DIMETHICONE

Dimethicone is used in the manufacture of makeup products, body lotions, moisturizers in the cosmetics industry, and hair conditioners.
Dimethicone is also used in personal care products because of its softening properties.
Dimethicone is used in the manufacture of shampoos, conditioners, and hair care products.

CAS Numbers: Dimethicone is a polymeric substance, so several CAS numbers exist depending on grade:
CAS Number (commonly used): 9006-65-9
Other CAS Numbers: 63148-62-9, 9016-00-6, 141-62-8
EC Numbers:
EC Number: 205-491-7
EC Number (alternative listing): 205-492-2
Chemical Formula: (C₂H₆OSi)ₙ or –[Si(CH₃)₂–O]ₙ–
Molecular Structure: Linear polymer composed of repeating dimethylsiloxane units

SYNONYMS:
Polydimethylsiloxane, Dimethylpolysiloxane, Dimethyl Silicone, Silicone Fluid, Silicone Oil, Dimeticone, PDMS, Methyl Polysiloxane, Polymethylsiloxane, Poly[Oxy(Dimethylsilylene)], Siloxanes and Silicones Di-Me, Dimethylsilicone Oil, Silicone Fluid DC-200, Reduced Volatility Polydimethylsiloxane, Simethicone (mixture form), Silicone Antifoam, Polydimethylsiloxane Fluid, poly(dimethylsiloxane), PDMS, dimethicone, dimethylpolysiloxane, E900, Dimethicone, Dimethicone, Polydimethylsiloxane, Polydimethylsiloxane, Dimethyl Silicon, Methyl Silicon, Silicone Oil, Emulsified Silicone Oil, Polymer, Silicon, Emulsifier, 9006-65-9, PDMS, Elastomer, Organic Silicone Oil, DM 350, DM 1000, DM 5000

Dimethicone, or polydimethylsiloxane (PDMS), is a versatile silicone-based polymer commonly used in cosmetics, skincare, and medical applications as a lubricant, softener, and protectant.
Dimethicone creates a smooth, velvety texture, prevents moisture loss in skin, and treats minor irritations.

Dimethicone is known by two names: Dimethicone and Polydimethylsiloxane.
Dimethicone is referred to as silicone oil.
Dimethicone is a silicone-based polymer.

Dimethicone is a chemical with viscoelastic properties.
For this reason, Dimethicone has been observed to have moisturizing effects on human skin.
Dimethicones are among the most commonly used elastomers.

Dimethicones are the simplest member of the silicone family.
Dimethicone (also called polymethylsiloxane) is a silicon-based polymer used as a lubricant and conditioning agent.
Well, Dimethicone’s a type of silicone, which you can find in a lot of beauty products.

Dimethicone’s what gives your primer that velvety feel and helps your foundation glide like a dream.
Dimethicone is a non-soluble silicone, meaning it doesn’t dissolve in water and tends to stick around until you wash it off.
Silicones, in general, are a broad family of synthetic compounds derived from silica (a naturally occurring mineral).

In the ingredient lists, you’ll recognize them by names that end in “-cone,” “-conol,” “-silane,” or “-siloxane.”
These ingredients are super handy in cosmetics because they give products a silky smooth texture and help lock in moisture.
Dimethicone does this well—it forms a barrier on your skin, keeping hydration in without being greasy.

Dimethicone is a silicone-based polymer that is frequently used as a skin protectant in skincare products.
The second most common moisturizing ingredient found in moisturizers after petrolatum, dimethicone helps condition the skin—improving its softness and flexibility.

Dimethicone is a type of silicone (technically known as a non-volatile/linear silicone).
Dimethicone is one of the most frequently used emollient (softening) ingredients in moisturisers, well known for its gentleness and effectiveness.

Dimethicone is recognised as a “skin protectant” by the U.S. FDA, when used in over-the-counter products in concentrations of 1-30%.
Dimethicone forms an air-permeable barrier that works to prevent moisture loss, so skin better retains hydration, while still allowing natural perspiration to evaporate.

Dimethicone imparts a wonderfully silky (but not greasy) feel, which makes it especially popular in oil-free moisturisers.
Dimethicone is considered a synthetic ingredient, even though it’s derived from natural silicon.
Dimethicone has a long track record of being recognised as safe in cosmetic products.

Dimethicone is a silicone-based ingredient used in many personal care products.
Dimethicone keeps all of the ingredients in a product from separating.
Dimethicone also gives these products a smooth, silky texture.

When applied to the skin or hair, dimethicone creates a physical barrier to seal in hydration, keeping skin moisturized and hair frizz-free.
In cosmetics, dimethicone helps to fill in fine lines and wrinkles.
Dimethicone helps your makeup look even rather than cakey, and gives it a matte finish.

Dimethicone is also noncomedogenic, meaning it won’t clog pores.
Dimethicone is a silicone polymer with a wide variety of uses, from cosmetics to industrial lubrication and passive daytime radiative cooling.
Dimethicone is particularly known for its unusual rheological (or flow) properties.

Dimethicone is optically clear and, in general, inert, non-toxic, and non-flammable.
Dimethicone is one of several types of silicone oil (polymerized siloxane).
The applications of Dimethicone range from contact lenses and medical devices to elastomers; it is also present in shampoos (as it makes hair shiny and slippery), food (antifoaming agent), caulk, lubricants and heat-resistant tiles.

Dimethicone is a silicone oil that is also known as polydimethylsiloxane.
Dimethicone has viscoelastic properties.
Dimethicone is a man-made silicone molecule commonly found in beauty products thanks to its emollient properties.

According to the Cosmetic Ingredient Review (CIR), Dimethicone functions as an anti-foaming agent, skin protectant, skin conditioning agent, and hair conditioning agent.
Dimethicone’s non-comedogenic and hypoallergenic, making it suitable for most skin types, including sensitive and acne-prone skin.

While you can find dimethicone in a wide range of products, it’s most commonly found in products designed to help hydrate or lock in moisture, including facial serums, moisturizers, hair conditioners, and leave-in hair products.
Dimethicone’s also frequently found in liquid makeup products such as primers, foundations, and concealers.

Dimethicone is a silicon-based polymer, more commonly known as silicones.
Its name indicates that Dimethicone is a silicone based molecule with two methyl groups.
(Di=2, methi=methyl, cone=silicon).

When you look at Dimethicone's structure above, you can see that an oxygen binds two silicon based molecules into one molecule.
Dimethicone has a smooth texture and historically was common in moisturizers and other creamy feeling products.

Recently, Dimethicone is becoming less popular because of its environmental impact and an influx of great alternatives.
If you are interested in moisturizers without dimethicone, you can see our full collection here!
Before we get into why dimethicone is falling out of favor, it is important to understand why it was used in the first place.

USES and APPLICATIONS of DIMETHICONE:
Dimethicone's most common application is in the cosmetics industry.
In this field, Dimethicone possesses excellent hydrophobic moisture resistance and good light permeability.
Due to its oil-like properties, Dimethicone is widely used in the manufacture of skincare products because it fills in fine lines and irregular skin textures.

Dimethicone is used in the manufacture of makeup products, body lotions, moisturizers in the cosmetics industry, and hair conditioners.
Dimethicone is also used in personal care products because of its softening properties.

Dimethicone (Polydimethylsiloxane), a natural silicone derivative, prevents moisture loss from the skin by creating a permeable barrier, giving the skin a smooth feel.
Dimethicone is used in the manufacture of products that soothe skin irritations caused by diapers on babies' skin.

Here, Dimethicone increases moisture while reducing itching and irritation.
Dimethicone is used in the manufacture of shampoos, conditioners, and hair care products.
Surfactants can be used as anti-foaming chemicals.

Dimethicone (Polydimethylsiloxane) is used in the manufacture of root canal sealants.
Silicone oils are increasingly used in the manufacture of some pesticides that are less harmful to the environment.
Dimethicone is used in the production of silicone emulsions, which are used in silicone masterbatch manufacturing.

These silicone oils can be high molecular weight or low molecular weight.
This generally varies depending on the application and properties of the silicone masterbatch.
In pharmaceutical products, titanium dioxide, corn starch, bovine gelatin, and silicone oil are used in the manufacture of some capsules along with the active ingredient.

In the production of roll-on deodorants, Dimethicone is used in the oil phase together with Liquid Paraffin (Paraffin Oil).
Dimethicone is used in the nut industry for foam cutting and oil stabilization.
The use of soft lithography in biomedical microelectromechanical systems is emerging.

Dimethicone is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.
As for skincare, Dimethicone makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive).

Also, works well to fill in fine lines and wrinkles and give skin a plump look.
There are also scar treatment gels out there using dimethicone as their base ingredient.
Dimethicone helps to soften scars and increase their elasticity.

As for hair care, Dimethicone is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing.
Depending on your hair type, Dimethicone can be a bit difficult to wash out and might cause some build-up.

This is not true to all silicones, only the non-volatile types.
Cosmetics & Skincare: Dimethicone is used in moisturizers, foundations, and primers for its ability to smooth skin and create a barrier, acting as the second most common moisturizing ingredient after petrolatum.

Hair Care: Dimethicone is included in shampoos and conditioners to provide shine, hydration, and reduce frizz.
Medical & Health: Dimethicone is used as an anti-foaming agent in medicine, for treating dry/chafed skin, diaper rash, and in lice treatments.
Industrial: Dimethicone is used as a lubricant, hydraulic fluid, and in, sealant applications.

Food Industry: Dimethicone is used as a food-grade antifoaming agent in frying oils and food processing
Dimethicone is being used in the making of synthetic gecko adhesion dry adhesive materials, to date only in laboratory test quantities.
Some flexible electronics researchers use Dimethicone because of its low cost, easy fabrication, flexibility, and optical transparency.

Yet, for fluorescence imaging at different wavelengths, Dimethicone shows least autofluorescence and is comparable to BoroFloat glass.
Condom lubricant: Dimethicone is widely used as a condom lubricant.
Dimethicone can be used as a sorbent for the analysis of headspace (dissolved gas analysis) of food.

Dimethicone is used as a surfactant, antifoaming agent, carminative in various products such as medical devices, food products, and lubricants.
Dimethicone is used in a number of health and beauty products including hair care products such as shampoo, conditioner, leave-in conditioner, and de-tangling products.

On skin, Dimethicone is also observed to have moisturizing actions.
A study found that the 100 % dimethicone product is a safe and highly effective head lice treatment for children and may serve as less toxic and less resistance-prone alternative to pesticide-containing products.

Dimethicone may also be used with other ingredients such as alumina to coat zinc oxide or titanium dioxide in sunscreen formulation to help the actives distribute evenly on skin, providing uniform protection.

-Domestic and niche uses of Dimethicone:
Many people are indirectly familiar with Dimethicone because it is an important component in Silly Putty, to which Dimethicone imparts its characteristic viscoelastic properties.
Another toy Dimethicone is used in is Kinetic Sand.

The rubbery, vinegary-smelling silicone caulks, adhesives, and aquarium sealants are also well-known.
Dimethicone is also used as a component in silicone grease and other silicone based lubricants, as well as in defoaming agents, mold release agents, damping fluids, heat transfer fluids, polishes, cosmetics, hair conditioners, shining latex, and other applications.

-Foods uses of Dimethicone:
Dimethicone is added to many cooking oils (as an anti-foaming agent) to prevent oil splatter during the cooking process.
As a result of this, Dimethicone can be found in trace quantities in many fast food items such as McDonald's Chicken McNuggets, french fries, hash browns, milkshakes and smoothies and Wendy's french fries.
Under European food additive regulations, Dimethicone is listed as E900.
In the US the application of antifoams in food is regulated by 21 CFR §173.340.

-Advanced surfaces use of Dimethicone:
Dimethicone is widely employed in the fabrication of advanced surfaces such as superhydrophobic coatings due to its inherent low surface energy, chemical inertness, and flexibility.
Its ability to replicate micro/nanostructures and support hierarchical texturing makes Dimethicone ideal for creating durable, water-repellent surfaces with enhanced functionality.

-Surfactants and antifoaming agents use of Dimethicone:
Dimethicone derivatives are common surfactants and are a component of defoamers.
Dimethicone, in a modified form, is used as an herbicide penetrant and is a critical ingredient in water-repelling coatings, such as Rain-X.
Hydraulic fluids and related applications: Dimethicone is used in the active silicone fluid in automotive viscous limited slip differentials and couplings.

-Daytime radiative cooling uses of Dimethicone:
Dimethicone is a common surface material used in passive daytime radiative cooling as a broadband emitter that is high in solar reflectivity and heat emissivity.
Many tested surfaces use Dimethicone because of its potential scalability as a low-cost polymer.
As a daytime radiative cooling surface, Dimethicone has also been tested to improve solar cell efficiency.

-Stereo lithography uses of Dimethicone:
In stereo lithography (SLA) 3D printing, light is projected onto photocuring resin to selectively cure it.
Some types of SLA printer are cured from the bottom of the tank of resin and therefore require the growing model to be peeled away from the base in order for each printed layer to be supplied with a fresh film of uncured resin.
A Dimethicone layer at the bottom of the tank assists this process by absorbing oxygen : the presence of oxygen adjacent to the resin prevents it adhering to the Dimethicone, and the optically clear Dimethicone permits the projected image to pass through to the resin undistorted.

-Medicine and cosmetics use of Dimethicone:
Activated dimethicone, a mixture of polydimethylsiloxanes and silicon dioxide (sometimes called simethicone), is often used in over-the-counter drugs as an antifoaming agent and carminative.

Dimethicone also works as a moisturizer that is lighter and more breathable than typical oils.
Silicone breast implants are made out of a Dimethicone elastomer shell, to which fumed amorphous silica is added, encasing Dimethicone gel or saline solution.

-Skin uses of Dimethicone:
Dimethicone is used variously in the cosmetic and consumer product industry as well.
For example, dimethicone is used widely in skin-moisturizing lotions where it is listed as an active ingredient whose purpose is "skin protection."

Some cosmetic formulations use dimethicone and related siloxane polymers in concentrations of use up to 15%.
The Cosmetic Ingredient Review's (CIR) Expert Panel has concluded that dimethicone and related polymers are "safe as used in cosmetic formulations."

-Hair uses of Dimethicone:
Dimethicone compounds such as amodimethicone, are effective conditioners when formulated to consist of small particles and be soluble in water or alcohol/act as surfactants, and are even more conditioning to the hair than common dimethicone and/or dimethicone copolyols.

-Contact lenses use of Dimethicone:
A proposed use of Dimethicone is contact lens cleaning.
Its physical properties of low elastic modulus and hydrophobicity have been used to clean micro and nano pollutants from contact lens surfaces more effectively than multipurpose solution and finger rubbing.

The researchers involved call the technique PoPPR (polymer on polymer pollution removal) and note that it is highly effective at removing nanoplastic that has adhered to lenses.
The use of Dimethicone in the manufacture of contact lenses was patented (later abandoned).

-As anti-parasitic uses of Dimethicone:
Dimethicone is effective for treating lice in humans.
This is thought to be due not to suffocation (or poisoning), but to its blocking water excretion, which causes insects to die from physiological stress either through prolonged immobilisation or disruption of internal organs such as the gut.

Dimethicone is the active ingredient in an anti-flea preparation sprayed on a cat, found to be equally effective to a widely used more toxic pyriproxifen/permethrin spray.
The parasite becomes trapped and immobilised in the substance, inhibiting adult flea emergence for over three weeks.

-Cosmetics and Personal Care uses of Dimethicone:
Dimethicone is widely used as:
Skin conditioning agent
Moisturizing barrier ingredient
Hair conditioner and detangler
Makeup and sunscreen ingredient
Anti-frizz and shine enhancer in hair products

-Pharmaceutical Uses of Dimethicone:
Skin protectant for irritation and diaper rash
Anti-flatulence medication (simethicone formulations)
Lice treatment formulations

-Industrial Applications of Dimethicone:
Antifoaming agent in industrial processing
Lubricant in machinery
Mold release agent
Additive in paints and coatings
Textile processing agent

WHAT IS THE ROLE OF DIMETHICONE IN PHARMACEUTICAL APPLICATIONS?
For dimethicone to be legally considered an active class of drug, there are certain requirements.
In the silicone pharmaceutical industry, Dimethicone must be graded for Neurofibromatosis (NF).
This type of Dimethicone is used as an active OTC product due to its high hydrophobic properties and the partial protection it can offer against some water-immiscible effects.

The properties that make these silicone polymers stand out in the pharmaceutical and cosmetic industries are as follows.
It not only possesses good lubricity properties, but also provides good softening properties due to having a surface tension lower than the critical surface wetting tension.

Low molecular weight Dimethicone cyclic oligomers are used in cream formulations to treat acne and psoriasis.
Low molecular weight linear Dimethicone oligomers function as a volatile carrier and solvent instead of various propellants.
Some polydimethylsiloxanes have a boiling point of 100 °C.

In comparison, their heat of vaporization is lower than that of water.
They have hydrophobic properties.
The fact that they do not cause a burning sensation on the skin when mixed with ethyl alcohol in formulations explains the use of this type of 
Dimethicone as an ingredient in waterless antifungal treatments.
High molecular weight polydimethylsiloxanes are resistant to washing off once they penetrate the body.
This ensures that UV absorbers do not easily wash off the body when they come into contact with seawater.

This helps in the manufacture of swim-resistant sunscreens.
High molecular weight polydimethylsiloxane can be highly hydrophobic.
However, Dimethicone is quite permeable to moisture and gases.

Therefore, it has a corrosive effect in the application area.
This is one of its undesirable properties.
Scientists are working to eliminate these unsuitable aspects of silicones like Dimethicone in the pharmaceutical and cosmetic industries.

WHAT IS DIMETHICONE USED FOR IN SKINCARE?
Dimethicone comes in several different forms, each with slightly different properties and benefits.
Certain types act as emulsifiers, giving products a smooth, uniform texture, while others help stabilize solutions, ensuring your creams, serums, and lotions perform as intended.

Beyond its functional role in formulations, dimethicone also offers direct benefits for the skin.
As explained in a 2023 article published in the Journal of Cutaneous and Aesthetic Surgery, Dimethicone helps trap moisture, which can stave off dryness and give the skin a smooth look and feel.

In leave-on formulas, such as moisturizers and serums, dimethicone also forms a lightweight barrier on the skin, which can help protect the skin from environmental stressors such as cold, dry air or harsh indoor heating.
Dimethicone is a silicone based ingredient that used to be prized for its texture enhancing properties in skin care.

Despite its widespread use and popularity, concerns regarding its potential impact on skin health and the environment have led many companies and consumers to avoid dimethicone in skin care.
Find out why more people are looking for dimethicone-free products every day, and learn the science of dimethicone here!

WHY DIMETHICONE IS USED IN SKIN CARE PRODUCTS
Dimethicone has been used as a texture additive in cosmetic and skin care products for decades.
Though it is not in vogue anymore, these are some of the reasons dimethicone was popular in the past:

*Moisturizers: 
By creating a protective layer on the skin, dimethicone helps prevent moisture loss, keeping your skin hydrated.

*Smooth finish: 
Dimethicone creates a silky texture in skincare formulations, leaving a non-greasy finish.
Dimethicone doesn't have the same oiliness as many other creamy ingredients.

*Protective Qualities: 
Dimethicone acts as a barrier against environmental pollutants, helping to shield the skin from external irritants like dirt or smog.

*Wrinkle Smoothing: 
Dimethicone's ability to fill in fine lines and wrinkles temporarily gives the skin a smoother appearance, a sought-after quality in anti-aging skincare products.
Dimethicone doesn't actually help with the causes of aging.

Dimethicone's kind of like using frosting to fill a crack in a wall; It is a very temporary solution.
Understanding these benefits provides insights into why dimethicone has been a preferred ingredient for years.
However, the evolving landscape of skincare is marked by a heightened focus on ingredient safety and environmental responsibility.
Because of these responsibilities we have to each other and the environment, some people are looking beyond dimethicone.

SOFT LITHOGRAPHY USES OF DIMETHICONE:
Dimethicone is commonly used as a stamp resin in the procedure of soft lithography, making it one of the most common materials used for flow delivery in microfluidics chips.
The process of soft lithography consists of creating an elastic stamp, which enables the transfer of patterns of only a few nanometers in size onto glass, silicon or polymer surfaces.

With this type of technique, it is possible to produce devices that can be used in the areas of optic telecommunications or biomedical research.
The stamp is produced from the normal techniques of photolithography or electron-beam lithography.
The resolution depends on the mask used and can reach 6 nm.

The popularity of Dimethicone in microfluidics area is due to its excellent mechanical properties.
Moreover, compared to other materials, it possesses superior optical properties, allowing for minimal background and autofluorescence during fluorescent imaging.

In biomedical (or biological) microelectromechanical systems (bio-MEMS), soft lithography is used extensively for microfluidics in both organic and inorganic contexts.
Silicon wafers are used to design channels, and Dimethicone is then poured over these wafers and left to harden.
When removed, even the smallest of details is left imprinted in the Dimethicone.

With this particular Dimethicone block, hydrophilic surface modification is conducted using plasma etching techniques.
Plasma treatment disrupts surface silicon-methyl bonds, substituting them with alcohol groups, and a plasma-treated glass slide is usually placed on the activated side of the Dimethicone.

Once activation wears off and bonds begin to reform, silicon-oxygen bonds are formed between the surface atoms of the glass and the surface atoms of the Dimethicone, and the slide becomes permanently sealed to the Dimethicone, thus creating a waterproof channel.
With these devices, researchers can utilize various surface chemistry techniques for different functions creating unique lab-on-a-chip devices for rapid parallel testing.

Dimethicone can be cross-linked into networks and is a commonly used system for studying the elasticity of polymer networks.
Dimethicone can be directly patterned by surface-charge lithography.

HOW IS DIMETHICONE PRODUCED?
Silicone oils are produced by reacting octamethylcyclotetrasiloxane and hexamethyldisiloxane in the presence of concentrated sulfuric acid and a tetramethylammonium hydroxide catalyst.

WHAT ARE THE PHYSICAL AND CHEMICAL PROPERTIES OF DIMETHICONE?
Dimethicone is a transparent, viscous liquid that is tasteless, colorless, odorless, and non-toxic.
Dimethicone's viscosity varies according to its molecular weight.

Therefore, as the molecular weight increases, the viscosity increases.
Dimethicone's kinematic viscosity ranges from 10⁻⁶ to 10⁺⁶.

Dimethicone is highly soluble in benzene.
However, Dimethicone has partial solubleness in toluene, xylene, ethyl ether, butanol, and ethyl alcohol.
Dimethicone is slightly soluble in acetone.

Dimethicone is insoluble in paraffin oil and vegetable oil.
Similarly, Dimethicone is insoluble in water.
Dimethicone has chemical stability.

Dimethicone's density at 25 °C is 0.963 g/cm³.
Dimethicone (Polydimethylsiloxane) has a melting point of -50 °C.
Boiling Point: 200-300 °C (varies)

WHAT ARE THE DIFFERENT TYPES OF DIMETHICONE?
Dimethicone varieties differ according to their viscosity.
These are as follows:

1.5 = Viscosity 1.5 mm2/s (Volatile Silicone)
2 = Viscosity 2 mm2/s (Volatile Silicone)
3 = Viscosity 3 mm2/s (Volatile Silicone)
4 = Viscosity 4 mm2/s (Volatile Silicone)
5 = Viscosity 5 mm/s (Volatile Silicone)
10 = Viscosity 10 mm2/s (Volatile Silicone)
20 = Viscosity 20 mm2/s (Volatile Silicone)
50 = Viscosity 50 mm2/s (Volatile Silicone)
100 = Viscosity 100 mm2/s (Volatile Silicone)
200 = Viscosity 200 mm2/s (Volatile Silicone)
350 = Viscosity 350 mm2/s (Volatile Silicone)
500 = Viscosity 500 mm2/s (Volatile Silicone)
1000 = Viscosity 1000 mm2/s (Volatile Silicone)
12500 = Viscosity 12500 mm2/s (Volatile Silicone)
60000 = Viscosity 60000 mm2/s (Volatile Silicone)

TYPES OF DIMETHICONE:
Dimethicone is classified by its viscosity (thickness), which determines its application.
Types range from low viscosity (volatile silicones used for quick absorption) to high viscosity (thick, oily, used for intense, long-lasting barrier protection).

MANUFACTURING of DIMETHICONE:
Dimethicone is produced through the hydrolysis of Si(CH)Cl, forming silanol groups, which are then capped with trimethylsilyl chloride.
Dimethicone is a silicone-based polymer widely used in cosmetics, pharmaceuticals, industrial products, and food processing.
It consists of repeating dimethylsiloxane units, giving the material a flexible, stable, and hydrophobic structure.

Because of its excellent lubricating, water-repellent, and protective properties, dimethicone is commonly used as a skin protectant, emollient, antifoaming agent, and lubricant.
Dimethicone is known for forming a smooth protective film on surfaces while remaining chemically stable and biologically inert.

CHEMICAL CHARACTERISTICS of DIMETHICONE:
Dimethicone is part of the siloxane polymer family and has several distinctive characteristics:
*Silicone polymer composed of alternating silicon and oxygen atoms
*Hydrophobic and water-repellent
*Chemically inert and non-reactive in most conditions
*Low surface tension
*High thermal stability
*Excellent lubrication properties
*Non-volatile and non-greasy feel
Because of its silicon-oxygen backbone, dimethicone exhibits high flexibility and thermal resistance, making it stable across a wide temperature range.

BENEFITS of DIMETHICONE:
Dimethicone offers several benefits in cosmetic, pharmaceutical, and industrial applications:
*Forms a protective barrier on skin and surfaces
*Helps prevent moisture loss from the skin
*Improves spreadability and texture of formulations
*Provides a smooth, silky feel in cosmetic products
*Reduces friction and irritation
*Acts as an effective lubricant
*Provides water resistance in formulations
*Functions as an antifoaming agent in industrial processes
These properties make dimethicone widely used in skin care, hair care, and industrial lubricants.

PROPERTIES of DIMETHICONE:
Key functional properties include:
*Hydrophobic silicone polymer structure
*Low surface tension
*High viscosity stability across temperatures
*Excellent film-forming capability
*Good compatibility with oils and organic compounds
*Chemically inert and non-reactive in most environments
*High thermal and oxidative stability
*Excellent lubricating and conditioning performance
These properties allow dimethicone to be used in many pharmaceutical, cosmetic, and industrial formulations.

HOW DIMETHICONE WORKS:
Dimethicone creates an invisible film on your skin.
This film retains moisture and keeps the good stuff (like active ingredients) from escaping.
But here’s the catch.
If your product doesn’t have any active ingredients underneath, you’re basically just sealing in nothing.
It’s like wrapping an empty box.
That’s why dimethicone in skin care works best in formulas with ingredients that do something, like hyaluronic acid or various emollients.

WHAT IS DIMETHICONE USED FOR?
Dimethicone is commonly used to hydrate and protect your skin.
Dimethicone may be used to treat or prevent conditions such as the following.
*Chafed, chapped, or cracked skin or lips
*Dry skin due to wind or cold weather
*Itchy skin
*Diaper rash
*Skin irritation from perineal dermatitis, which affects the skin around the genitals and anus, including skin damage from incontinence (trouble controlling when you pee and poop)
*Uses may vary depending on the specific dimethicone product.
*Follow the instructions on the specific dimethicone product you are using.
Dimethicone may also be used for other conditions as determined by your health care provider.

WHAT DIMETHICONE’S USED IN:
You can find dimethicone in many products for many different reasons.
The main places Dimethicone shows up are:

*Cosmetics.
This is because of dimethicone’s ability to smooth the appearance of fine lines and form a protective barrier, Cheung explains.

*Moisturizers and creams.
Dimethicone forms a layer on the skin, thereby locking in hydration and decreasing water loss.

*Shampoo, conditioner, and hairstyling products.
“Dimethicone coats the strands and smooths the cuticles, giving a sleek and shiny look while protecting from heat,” Cheung says.

*Anti-itch products.
Since dimethicone helps moisturize skin and retain water, it can help soothe dry, itchy skin.

DIMETHICONE AT A GLANCE:
*Dimethicone is commonly used emollient, known for its gentleness and silky feel
*Recognised as a skin protectant (in concentrations 1-30%) by the U.S. FDA
*Popular in oil-free moisturisers, thanks to its hydration-enhancing, non-greasy finish
*Dimethicone may also be used in sunscreen formulation to help the actives distribute evenly on skin
*Considered synthetic, even though it’s derived from natural silicon

WHAT IS DIMETHICONE USED FOR?
Dimethicone contributes to the "slip" or "glide" felt upon the application of skincare products, making them spread easily onto the skin.
In addition, dimethicone coats the skin, helping to moisturize it by reducing water loss and providing the skin with softness and coverage—without feeling heavy.

WHO SHOULD USE DIMETHICONE?
Gentle and non-comedogenic (when applied to clean skin), dimethicone is an effective moisturizing ingredient for all skin types.
As a skin protectant at certain levels, dimethicone is especially useful for those whose skin needs an additional barrier that helps prevent moisture from escaping.
Dry, itchy and rough skin may benefit from skincare products that contain dimethicone.

HOW IS DIMETHICONE USED?
Dimethicone can be found in ointments, creams, lotions, serums, sunscreens and lip balms.
To reap its moisturizing and skin-protectant benefits, use these products as directed.

HOW DOES DIMETHICONE WORK?
Dimethicone forms a barrier on the skin that helps minimizes water loss.
Dimethicone also helps improve the skin’s smoothness and flexibility by filling gaps between the cells in the uppermost layer of your skin.

CAN DIMETHICONE BE USED ON THE BODY?
Dimethicone is a gentle, effective moisturizing ingredient for both the face and body.
Dimethicone helps provide long-lasting skin-smoothing benefits, and is ideal for areas prone to rough, dry skin such as knees, elbows, hands and feet, and can help with certain skin conditions like eczema.

STRUCTURE of DIMETHICONE:
The chemical formula of Dimethicone is CH3[Si (CH3)2O]nSi(CH3)3, where n is the number of repeating monomer [Si(CH3)2O] units.
A traditional synthesis entails treating dimethyldichlorosilane with water as described by the following idealized reaction:

n Si(CH3)2Cl2 + nH2O → [Si(CH3)2O]n + 2 HCl
The polymerization reaction evolves hydrochloric acid.

For some domestic applications, a process was developed in which the chlorine atoms in the silane precursor were replaced with acetate groups.
In this case, the polymerization produces acetic acid, which is less chemically aggressive than HCl.
As a side-effect, the curing process is also much slower in this case.

The acetate is used in consumer applications, such as silicone caulk and adhesives.
Commercial routes to Dimethicone usually involve ring-opening polymerization of cyclic siloxanes.

A representative reaction would start with hexamethyltrisiloxane:
n[Si(CH3)2O]3 → [Si(CH3)2O]3n
In reality, a series of ring sizes comprise the precursor cyclic siloxanes.

The reaction is typically catalyzed by base, such as an alkali metal oxide.
The base must be removed when the polymerization is complete.

BRANCHING AND CAPPING of DIMETHICONE:
Hydrolysis of Si(CH3)2Cl2 generates a polymer that is terminated with silanol groups (−Si(CH3)2OH).
These reactive centers are typically "capped" by reaction with trimethylsilyl chloride:
2 Si(CH3)3Cl + [Si(CH3)2O]n−2[Si(CH3)2OH]2 → [Si(CH3)2O]n−2[Si(CH3)2OSi(CH3)3]2 + 2 HCl

Silane precursors with more acid-forming groups and fewer methyl groups, such as methyltrichlorosilane, can be used to introduce branches or cross-links in the polymer chain.
Under ideal conditions, each molecule of such a compound becomes a branch point.

This can be used to produce hard silicone resins.
In a similar manner, precursors with three methyl groups can be used to limit molecular weight, since each such molecule has only one reactive site and so forms the end of a siloxane chain.

Well-defined Dimethicone with a low polydispersity index and high homogeneity is produced by controlled anionic ring-opening polymerization of hexamethylcyclotrisiloxane.
Using this methodology it is possible to synthesize linear block copolymers, heteroarm star-shaped block copolymers and many other macromolecular architectures.
Dimethicone is manufactured in multiple viscosities, from a thin pourable liquid (when n is very low), to a thick rubbery semi-solid (when n is very high).

Dimethicone molecules have quite flexible polymer backbones (or chains) due to their siloxane linkages, which are analogous to the ether linkages used to impart rubberiness to polyurethanes.
Such flexible chains become loosely entangled when molecular weight is high, which results in Dimethicone' unusually high level of viscoelasticity.

MECHANICAL PROPERTIES of DIMETHICONE:
Dimethicone is viscoelastic, meaning that at long flow times (or high temperatures), it acts like a viscous liquid, similar to honey.
However, at short flow times (or low temperatures), Dimethicone acts like an elastic solid, similar to rubber.
Viscoelasticity is a form of nonlinear elasticity that is common amongst noncrystalline polymers.

The loading and unloading of a stress-strain curve for Dimethicone do not coincide; rather, the amount of stress will vary based on the degree of strain, and the general rule is that increasing strain will result in greater stiffness.
When the load itself is removed, the strain is slowly recovered (rather than instantaneously).
This time-dependent elastic deformation results from the long-chains of the polymer.

But the process that is described above is only relevant when cross-linking is present; when it is not, the polymer Dimethicone cannot shift back to the original state even when the load is removed, resulting in a permanent deformation.
However, permanent deformation is rarely seen in Dimethicone, since it is almost always cured with a cross-linking agent.

If some Dimethicone is left on a surface overnight (long flow time), it will flow to cover the surface and mold to any surface imperfections.
However, if the same Dimethicone is poured into a spherical mold and allowed to cure (short flow time), it will bounce like a rubber ball.
The mechanical properties of Dimethicone enable this polymer to conform to a diverse variety of surfaces.

Since these properties are affected by a variety of factors, this unique polymer is relatively easy to tune.
This enables Dimethicone to become a good substrate that can easily be integrated into a variety of microfluidic and microelectromechanical systems.

Specifically, the determination of mechanical properties can be decided before Dimethicone is cured; the uncured version allows the user to capitalize on myriad opportunities for achieving a desirable elastomer.
Generally, the cross-linked cured version of Dimethicone resembles rubber in a solidified form.

Dimethicone is widely known to be easily stretched, bent, compressed in all directions.
Depending on the application and field, the user is able to tune the properties based on what is demanded.
Overall Dimethicone has a low elastic modulus which enables it to be easily deformed and results in the behavior of a rubber.

Viscoelastic properties of Dimethicone can be more precisely measured using dynamic mechanical analysis.
This method requires determination of the material's flow characteristics over a wide range of temperatures, flow rates, and deformations.

Because of Dimethicone's chemical stability, it is often used as a calibration fluid for this type of experiment.
The shear modulus of Dimethicone varies with preparation conditions, and consequently dramatically varies in the range of 100 kPa to 3 MPa.
The loss tangent is very low (tan δ ≪ 0.001).

PHYSICAL and CHEMICAL PROPERTIES of DIMETHICONE:
Substance Name: Dimethicone
Chemical Name: Polydimethylsiloxane (PDMS)
Chemical Class: Silicone polymer / organosilicon compound
Chemical Formula: (C2H6OSi)n or –[Si(CH3)2–O]n–
Molecular Structure: Linear polymer composed of repeating dimethylsiloxane units
CAS Numbers:
CAS Number (commonly used): 9006-65-9
Other CAS Numbers: 63148-62-9, 9016-00-6, 141-62-8

EC Numbers:
EC Number: 205-491-7
EC Number (alternative listing): 205-492-2
Appearance: Clear, colorless, viscous liquid or fluid
Odor: Odorless or nearly odorless
Physical State: Liquid polymer (viscosity varies depending on molecular weight)
Molecular Weight: Variable polymer; typically ~1000–2000 g/mol depending on grade
Density: ~0.95–1.0 g/cm³ at 20 °C

Viscosity: Typically 5–1,000,000 cSt depending on grade
Flash Point: about 121 °C or higher depending on viscosity
Boiling Point: >200 °C (polymeric material)
Pour Point: about −50 °C
Refractive Index: ~1.40
Vapor Pressure: very low (low volatility)
Solubility in Water: practically insoluble
Solubility in Organic Solvents: soluble in many organic solvents and oils
pH: neutral
Stability: stable under normal storage conditions

FIRST AID MEASURES of DIMETHICONE:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation: 
Fresh air.
*In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact: 
Rinse out with plenty of water. 
Call in ophthalmologist. 
Remove contact lenses.
*If swallowed:
After swallowing: 
Immediately make victim drink water (two glasses at most). 
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available

ACCIDENTAL RELEASE MEASURES of DIMETHICONE:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions. 
Take up dry. 
Dispose of properly. 
Clean up affected area.

FIRE FIGHTING MEASURES of DIMETHICONE:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2) 
Foam 
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of DIMETHICONE:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection. 
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A 
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of DIMETHICONE:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed. 
Dry.

STABILITY and REACTIVITY of DIMETHICONE:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature).
-Possibility of hazardous reactions:
No data available