Analysis of polyphenylene sulfide

Figure 1. Differential thermal analysis of polyphenylene sulfide in nitrogen...

Figure 1. Differential thermal analysis of polyphenylene sulfide in nitrogen. Sample A melted under nitrogen and quenched before DTA. Sample B heated at 370°C in air 4 hrs and quenched before DTA. Heating ratet 10° C /minute.

Our analysis says that no company is making an acceptable profit in this business today. The problems are too many competitors, too many materials, products too expensive to produce, and markets too small. And yet new products keep emerging. Polyphenylene sulfide s volume is about one-quarter of that total. Will polyphenylene sulfide emerge from the pack to become a profitable business The next few years should answer the question. It s been a slow start for polyphenylene sulfide. It s taken over twenty years from the initial commercialization of polyphenylene sulfide to reach a global sales volume of around 20 million pounds. There are already eight competitors globally and a great deal of excess capacity. 

Nam and coworkers [27] used dynamic mechanical analysis to measure the heat distortion temperature of polyphenylene sulfide/acrylonitrile-butadiene styrene. 

In the Phillips process, polyphenylene sulfide (PPS) is obtained from the polymerization mixture in the form of a fine white powder, which, after purification, is designated Ryton V PPS. Characterization of this polymer is complicated by its extreme insolubility in most solvents. At elevated temperatures, however, Ryton V PPS is soluble to a limited extent in some aromatic and chlorinated aromatic solvents and in certain heterocyclic compounds. The inherent viscosity, measured at 206°C in 1-chloronaphthalene, is generally 0.16, indicating only moderate molecular weight. The polymer is highly crystalline, as shown by x-ray diffraction studies (9). The crystalline melting point determined by differential thermal analysis is about 285°C. 

Polyphenylene sulfide is a partially crystalline polymer featuring an aromatic ring bridged by sulfur atoms in the 1,4-positions, as shown below. The form presented has the trade name of Ryton. Sample preparation of this material can be difficult, and the traditional KBr pellet method produces a poor-quality spectrum with Christiansen-type distortion (see Fig. 44b). A Csl pellet may be used instead to obtain an improved IR spectrum, suitable for quantitative analysis (see Fig. 44a). This polymer is usually used in conjunction with structural reinforcement additives, such as glass fibers or fillers such as PTFE (Teflon), and caution is necessary when attempting... 

The heat distortion temperature at 1.80 Mpa is the temperature that causes a beam loaded to 1.80 to deflect by 0.3 mm. If the heat distortion temperature is lower than the ambient temperature, -20 C is given. Polymers such as low-density polyethylene, styrene ethylene-butene terpolymer, ethylene-vinyl acetate copolymer, polyurethane, and plasticized polyvinyl chloride distort at temperatures below <50°C, whereas others, such as epoxies, polyether ether ketone, polydiallylphthalate, polydiallyl isophthalate, polycarbonate, alkyd resins, phenol formaldehyde, polymide 6,10 polyimide, poly-etherimides, polyphenylene sulfide, polyethersulfone, polysulfonates, and silicones, have remaikably high distortion temperatures in the range of 150°C to >300 C. Thermomechanical analysis has been used to determine the deflection temperature of polymers and sample loading forces (i.e., plots of temperature vs. flexure). 

The tiiermal properties of the para-, meta-, and ort/jo-substituted polyphenylene sulfides (8a-c, 9a-c) were examined using thermogravimetric analysis. Although all of these polymers exhibited good thermal stability, TGA results indicated that the thermal stabfiity of tiiese polymers decreased in the order p-> m-> o-. For example, the onsets for weight loss in polymers 9a-c were 512,491, and 448°C, respectively. 

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