Butyl bladders

Methylol-terminated para-alkyl-substituted phenol formaldehyde resin is used as the vulcanizing agent for compounds based on butyl and EPDM rubber. The alkyl group is usually octyl. It is commonly used to cure butyl rubber where superior heat resistance is needed. Therefore, this vulcanizing agent is commonly used as the curative to make butyl bladders for repetitive curing of tires. It is also sometimes used in dynamic vulcanization with a tin chloride activator to make thermoplastic vulcanizates (TPVs). 

Quinone dioximes, alkylphenol disulfides, and phenol—formaldehyde reaction products are used to cross-link halobutyl mbbers. In some cases, nonhalogenated butyl mbber can be cross-linked by these materials if there is some other source of halogen in the formulation. Alkylphenol disulfides are used in halobutyl innerliners for tires. Methylol phenol—formaldehyde resins are used for heat resistance in tire curing bladders. Bisphenols, accelerated by phosphonium salts, are used to cross-link fluorocarbon mbbers. 

Butyl and Halobutyl Rubber. Butyl mbber is made by the polymerization of isobutylene a small amount of isoprene is added to provide sites for curing. It is designated HR because of these monomers. Halogenation of butyl mbber with bromine or chlorine increases the reaction rate for vulcanization and laminates or blends of halobutyl are feasible for production of mbber goods. It is estimated that of the - 100 million kg of butyl (UR) and halobutyl (HIIR) mbber in North America, over 90% is used in tire apphcations. The halogenated polymer is used in the innerliner of tubeless tires. Butyl mbber is used to make innertubes and curing bladders. The two major suppHers of butyl and halobutyl polymers in North America are Exxon and Bayer (see ELASTOLffiRS,SYNTHETIC-BUTYLrubber). 

Resin Cure. Resin cure systems yield carbon—carbon cross-links and, consequendy, thermally stable materials. Butyl mbber vulcanised with resins are used as tire-curing bladders, and have a life of 300—700 curing cycles at steam temperature of 175°C at about 20 m/cycle. 

Laham S, Long G, Broxup B. 1985. Induction of urinary bladder hyperplasia in Sprague-Dawley rats orally administered Tri-n-butyl Phosphate. Archives of Environmental Health 302-301-306. 

The main applications of butyl rubber are in wire and cable applications, inner tubes, inner liners in tubeless tyres, tyre curing bladders, and pharmaceutical closures, the latter utilising the low... 

PP/TTR-V consumer goods requiring low permeability to moisture, air and oxygen, competing with butyl rubber for example, inner tubes for bikes, bladders for balloons... 

Tatematsu M, Miyata Y, Mizutani M, et al. 1977. [Summation effect of N-butyl-n(4-hydroxybutyl)nitrosamine,N-(4-(5-nitro-2-furyl)-2thiazoly) formamide, N-2-fluoroenylacetanide, and 3,3 -dichlorobenzidine on urinary bladder carcinogenesis in rats.] Jarm 68 193-202. (Japanese)... 

The concentrations of 16 constituents of male mouse urine vary with the male s dominance status. Dihydrofurans, ketones, and acetates decreased in subordinates. Two sesquiterpene compounds, a- and /3-farnesene, are elevated in dominants urine 1 week after establishing dominance. The bladder or voided urine of dominants contains more 2-5ec-butyl-4,5-dihydrothiazole. Four compounds depend on hormones a- and /5-farnesene, dehydro-exo-brevicomin, and 2-5cc -butyl-4,5-dihydrothiazole. The latter two are absent in urine of immature or castrated males, and testosterone treatment restores their presence. In addition, a-and /3-farnesene do not occur in urine of immature males and are merely reduced in urine of castrates. They are not found in bladder urine and originate in the preputial glands (Harvey etal., 1989). While subordinate male mice have reduced levels of farnesenes, levels of their major urinary proteins remain high (Malone etal, 2001). 

Hagiwara, A., Tamano, S., Ogiso, T, Asakawa, E. Fukushima, S. (1990) Promoting effect of the peroxisome proliferator, clofibrate, but not di(2-ethylhexyl)phthalate, on urinary bladder carcinogenesis in F344 rats initiated by A-butyl-A-(4-hydroxybutyl)nitrosamine. Jpn. J. Cancer Res., 81,1232-1238... 

Miyata, Y, Fukushima, S., Hirose, M., Masui, T. Ito, N. (1985) Short-term screening of promoters of bladder carcinogenesis in V-butyl-V-(4-hydroxybutyl)nitrosamine-initiated, unilaterally ureter-ligated rats. Jpn. J. Cancer Res. (Gann), 16. 828-834... 

Okajima, E., Tsutsumi, M., Ozono, S., Akai, H., Denda, A., Nishino, H., Oshima, S., Sakamoto, H., and Konishi, Y. 1998. Inhibitory effect of tomato juice on rat urinary bladder carcinogenesis after N-butyl-N-(4hydroybutyl) nitrosamine initiation. Jpn. J. Cancer Res. 89, 22-26. 

The permanent positive charge of QTA influences distribution in vivo and prevents passage of blood-brain barrier and blood-cerebrospinal fluid barrier [30, 31]. Myolitic QTA are muscarinic receptor antagonists but allow a better therapeutic index as they are insoluble in lipids and thus poorly systemically absorbed (e.g. bioavailability of A-butyl-scopolamine after oral intake <1 % [30]). Therefore, spasmolytic activity in the GIT (by, e.g. cimetropium, butropium or /V-butyl-scopolamine, Fig. 1), respiratory tract (ipratropium, Fig. 1) and overactive bladder (trospium, Fig. 1) appears as the primary local effect whereas systemic side effects are markedly minimized or absent [32-34],... 

Synthetic 13-m-retinoic acid not only inhibited the incidence but also reduced the severity of bladder neoplasms induced by the intravesical administration of MNU of female Wister-Lewis rats [113]. In an experimental model with mice treated with TV-butyl-A -(4-hydroxybutyl)-nitrosamine (OH-BBN), retinoic acid (Re5), 13-cw-retinoic acid, and retinol acetate (Re2) show chemopreventive activity. In addition, a quite large number of synthetic -alkyl amide derivatives of Re2 have a greater activity to toxicity ratio than 13-cw-retinoic acid [113]. 

Urinary bladder tumors (iV-butyl-N-(4-hydroxybutyl)nitrosamine-induced rat model) [42]... 

Grubbs CJ, Moon RC, Squire RA, Farrow GM, Stinson SF, Goodman DG, Brown CC, Sporn MB. 13-cis-retinoic acid inhibition of bladder carcinogenesis induced in rats by A-butyl-A-(4-hydroxybutyl)nitrosamine. Science 1977 198 743-4. 

The most important characteristics of butyl rubber are its low permeability to air and its thermal stability. These properties account for its major uses in inner tubes, tire inner liners, and tire curing bladders. Because of the poor compatibility of butyl with other rubbers (with respect to both solubility and cure), the halobutyls are preferred. The brominated p-methylstyrene-containing butyl rubbers are used in a number of grafting reactions for tire applications and adhesives. Other uses for butyl rubber are automotive mechanical parts (due to the high damping characteristics of butyl), mastics, and sealants.55... 

Promoters appear to have a relatively high tissue specificity. Thus, phenobarbital functions as a promoter for rodent liver neoplasia but not urinary bladder neoplasia. Saccharin, on the other hand, promotes urinary bladder neoplasia but not liver neoplasia in the rat. Similarly, 12-o-tetradecano-ylphorbol-13-acetate (phorbol ester) is a potent skin and forestomach neoplasm promoter in the laboratory rodent but has no appreciable activity in the liver. Other agents, such as the antioxidants 3-t-butyl-4-methoxyphenol and 2,6-di-t-butyl-4-met-hoxyphenol, may act as promoters in one organ and antipromoters in another and have no effect in a third organ. Thus, the practical definition of a promoter must include the designation of the susceptible tissue. 

Sakata, T., Shirai, T., Fukushima, S., Hasegawa, R., and Ito, N., Summation and synergism in the promotion of urinary bladder carcinogenesis initiated by N-butyl-N-(4-hydroxybutyl)-nitrosamine in F344 rats, Gann, 75, 950, 1984. 

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