Reference

Evaluation of the permanent set of injection molded circular-section gasket rings from nitrile rubber during long-term compression

Evaluation of the permanent set of injection molded circular-section gasket rings from nitrile rubber during long-term compression. Trejbal, Jiri; Pejskar, Jiri (Rubena, N. P., Nachod, Czech.). Plasty Kauc., 20(5), 132-6 (Czech) 1983. CODEN: PLKCAS. ISSN: 0322-7340. DOCUMENT TYPE: Journal CA Section: 39 (Synthetic Elastomers and Natural Rubber) Compression set of nitrile rubber-based gasket O-rings depended primarily on the type of vulcanizing agent, but also on vulcanization temp., vulcanization time, and addnl. thermal treatment of the vulcanizates. Under optimum vulcanizing conditions, dimorpholine disulfide [103-34-4]-vulcanized gasket rings exhibited the lowest permanent set, followed by gaskets vulcanized with peroxides (dicumyl peroxide [80-43-3], a,a'-bis-tert-butylperoxydiisopropylbenzene [25155-25-3], 2,5-dimethyl-2,5-di-tert-butylperoxyhexane [78-63-7], thiuram [137-26-8], and S. At proper vulcanization degree, the permanent set of the gasket rings was not affected by the injection molding technol.

Ion exchange membranes

Ion exchange membranes. Tamura, Yorikazu; Hayashi, Yuzuru; Nose, Yoshinori; Negishi, Sutemi (Teijin, Ltd., Japan). Japan. Kokai JP 51145482 14 Dec 1976 Showa, 10 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: C08J005-22. APPLICATION: JP 75-69145 10 Jun 1975. DOCUMENT TYPE: Patent CA Section: 37 (Plastics Fabrication and Uses) Ion exchangers having good resistance to chems. and heat were prepd. 27029-05-6 and 25067-11-2 which are cas registry numbers are also used here. from blends of propylene-tetrafluoroethylene copolymer (I) [27029-05-6] with hexafluoropropylene-tetrafluoroethylene copolymer (II) [25067-11-2] and sulfonated divinylbenzene-styrene copolymer (III) [9003-70-7] and optionally crosslinked with 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane [78-63-7]. Thus, a mixt. of water 500, styrene 100, divinylbenzene 50, Na lauryl sulfate 4, Na bisulfite 1.5, and Na pyrophosphate 1 part was heated to 70.degree., mixed with 1.5 parts (NH4)2S2O8, and polymd. for 4 h to prep. III, which (40 parts) was dispersed in 400 parts CHCl3, treated with 60 parts chlorosulfonic acid for 3 h to prep. sulfonated III, mixed (50 parts) with 50 parts each I and II, and used to prep. an ion exchanger. .