Research on Isododecane: Protection and Application

Introduction

2,2,4,6,6-Pentamethylheptane is commonly named Isododecane. Isododecane is a colorless, odorless liquid with low volatility.(Figure 1) Due to its low volatility and good stability, isododecane is often used as solvent, carrier oil, ingredient stabilizer and other applications, especially in cosmetics, skin care products, skin care products, coatings, sprays and other fields. Its lower volatility makes the product less volatile during use, helping to maintain its stability and long-term effectiveness.

1.Isododecane is the main emitted pollutant when painters use the odorless thinner

A solid-phase microextraction (SPME) sampling device, called a needle trap samplers (NTS) that were packed with 60–80 mesh divinylbenzene (DVB) particles, was used to extract indoor volatile organic compounds (VOCs) that were emitted in an oil painting studio. This work compared the sampling performances of a passive NTS and an active charcoal desorption tube that was connected toa personal sampling pump (Method 1501), developed by the National Institute of Occupational Safety and Health, USA. The experimental results reveal that the NTS is a dependable alternative device to Method 1501 for monitoring indoor air quality. 2,2,4,6,6-Pentamethylheptane (isododecane) is the main emitted pollutant when oil painters use odorless thinner as a substitute solvent for turpentine oil, and the mean exposed concentrations of isododecane determined by NTS ranged from 0.83 to 3.10 ppm, which were dependent on whether the indoor ventilation was performed by the natural or mechanic mode. To maintain adequate air exchange rates in an oil painting studio,doors should be opened to increase air circulation, lowering the concentrations of isododecane to which painters are exposed.Implications: A needle trap sampler (NTS) was used to sample VOCs from oil painting in an indoor studio. Isododecane is the main emitted pollutant when painters use the odorless thinner.The NTS was evaluated to be a dependable alternative to Method 1501 for monitoring indoor air quality. To maintain adequate air exchange rates in a painting studio, doors should be opened to lower concentrations of VOCs.[1]

2.Advantages of Isododecane in the Production of Isoprene

Although isododecane is expensive and is not a realistic solvent for a prospective industrial process, authors chose it to study the effect of branching on selectivity. Both linear and branched systems have exhibited similar selectivity, showing the reaction profile is independent of solvent branching.Among the solvents tested, the use of simple long chain alkanes such as octane but also highly branched alkanes such as isododecane resulted in high conversion and selectivity to isoprene.

In this work the researchers demonstrate the selective catalytic conversion of prenol, which is an allylic alcohol that can be prepared from renewable resources to isoprene. The catalyst is aninexpensive molybdenum complex (Molyvan L) designed and used as an additive for lubricants. Isoprene is generated under relatively mild reaction parameters at 130–150°C,for 2 h, under vapor pressure conditions that do not exceed 50 psi. Two cases were studied: one in which Molyvan L was dissolved in a base oil at 1% concentration (weight/weight) and then mixed with a solvent and prenol and the other in which neat Molyvan L was introduced in the reaction and the base oil was replaced with the solvent and prenol.We investigated the selectivity of the reaction using the following solvents in both cases:dodecane, dodecanol, isododecane, octane, blendstock for oxygenate blending (BOB3),a fuel surrogate, a polyalphaolefin (PAO4), and methoxy polyethylene glycol (methoxyPEG350). Although conversion of prenol was above 94% in all experiments, isoprene was formed with various degrees of efficiency alongside a prenol isomeric alcohol, diprenylether and mixed ether via intramolecular and intermolecular dehydration reactions.Dodecane appeared to have the highest level of selectivity initially in base oil so they studied the effect of various dodecane-like solvents on isoprene yield and product profile.Surprisingly, octane (similar to dodecane) and isododecane (branched alkane) generated insignificant amounts of byproducts, essentially providing the highly desired isoprene with a very high selectivity. Branching of the solvent does not appear to have an effect on selectivity. Another advantage of this catalyst is the low loadings required to effect the transformation; that is, 0.25% (weight/volume) in the cases using neat Molyvan L and 0.5%(weight/volume) in the cases using Molyvan L dissolved in the base oil. Provided that prenolcan be produced in large scale from bioresources, this work would enable the sustainable production of isoprene, in good yield, and with very high selectivity.[2]

3.Research on the Application of Isododecane in Sunscreens

Isododecane functions as a solvent and also functions as an emollient for an oil-soluble UV absorber. Isododecane is transparent at 355 nm. Whileα-tocopherol is oil-soluble, Trolox is practically insoluble incosmetic oils. Menthyl anthranilate (MA, tradename meradimate) is a UV-A absorber. The interactions of ground-state molecular oxygen with the long-lived triplet state of MA produce singlet oxygen through energy transfer.The quantum yield of singlet oxygen generation is 0.12 in air-saturated ethanol. Kinetic traces of the near IR phosphorescence of singlet oxygen generated by MA-photosensitization have been measured in the absence and presence of Trolox (a water-soluble analogue of vitamin E and a quencher of singlet oxygen)and α-tocopherol (vitamin E, a natural antioxidant) in ethanol. Fluorescence and transient absorption measurements suggest that Trolox and α-tocopherol quench the lowest excited singlet and triplet statesof MA. As a result, Trolox and α-tocopherol suppress MA-photosensitized singlet oxygen generation. Not only the quenching of singlet oxygen but also the suppression of singlet oxygen generation is the mechanism of antioxidant properties of Trolox and α-tocopherol for MA. The ability of α-tocopherol to suppress the MA-photosensitized singlet oxygen generation in isododecane, used as a solvent for an oil-soluble UV absorber, is close to that in ethanol. Suppression of sunscreen-photosensitized singlet oxygen generation is an important method for the formulation of safe cosmetic sunscreens.[3]

References

[1]Cheng WH, Huang HL, Chuang MH. Use of passive SPME sampling devices to determine exposure of oil painters to organic compounds. J Air Waste Manag Assoc. 2020;70(3):253-259. doi:10.1080/10962247.2019.1694090

[2]Kothandaraman J, Cosimbescu L, Swita MS. Solvent-Induced Selectivity of Isoprene From Bio-Derived Prenol. Front Chem. 2022;10:879129. Published 2022 May 17. doi:10.3389/fchem.2022.879129

[3]Kitasaka S, Yagi M, Kikuchi A. Suppression of menthyl anthranilate (UV-A sunscreen)-sensitized singlet oxygen generation by Trolox and α-tocopherol. Photochem Photobiol Sci. 2020;19(7):913-919. doi:10.1039/d0pp00023j