Polyphenylene sulfide , adhesives

Polyphenylene sulfide Melts at 270-315°C (578-599°F) crosslinked polymer stable to 450°C (842°F) in air adhesive and laminating applications. 

Polyphenylene sulfide parts are commonly bonded together with adhesives. A suggested surface preparation method is to solvent-degrease the substrate in acetone, sandblast, and then repeat the degreasing step with fresh solvent. The polyphenylene sulfide surface that forms next to a mold surface is more difficult to bond than a freshly abraided surface. This is possibly due to a different chemical surface structure that forms at high temperature when the resin is in contact with the metal mold surface. 

Adhesives recommended for polyphenylene sulfide include epoxies, and urethanes. Joint strengths in excess of 1000 psi have been reported for abraded and solvent-cleaned surfaces. Somewhat better adhesion has been reported for machined surfaces. The high heat and chemical resistance of polyphenylene sulfide plastics makes them inappropriate for either solvent cementing or heat welding. 

Structural adhesives must have a glass transition temperature higher than the operating temperature to avoid a cohesively weak bond and possible creep problems. Modem engineering plastics, such as polyimide or polyphenylene sulfides, have very high glass transition temperatures. Most common adhesives have a relatively low glass transition temperature so that the weakest thermal link in the joint may often be the adhesive. 

Polyimide and polyphenylene sulfide (PPS) resins present a problem in that their high-temperature resistance generally requires that the adhesive have similar thermal proper-... 

H. F. Webster and J. P. Wightman, "Effects of Oi gen and Ammonia Plasma Treatment on Polyphenylene Sulfide Thin Films and Their Interaction with Epo Adhesive," J. Adhesion Sd. Tedinol.. 5, 93-106 (1991). 

Polyimide and polyphenylene sulfide resins present a problem in that their high temperature resistance generally requires that the adhesive have similar thermal properties. Thus, hi -temperature epoxies adhesive are most often used with polyimide and PPS parts. Joint strength is superior (greater than 1000 Ib/in ) but thermal resistance is not better than the best epo3 systems (300 to 400°F continuous). 

Polyphenylene oxide (Noryl from GE) and polyphenylene sulfide (Ryton from Phillips) are used as high-temperature engineering plastics. Polyphenyl ether sulfones are manufactured by a number of companies under a variety of trade names including 720P, 220P by ICI and RADEL by Union Carbide. They are generally used as injection-moldable thermoplastics and in the adhesive and composite industry. 

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