotactic polypropylene (Sect. 3) and the commodity polymer blend system polystyrene/polyphenylene ether (Sect. 4) to provide electret materials based on inexpensive and easily processable polymers. To open up polymer materials for electret applications at elevated temperatures we concentrated our research on commercially available high performance thermoplastic polyetherimide resins and synthesized several fluorinaled polyetherimides to identify structure-property relations and to improve further the performance at elevated temperatures (Sect. 5). 

Reprinted from Polymer, Volume 23, M. Kryszewski, B. Wandelt, D.J.S. Birch, R.E. Imhof, A.M. North and R.A. Pethrick, Photo-energy transfer in polystyrene-polyphenylene oxide blends, 926, copyright 1982, with permission... 

Blends are physical mixtures of pol5uners rather than monomers. Like copolymers, properties and processing characteristics are often very different from those of the component polymers and also vary with the ratio of components. Unlike copolymers, blend properties can be sensitive to processing conditions. Miscible blends mix on a molecular level to produce a single phase and exhibit a single transition temperature that corresponds to the blend composition. The most important commercial miscible blend is polystyrene-polyphenylene... 

Solvent bonding is suitable for all amorphous plastics. It is used primarily on ABS, acrylics, cellulosics, polycarbonates, polystyrene, polyphenylene oxide, and vinyls. Solvent welding is not suitable for crystalline thermoplastics. It is not effective on polyolefins, fluorocarbons, or other solvent-resistant polymers. Solvent welding is moderately effective on nylon and acetal polymers. Solvent welding cannot be used to bond thermosets. 

The DD/CP/MAS C-NMR spectrum of blend of polystyrene/polyphenylene oxide at 27 C. Assignments are indicated in the figure. 

In polymers such as polystyrene that do not readily undergo charring, phosphoms-based flame retardants tend to be less effective, and such polymers are often flame retarded by antimony—halogen combinations (see Styrene). However, even in such noncharring polymers, phosphoms additives exhibit some activity that suggests at least one other mode of action. Phosphoms compounds may produce a barrier layer of polyphosphoric acid on the burning polymer (4,5). Phosphoms-based flame retardants are more effective in styrenic polymers blended with a char-forming polymer such as polyphenylene oxide or polycarbonate. 

Triphenyl phosphate [115-86-6] C gH O P, is a colorless soHd, mp 48—49°C, usually produced in the form of flakes or shipped in heated vessels as a hquid. An early appHcation was as a flame retardant for cellulose acetate safety film. It is also used in cellulose nitrate, various coatings, triacetate film and sheet, and rigid urethane foam. It has been used as a flame-retardant additive for engineering thermoplastics such as polyphenylene oxide—high impact polystyrene and ABS—polycarbonate blends. 

The uses of blends of polystyrene with the so-called polyphenylene oxide polymers are discussed in Chapter 21. 

The main experimental techniques used to study the failure processes at the scale of a chain have involved the use of deuterated polymers, particularly copolymers, at the interface and the measurement of the amounts of the deuterated copolymers at each of the fracture surfaces. The presence and quantity of the deuterated copolymer has typically been measured using forward recoil ion scattering (FRES) or secondary ion mass spectroscopy (SIMS). The technique was originally used in a study of the effects of placing polystyrene-polymethyl methacrylate (PS-PMMA) block copolymers of total molecular weight of 200,000 Da at an interface between polyphenylene ether (PPE or PPO) and PMMA copolymers [1]. The PS block is miscible in the PPE. The use of copolymers where just the PS block was deuterated and copolymers where just the PMMA block was deuterated showed that, when the interface was fractured, the copolymer molecules all broke close to their junction points The basic idea of this technique is shown in Fig, I. 

Fig. 11. Effect of polyolefin primers on bond strength of ethyl cyanoacrylate to plastics. All assemblies tested in accordance with ASTM D 4501 (block shear method). ETFE = ethylene tetrafluoroethylene copolymer LDPE = low-density polyethylene PFA = polyper-fluoroalkoxycthylene PBT = polybutylene terephthalate, PMP = polymethylpentene PPS = polyphenylene sulfide PP = polypropylene PS = polystyrene PTFE = polytetrafluoroethylene PU = polyurethane. From ref. [73].

These results demonstrate some interesting chemical principles of the use of acrylic adhesives. They stick to a broad range of substrates, with some notable exceptions. One of these is galvanized steel, a chemically active substrate which can interact with the adhesive and inhibit cure. Another is Noryl , a blend of polystyrene and polyphenylene oxide. It contains phenol groups that are known polymerization inhibitors. Highly non-polar substrates such as polyolefins and silicones are difficult to bond with any technology, but as we shall see, the initiator can play a big role in acrylic adhesion to polyolefins. 

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... 

Cellulose Esters Epoxy Resins Lignins Polystyrene Poly (2-vinyl pyridine) Polyvinyl Chloride Polymethyl methacrylate Polyphenylene Oxide Phenolics Polycarbonate Polyvinyl Acetate, etc. Polyvinyl butyral SBR rubber, etc., etc. 

PP-g-AA - acrylic acid grafted polypropylene PP-g-MAH - maleic anhydride grafted polypropylene PPacr - acrylic acid grafted polypropylene PPmal - maleic anhdride grafted polypropylene PPS - polyphenylene sulfide PS - polystyrene... 

Polyolefines, polyesters, polycarbonates, polystyrene, polysulphone, polysulphone, polyphenylene oxide and polymethylinethacrylate... 

The advances in polymer blending and alloying technology have occurred through three routes (1) similar-rheology polymer pairs, (2) miscible polymers such as polyphenylene oxide and polystyrene, or (3) interpenetrating polymer networks (IPNs). All these systems were limited to specific polymer combinations that have an inherent physical affinity for each other. However with... 

Polyphenylene oxide/polystyrene Processability, lower cost... 

Odor and taste Polystyrene, styrene-acrylonitrile, polyethylene, acrylic, ABS, polysulfone, EVA, polyphenylene oxide, and many other TPs are examples of satisfactorily odor-free. FDA approvals are available for many of these plastics. Food packaging and refrigerating conditions will also eliminate certain plastics. There are TPs and melamine as well as urea compounds that are suitable for this service. 

Table 3. Flame Retarding 40/60 Polyphenylene Oxide / High Impact Polystyrene Blend...

Many of the commercially important plastics such as polystyrene, polyamide, polyester, polycarbonate, polysulfone, polyphenylene oxide alloys, epoxy, and phenolics lack good impact... 

An efficient flame retardant effect was demonstrated with 2-mil zinc coatings on polyphenylene oxide-polystyrene blends (Notyl) by Nelson (21). The action may relate to enhanced char formation by chemistry specific to this blend. However, other metal coatings on some other polymers also appeared to contribute a measurable flame retardant effect. 

Commercial examples are notably PVC-ABS blends and the blends of polyphenylene oxide with polystyrene. In the case of PPO-PS blends, it has been shown that the good char forming ability of the PPO greatly helps flame... 

Extraordinary effectiveness has also been claimed for iron halides in polyphenylene oxide/polystyrene blends (40/60 to 60/40 (31), but much of the work on low concentration additives to date has been devoted to polycarbonates. 

Modified-polyphenylene oxide (or ether) is a blend of high impact polystyrene (PS) and polyphenylene oxide (PPO), plus thermal stabilizers and a triarylphosphate flame retardant. Studies of the mechanism of the flame retardant in modified-polyphenylene oxide have shown some evidence for both solid phase and vapor phase inhibition (4). Indeed, one is always interested to know whether flame retardant action is on the solid or vapor phase. 

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