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Gloves
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
Marie-Noëlle Crépy, Pierre Hoerner
Fluorocarbon elastomers (FKM) are advanced materials obtained by copolymerization of various fluoro-monomers such as vinylidene fluoride and hexafluoropropylene. This elastomer family was discovered by DuPont in 1958 and is sold under the trade name Viton™. Nowadays, a few other suppliers offer similar products under different brands. The main interest of FKM is their unique resistance against a wide variety of chemicals, especially most chlorinated and aromatic solvents, and with extreme heat and oil resistance. However, these products remain significantly more expensive compared to any other elastomers.
Patterns of Injury
Published in Mansoor Khan, David Nott, Fundamentals of Frontline Surgery, 2021
Danyal Magnus, Katherine A. Brown, Mansoor Khan, William G. Proud
Explosives are a particular example of a range of substances called ‘energetic materials’ (EMs). The term describes a variety of materials that can be divided into three broad categories: explosives, propellants, and pyrotechnics. Explosives are defined as materials which react to produce a violent expansion of hot gas – an explosion which rapidly delivers energy to its surroundings. The rate of transformation from solid to hot gas takes place in microseconds. Propellants are less violent in reaction and, as the name implies, are used to accelerate objects such as missiles and bullets. The time taken to go from solid to gas is in milliseconds. Some materials such as gunpowder can be used either as an explosive charge or as a propellant. The difference in behaviour is dependent on the amount of containment/confinement around the gunpowder – the more confined, the more violent the reaction. The last class is pyrotechnics, which are a myriad of chemical mixtures which react to produce intense heat, smoke, light, or noise with reaction times from milliseconds to several minutes. While the effect of a white-light flare can be easily appreciated, the blinding light and accompanying heat in pyrotechnics can present significant, hidden hazards. Magnesium Teflon, Viton (MTV) is a classic composition used in infrared-emitting flares, the flame is invisible to the naked eye, but the megawatt of energy released can cause deep, thorough skin burns. Several components of pyrotechnics can be toxic (or can release toxic materials), which can add a longer-term toxic effect on top of any acute effect.
Prevention of Microbial Contamination during Manufacturing
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Gaskets are used to establish mechanical seal which fills the space in piping connections. Gasket sanitary design considerations require construction with materials of inert chemical composition compatible with cleaners, sanitizers and product formulations that do not react with or absorb product preservatives. It is well known that plasticizers can leach from certain types of PVC and inactivate phenolic preservatives, while low to medium density polyethylene can be permeable to oil-soluble preservatives such as parabens. Polyurethane can reduce the antimicrobial activity of phenolic and quaternary ammonium preservatives (63). Benzyl alcohol is known to interact with polyethylene and polystyrene (64). Benzalkonium chloride and benzethonium chloride can be absorbed by polyethylene, polypropylene, polystyrene and PVC (65). Parabens can be absorbed into rubber. In addition, parabens and phenols can be absorbed into nylon and plasticized PVC (66). Teflon™ (polytetrafluoroethylene) and Viton™ (synthetic rubber and fluoropolymer elastomer) are acceptable materials for gasket composition (62). Gaskets should be non-porous in order to prevent the entry of microorganisms into pores and holes. When using gaskets, it is important to establish a proper seal during the installation to prevent the accumulation of bulk finished product in the connection.
An extraction free modified o-phthalaldehyde assay for quantifying residual protein and microbial biofilms on surfaces
Published in Biofouling, 2018
Allan Guan, Yi Wang, K. Scott Phillips
OPA (MP Biomedicals, Santa Ana, CA, USA), N-acetyl-L-cysteine (NAC), tryptic soy broth (TSB, Millipore Sigma, Burlington, MA, USA), and 24-well, clear plates were purchased from Fisher Scientific (Waltham, MA, USA). Bovine serum albumin (BSA) was purchased from Sigma-Aldrich (St Louis, MO, USA). Phosphate buffered saline (PBS) (137 mM NaCl, 2.7 mM potassium chloride, 10 mM phosphate) was prepared from 10× stock solution purchased from VWR (Philadelphia, PA, USA). Stainless steel (SS) (304 2B, smooth mill finish) coupons (1 cm × 1 cm × 1 mm) were purchased from Atlantic Stainless (North Attleborough, MA, USA). Staphylococcus epidermidis (ATCC® 35984™) was purchased from ATCC (Manassas, VA, USA). Viton tubing (smooth and non-textured) was purchased from Endoscopy Replacement Parts (Wellesley, MA, USA).
Comparative analysis of two isocyanate-free urethane-based gels for antifouling applications
Published in Biofouling, 2021
Vishal Vignesh, Shane Stafslien, Morgan Evans, Kellen Wise, Alec Marmo, Michael Tonks, Anthony Brennan
AAM, HEMA and Irgacure 651 (2,2-dimethoxyacetophenone) were obtained from Sigma Aldrich. HFBMA was obtained from Alfa Aeser. Non-isocyanate urethane crosslinkers NIUDMA (E9/E11/E12) were synthesized by the Brennan Research Group as detailed in the work by Vignesh et al. (2021). Ethanol, nitrogen gas (N2, ultra-high purity), deionized water, heat plate equipped with magnetic stirrer, disposable pipettes, glass slides (Fisher), glass plates, clamps, Fluoroelastomer (Viton®) gasket mold were all obtained from the Brennan Research Group. All other chemicals, unless explicitly mentioned, were utilized as received. Intersleek® 700, 900 and 1100 SR commercial FR coating systems were received from AkzoNobel and prepared as specified by the manufacturer.