PHILADELPHIA, Aug. 22, 2012 — Camouflage face makeup for warfare is undergoing one of the most fundamental changes in thousands of years, as scientists today described a new face paint that both hides soldiers from the enemy and shields their faces from the searing heat of bomb blasts. Firefighters also could benefit from the new heat-resistant makeup, according to the report.
It was part of a broader symposium on innovations in ingredients for personal care products held during the 244th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society. The meeting, which includes almost 8,600 reports on new discoveries in science and other topics, continues through Thursday. The other reports (abstracts appear below) included new hairsprays, mousses, denture adhesives, tartar-control toothpastes, mouthwashes and personal cleansing products.
Robert Lochhead, Ph.D., who presented the report, explained that soldiers have used face paint for centuries for one kind of protection ― to help their skin blend in with the natural environment and shield them from enemies. The new material continues that tradition, but also provides protection from the searing heat of roadside bomb blasts and other explosions that have claimed a terrible toll in Iraq, Afghanistan and other conflicts.
"The detonation of a roadside bomb or any other powerful explosive produces two dangerous blasts," Lochhead said. "First comes a blast wave of high pressure that spreads out at supersonic speeds and can cause devastating internal injuries. A thermal blast follows almost instantaneously. It is a wave of heat that exceeds 1,112 degrees Fahrenheit. That's as hot as a burning cigarette. The thermal blast lasts only two seconds, but it can literally cook the face, hands and other exposed skin."
In an effort to protect soldiers from this threat, the U.S. Department of Defense has been seeking a solution that Lochhead initially regarded as an impossibility: A material that soldiers could smear on their faces like suntan lotion, leaving a coating that although thinner than a sheet of paper, could protect against that intense heat. Dr. Paige Buchanan, Kelli Booth, Michelle McClusky, Laura Anderson and Lochhead were the team that tackled the challenge. Not only did they succeed, but they discovered a formulation that protects in laboratory experiments way beyond the 2-second heat-wave threat from improvised explosive devices and other bombs.
The new camouflage makeup protects the face and hands for up to 15 seconds before its own temperature rises to the point where a first-degree burn, which is a mild burn, might occur. In some tests, the new face paint can protect for up to 60 seconds, which could be important in giving soldiers time to move away from blast-related fires and also for use by civilian firefighters.
The makeup had to meet several key criteria: It had to reflect intense heat; have camouflage colors suitable for day and night use; be easy to apply and remove; be waterproof; and be non-irritating to the eyes, nose and mouth.
The trickiest part was that the University of Southern Mississippi team had to avoid the use of mineral oil, mineral spirits, fatty substances and other traditional hydrocarbon makeup ingredients. Hydrocarbons can burn in contact with intense heat in the flame spectrum. The team turned to silicones, which are not as flammable because they absorb radiation at wavelengths outside of the intense heat spectrum. Silicones have been replacing hydrocarbons in many commercial cosmetic makeup products as cosmetics companies improve products to confer better feel properties and transfer-resistance.
Another challenge was adding DEET, an insect repellent. The military mandates that all camouflage makeups contain 35 percent DEET. "DEET also is flammable, so when the Department of Defense asked us to incorporate it, we didn't think we could do it," Lochhead noted. But the team successfully included DEET by encapsulating it in a hydrogel substance, a water-rich material that prevented DEET from catching fire.
It already has passed the preliminary laboratory tests needed to determine whether development should continue. Lochhead's team also plans tests of the material on other surfaces to try to protect clothing, tents and other items from burning, and a colorless version is being developed for firefighters.
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Abstracts from the symposium "Polymers for Personal Care and Cosmetics" follow.
Abstracts
Makeup designed to protect skin from ballistic heat
Robert Y. Lochhead1 , The University of Southern Mississippi, The School of Polymers and High Performance Materials, 118 College Drive, #5050, Hattiesburg, MS, 39406-0001, United States , 601-266-5945, robert.lochhead@usm.edu
Warfighters and firefighters can be exposed to intense thermal fluxes that can cause severe burns on exposed skin. Burn injuries are exacerbated by oil or wax-based face paint that can melt on the face and ignite and transfer heat to the tissue. There is a need to ameliorate damage to the skin for such intense heat fluxes. We used high throughput formulation techniques to construct formulations designed to reflect heat from the skin. We avoided ingredients containing C-C and/or C-H bonds that absorb in the flame region of the spectrum. Fortunately, the Si-O-Si bond in silicones absorbs at wavelengths around 9 microns, which is just outside the intense flame spectrum. Makeup formulations for protection against ballistic heat were formulated using select polymeric film formers and hydrogels to shield volatile flammable component ingredients such as DEET.
(Research conducted under Contract No. W911QY-09-C-0037 awarded by the United States Department of Defense (Army).
In vitro characterization of cosmetic and viscoelastic effects of firming polymers
Chung-yi Chiang1 , Unilever, 40 Merritt Boulevard, Trumbull, CT, 06611, United States , 203-381-5741, chung-yi.chiang@unilever.com
Polymers are ingredients commonly used in cosmetic and personal care products to primarily tune the rheology and/or sensory properties of products. The formation of leave-on polymer film on the skin surface would affect consumer's visual and tactile perceptions. The viscoelastic properties of polymer films on skin are believed to drive consumer's immediate perceptions of attributes such as firming. Therefore, tuning proper viscoelastic properties for the polymeric film on skin is a key factor in cosmetic formulation design. A creep measurement on synthetic substrate mimicking skin viscoelasticity and a standard linear solid model were developed to characterize the mechanical properties of products in experiments simulating the application process. A commercialized firming polymer was used to demonstrate the mechanical effects of polymer doses in products. In addition, a variety of polymers with different chemical structures were tested to help with the selection of polymers for optimizing the skin-care products and achieving the targeted concepts.
Beyond thickening: Use of alkyl acrylate crosspolymer in personal care formulations
Daphne Benderly1 , Presperse Corporation, 635 Pierce Street, Somerset, NJ, 08873, United States , 732-356-5200, dbenderly@presperse.com
Polymeric thickeners have been used for decades in personal care applications. A newer class of crosslinked copolymer thickener is INCI name Acrylates/C10-30 Alkyl Acrylate Crosspolymer, which has found use in gel, surfactant and emulsion systems. One disadvantage of this polymer type is loss of viscosity upon addition of electrolytes (salts).
Electrolyte resistance can be altered by varying the structure of the crosslinked copolymer - crosslink density and extent of hydrophobic modification. Performance in model systems such as gels and surfactants will be demonstrated, and the thickening mechanism described. For some thickener structures, an added benefit, in addition to building viscosity and electrolyte tolerance, is the development of a distinctive texture. This texture can be used to differentiate consumer products.
An unexpected thickening synergy between one thickener structure and a surfactant-like preservative is reported.
Modern polyurethane polymers: Structure-property relationships
Yuliya Berezkin1 , Bayer MaterialScience, LLC, Coatings, Adhesives and Sealants/ Spetialties/ Personal Care, 100 Bayer Road, Pittsburgh, PA, 15205, United States , 412-777-4176, yuliya.berezkin@bayer.com
The intrinsic features of polyurethane polymers - such as elasticity, clarity, and tunable mechanical properties - are found to be key in industrial and personal care applications. Understanding structure-property relationships of polyurethanes is necessary when designing smart multifunctional materials for specific end-uses.
Polyurethanes have a segmented structure of block copolymers where soft and hard segments form micro domains that may result in two-phase morphology. For example, a change in the molecular weight of the soft segment may affect phase separation that, in turn, dictates a very unique thermodynamic behaviour of the polymer altering its mechanical characteristics. The nature of the building blocks and polymer morphology greatly affect film forming properties, stiffness, and polymer behaviour under thermal and physical conditions.
This paper will review effects of polymer structure on biodegradability and chemical resistance. Physical-chemical characteristics of the polymer to achieve shape memory or self-healing effects will also be discussed.
Synthesis, characterization, and in vitro release profiles of biodegradable hydroxycinnamate-based poly(anhydride-esters)
Michelle A. Ouimet1 , Rutgers, The State University of New Jersey, Department of Chemistry and Chemical Biology, 610 Taylor Road, Piscataway, New Jersey, 08854, United States , 732-445-5630, mouimet@rci.rutgers.edu
A novel series of hydroxycinnamate-based biodegradable polymers was prepared by chemically incorporating antimicrobial/antioxidant bioactives (e.g., p-coumaric, ferulic, and sinapic acids) into poly(anhydride-esters) of differing hydrophilicity. A Knoevenagel condensation synthetic approach for preparing polymer precursors and solution polymerization methods utilized to yield biodegradable polymers. Preliminary studies of the polymer in vitro release profiles demonstrated that the hydroxycinnamate-based polymers are hydrolytically degradable and release the chemically incorporated bioactives over a prolonged period of time (> 1 month). Controlled release of such naturally derived bioactives would be advantageous for many cosmetic, skin care, and personal care formulations.
Wettability of silicones
Michael J. Owen1 , Michigan Molecular Institute, 1910 West St. Andrews Road, Midland, Michigan, 48640, United States , 989-631-7339, michaelowen01@chartermi.net
The low surface energy and hydrophobicity of polydimethylsiloxane (PDMS) has led to its widespread use in personal care and cosmetic products. However, some applications require oleophobicity as well as hydrophobicity and for this reason, fluorosilicones are of interest in this field. Perceived benefits of incorporation of silicones into these products can be difficult to quantify but one quantitative index of wettability is the contact angle a given liquid exhibits on a silicone substrate. The most commonly studied liquids are water and alkanes, particularly n-hexadecane, useful indicators of hydrophobicity and oleophobicity, respectively. Such data are available for PDMS and a variety of fluorosilicones including polymethyltrifluoropropylsiloxane (PMTFPS). These data are reviewed and compared with other fluorocarbon materials, particularly n-perfluoroeicosane (C20F42). The fundamental reasons for the trends in these data are explored in the light of fundamental attributes of these materials such as low intermolecular forces and polymer backbone architecture and flexibility.
Acetylene based polymers in personal care applications
Osama M. Musa1 , Ashland Specialty Ingredients, Corporate Research Center, 1361 Alps Road, Wayne, NJ, 07470, United States , 973-628-3265, omusa@ashland.com
We will discuss acetylenic-based polymers for personal care derived from vinyl pyrrolidone, vinyl caprolactam and methyl vinyl ether monomers. These vinyl lactam-based polymers have been made via solution, precipitation and dispersion polymerization techniques. By varying ratios of vinyl lactam with other functional monomers, random copolymers with the desired benefits/properties can be achieved. Their polymer architectures can range among linear, branched and crosslinked, and they can be water-soluble or water-swellable. Their polymer functionality can be non-ionic, cationic or anionic in nature. Physical characteristics of the representative lactam-based polymers based on their functionality will be presented along with their applications in personal care industry. Some known applications include hairsprays, hair styling gels, hair conditioning, teeth whiting, and waterproofing sun-creams. Finally, chemistry of methyl vinyl ether (and isobutylene)-maleic anhydride alternating copolymers will be presented, which allow post-polymerization modifications, resulting in broad range tailor-made materials having unique characteristics. Representative known applications of MVE (or IB)-based polymers are hairsprays, mousses, denture adhesives, tartar-control toothpastes and tablet coatings.
Controlled synthesis of multifunctional polymers with "conflicting properties" by RAFT for personal care applications
Matthias Haeussler1 , CSIRO, CMSE, Bayview Avenue, Clayton, Vic, 3168, Australia , +61-3-9545-2390, matthias.haeussler@csiro.au
The versatility of the RAFT (Reversible Addition-Fragmentation chain Transfer) technology provides enormous potential for the design and development of multi-functional polymers that are optimised for performance in a range of application areas that includes: surfactants, coatings, dispersants, nanomaterials, therapeutic or active delivery and personal care. This presentation will demonstrate the attributes of the RAFT process as a ground breaking technology offering unprecedented control over the composition, functionality and architecture of polymers obtained through radical polymerization. Examples of block copolymer structures with distinctive physical and chemical properties will be presented and the performance attributes of these polymers will be highlighted.
Ion permeable microcapsules: An approach for remineralization
Stephen M. Gross1 , Creighton University, Department of Chemistry, 2500 California Plaza, Omaha, NE, 68178, United States , 402-280-2270, stephengross@creighton.edu
The prevention of caries continues to remain a prominent concern among dental professionals. Although products such as toothpaste, mouthwash, and sealants have all targeted this process, the challenge against primary and secondary caries still persists. This study provided a distinctive approach through the creation of a ubiquitous platform capable of being incorporated into several types of dentrifices. Solvated calcium, fluoride, and phosphate salts were encapsulated in ion permeable microcapsules and loaded into rosin and resin based varnish formulations. The role of initial salt concentration in the microcapsule, w/w% loading, microcapsule chemical structure, ion type and continuous phase on the ion release rate was studied. It was concluded that varnish formulated with microcapsules released calcium, phosphate and fluoride ions in a biologically available form with a controlled rate of release.
Stars and blocks: Tailoring polymeric rheology modifiers for aqueous media by controlled free radical polymerization
Andre Laschewsky1 , Fraunhofer Institute for Applied Polymer Research, Department of Chemistry, Geiselbergstrasse 69, Potsdam-Golm, 14476, Germany , 493315681327, 493315683000, andre.laschewsky@iap.fraunhofer.de
Associative telechelics are particularly versatile and effective for thickening or gelling aqueous formulations. As alternative to the dominating hydrophobically end-capped poly(ethylene glycol) derivatives, we have explored the use of controlled free radical polymerization for synthesizing associative telechelic water-soluble polymers directly, without the need of post-polymerization modification steps. Varying the hydrophobicity and the number of the hydrophobic end-groups, as well as the nature and the chain length of the hydrophilic polymer, we present the associative properties of various star, block and star-block copolymers made from acrylic monomers. Moreover, we demonstrate how to extend the strategy to thermo-responsive systems.
Recent advances in self-healing polymers and coatings
Jamil Baghdachi1 , Eastern Michigan University, School of Engineering Technology, 118 Sill Hall, Ypsilanti, MI, 48167, United States , 734-487-3192, jbaghdach@emich.edu
In an effort to mimic self-healing functions in biological systems, we report here the development of polymeric coating systems that are stimuli responsive and possess the ability to self-heal when damaged. This work describes coatings that contain small amounts of healing agent in the form of microcapsule homogeneously dispersed in the coating medium. The most attractive feature of this system is that the factors that cause the most damage to the coating, such as humidity, mechanical compromise, exposure to high temperatures etc., are the same factors that initiate self-healing phenomenon. This property is unique since the extent of the healing is proportional to the magnitude of the damage, i.e., repair on demand. It was confirmed that the simulated natural aging or mechanical damage triggered the release of healing agents, repaired the damage, restored the integrity of the coating and enhanced overall coating properties. The development of self-healing materials has the potential to significantly impact the coatings and related industries by enhancing coatings' performance and service life.
Novel cationic latex as an opacifier for cleansing formulations
Fanwen Zeng1 , The Dow Chemical Company, Dow Advanced Materials, 727 Norristown Road, Spring House, PA, 19477, United States , 215-619-5754, fzeng@dow.com
Opacifier technology has been applied in cleansing formulations to provide an opaque and creamy appearance in consumer products. Styrene/acrylate latex (SAL) is one of the most widely used technologies. Conventionally, this opacifier technology is based on latexes stabilized with anionic groups on the surfaces. It is being used in anionic surfactant-based systems at slightly acidic to neutral pH. However, this technology is not compatible in cleansing formulations that contain a higher content of cationic polymers. In this paper, we describe a novel cationic SAL that is prepared by an emulsion polymerization process. The compatibility and long term formulation stability is markedly improved with this cationic SAL vs. the anionic counterpart when it is used in a cleansing formulation containing higher content of a variety of cationic polymer ingredients.
Styrene/acrylates copolymer as film former for improved hair surface luster
Miao Wang1 , Dow Chemical Company, 727 Norristown Road, Spring House, PA, United States , 215-619-1439, miaowang@dow.com
Shine is one of the most sought-after and most desirable criteria for a hair care product, including hair styling. Hair fixative polymers can provide hold performance, however they have been relying on silicone to provide shine, which has limited shine benefit, diminished hold performance, and are not long lasting. The study was to understand the impact of polymer physical properties, and formulation parameters on shine and hold performance in hair styling products.
Bifunctional synthetic fluid: Polyalphaolefin (PAO)-diphenylamine
Abhimanyu O. Patil1 , ExxonMobil Research and Engineering Company, Corporate Strategic Research, 1545 Route 22 East, Annandale, NJ, 08801, United States , 908-730-2639, abhimanyu.o.patil@exxonmobil.com
1-Decene dimer with terminal double bond was reacted with diphenylamine using acidic catalyst to obtain antioxidant bound fluid. The use of the two different alkylation catalysts were explored: Solid acid clay and 1-ethyl-3-methyl imidazolium heptachloroaluminate [emim+][Al2Cl7-]. The talk will focus on the synthetic aspect of the work with emphasis on the intricacies of the alkylation and oligomerization chemistries revealed by mass spectroscopy.
Next generation mildness for personal care: Nonpenetrating polymerized surfactants for cleansing applications
Michael J. Fevola1 , Johnson & Johnson Consumer and Personal Products Worldwide, Division of Johnson & Johnson Consumer Companies, Inc., 199 Grandview Road, Skillman, NJ, 08558, United States , 908-874-2418, mfevola@its.jnj.com
Most personal cleansing products rely on conventional small-molecule surfactants to deliver the cleansing and foaming performance expected by consumers. Despite all of their beneficial functions, these surfactants can exhibit significant irritation potential. The micelle penetration theory of surfactant induced irritation has inspired new methods of improving mildness which are based on the control and prevention of micelle penetration. Building on this theory, we have demonstrated that the irritation potential of surfactant micelles is inversely proportional to the hydrodynamic size of the micelles; thus, surfactant blends exhibiting larger micelle sizes tend to be milder compared to surfactant blends with smaller micelle sizes. However, because micelle size distributions tend to be broad in nature, even mild surfactant blends contain a significant fraction of small micelles that are able to penetrate into tissue. Polymerized surfactants (PSs) comprised of amphiphilic repeat units overcome the problem of surfactant penetration by enabling the formation of micelles that are too large to penetrate into tissue. The physical properties of PSs can be manipulated via chemical design to provide materials that function like conventional surfactants (e.g. PSs exhibit foaming, wetting, and solubilization behaviors) with the benefits of zero tissue penetration and tremendous reduction in irritation potential.