Quick Search
DESCRIPTION
Polydimethylsiloxane (PDMS) 350 CST is a type of silicone fluid with a specific viscosity of 350 centistokes (cSt) at 25°C.
This material is part of a family of organosilicon compounds, primarily composed of repeating units of silicon-oxygen bonds (Si-O).
PDMS is widely known for its stability, low surface tension, and unique combination of physical properties such as low volatility, high thermal stability, and resistance to oxidation.
Cas Number
63148-62-9
Synonyms
Dimethicone,Silicone oil,Polysiloxane, Dimethylpolysiloxane,Silicone fluid,PDMS fluid
Polydimethylsiloxane (PDMS) is a highly versatile silicone polymer known for its unique chemical and physical properties, making it ideal for a wide range of industrial, medical, and consumer applications.
PDMS consists of a repeating siloxane (Si–O) backbone with methyl groups (CH₃) attached to the silicon atoms.
Among various PDMS variants, the 350 cSt grade stands out for its specific viscosity and is widely used in applications where medium viscosity and excellent performance are required.
Overview of PDMS: PDMS is a type of silicone elastomer used in products ranging from medical devices to electronics and personal care products.
Its combination of thermal stability, flexibility, low surface tension, and biocompatibility makes it an attractive material in a variety of sectors.
Importance of PDMS 350 cSt: PDMS 350 cSt is specifically chosen for applications that require a balanced viscosity, offering a compromise between high flow and low viscosity PDMS grades like 10 cSt and very high viscosity grades like 1000 cSt.
This makes PDMS 350 cSt ideal for applications requiring precise control of fluid movement and structural properties.
Applications: The 350 cSt variant of PDMS is commonly used in microfluidics, as a lubricant, in cosmetics, and as a key material in the manufacturing of medical devices such as implants and catheters.
Chemical Composition: The backbone of PDMS consists of alternating silicon (Si) and oxygen (O) atoms.
Each silicon atom is bonded to two methyl (CH₃) groups.
This structure imparts flexibility and stability, contributing to its low surface energy and hydrophobic nature.
Molecular Structure: The repeating unit of PDMS is typically represented as (–SiO–)n, where 'n' denotes the number of repeating units.
The methyl groups attached to each silicon atom contribute to PDMS's non-polar nature and give it its characteristic hydrophobicity.
Viscosity: The viscosity of PDMS is highly dependent on molecular weight, chain length, and the degree of polymerization.
For PDMS 350 cSt, this viscosity is achieved by controlling the polymerization process to produce medium-length polymer chains.
The "cSt" refers to centistokes, a unit of kinematic viscosity, indicating the flow rate and resistance of the fluid under given conditions.
Thermal Properties: PDMS is known for its excellent thermal stability.
It can withstand a wide range of temperatures, typically from -50°C to +250°C, without significant degradation.
Its high melting point and low thermal conductivity make it suitable for high-temperature applications.
Optical Properties: PDMS 350 cSt is transparent, which makes it a good choice for optical and photonics applications.
Its refractive index is relatively close to that of glass, making it useful for optical lenses and light guides.
Electrical Properties: While PDMS is an insulating material, it has a low dielectric constant, which can make it useful for certain electronic applications where minimal interference is needed.
However, its insulating properties may be limited in high-frequency circuits.
Viscosity and Its Role in PDMS 350 cSt
Definition of 350 cSt: Viscosity is a measure of a material’s resistance to flow.
For PDMS, the viscosity is measured in centistokes (cSt), where 1 cSt = 1 mm²/s. A viscosity of 350 cSt indicates a medium viscosity silicone fluid, which flows more slowly than lower viscosity grades like 10 cSt but is more fluid than high-viscosity variants like 1000 cSt.
Factors Affecting Viscosity: Viscosity is influenced by molecular weight (or chain length), temperature, and the presence of additives such as crosslinkers or fillers.
PDMS's viscosity can be modified by altering the polymerization process or by introducing specific chemical modifications.
Temperature Dependence: The viscosity of PDMS decreases with increasing temperature.
This behavior is particularly important for its use in high-temperature environments or as a fluid in temperature-sensitive applications.
Comparison with Other Grades: PDMS 350 cSt offers an optimal viscosity for applications requiring a balance between ease of handling and structural integrity.
While low-viscosity PDMS is ideal for coatings or thin-film applications, high-viscosity variants are typically used for structural components requiring higher thickness.
Manufacturing and Synthesis of PDMS 350 cSt
Polymerization Process: PDMS is synthesized through a ring-opening polymerization process involving the reaction of cyclic siloxanes (typically octamethylcyclotetrasiloxane, D4) with water or silane catalysts.
The polymer chains are formed by linking the cyclic monomers into long linear chains.
Precursors and Catalysts: The key precursors in PDMS production include silanes, siloxanes, and the polymerization catalysts, which are often metal-based (e.g., tin or platinum-based catalysts).
These control the polymerization rate and molecular weight of the resulting PDMS.
Adjusting Viscosity: The viscosity of PDMS can be controlled by modifying the polymerization reaction conditions such as temperature, catalyst concentration, and reaction time.
The introduction of low-molecular-weight components can reduce viscosity, while crosslinking agents can increase it.
Industrial Considerations: In large-scale production, the synthesis of PDMS 350 cSt requires careful control to achieve the desired molecular weight distribution and viscosity.
Processes like batch reactors or continuous flow reactors may be used, depending on the required output and consistency.
Characterization Methods for PDMS 350 cSt
Rheological Testing: Viscosity is often measured using rheometers that apply a controlled shear rate to the material and measure its flow resistance.
The shear rate dependency can provide further insight into the material’s behavior under different flow conditions.
Thermal Analysis: Techniques such as Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) are used to assess the thermal stability and glass transition temperature of PDMS. TGA can determine the degradation temperatures, while DSC can measure the heat flow associated with phase transitions.
Spectroscopic Techniques: Fourier Transform Infrared (FTIR) spectroscopy and Nuclear Magnetic Resonance (NMR) spectroscopy are employed to investigate the chemical structure of PDMS.
These methods can confirm the purity of PDMS and identify any impurities or degradation products.
Microscopic Analysis: Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) are used to study the surface morphology of PDMS.
These techniques can reveal information about the surface roughness, microstructure, and any phase separation in PDMS composites.
Mechanical Property Testing: PDMS 350 cSt can undergo tensile testing, hardness testing, and elongation tests to assess its mechanical properties. The results help understand its flexibility, strength, and potential use in structural applications.
Applications of PDMS 350 cSt
Medical Devices: Due to its biocompatibility, PDMS is widely used in medical devices, such as catheters, implants, and drainage tubes.
Its flexibility, low toxicity, and stability in physiological conditions make it an excellent choice for long-term use in the human body.
Microfluidics: PDMS 350 cSt is particularly well-suited for creating microfluidic devices, where it is used for molding microchannels and controlling fluid flow within lab-on-a-chip systems.
Its low viscosity allows precise manipulation of fluids.
Electronics and Optoelectronics: PDMS is employed in electronics, including encapsulating components and producing flexible electronics.
It’s also used in the fabrication of optical devices such as lenses and light guides due to its transparency and optical properties.
Cosmetics and Personal Care: In the personal care industry, PDMS 350 cSt is used as a base material for lotions, hair care products, and skin treatments.
Its lubricating properties and skin compatibility make it ideal for creating smooth and long-lasting products.
Lubricants, Coatings, and Adhesives: PDMS 350 cSt is frequently used as a lubricant due to its low friction coefficient.
It is also used in coatings and adhesives for applications requiring moisture resistance and a smooth finish.
Food Contact Materials: PDMS 350 cSt is used in food processing, particularly in molding, anti-stick coatings, and release agents.
PDMS 350 cSt in Biomedical and Healthcare Applications
Biocompatibility: PDMS 350 cSt is highly biocompatible, making it suitable for use in long-term medical implants and devices.
It has low immunogenicity and is well-tolerated by the human body.
However, ongoing research continues to explore potential toxicity under specific conditions.
Drug Delivery: PDMS can be used in controlled drug delivery systems, where it can be modified to release drugs in a sustained and controlled manner.
Its permeability and elasticity make it suitable for this application.
Prosthetics and Implants: PDMS 350 cSt is ideal for creating prosthetic components, especially for implants that require a flexible and durable material that can withstand repeated mechanical stress.
Tissue Engineering: PDMS is used as a scaffold in tissue engineering, particularly in regenerating soft tissues. Its ability to mimic natural tissue properties aids in cell growth and tissue repair.
Biological Fluid Interaction: PDMS’s interaction with biological fluids is studied to ensure that it does not cause adverse reactions, such as inflammation or cytotoxicity, when in contact with the body.
Environmental Impact and Sustainability
Biodegradability: PDMS is not easily biodegradable, which presents challenges for its disposal.
Researchers are exploring ways to improve the environmental footprint of PDMS, such as developing more biodegradable forms of silicone polymers.
Recyclability: While PDMS can be mechanically recycled in some cases, its complex polymer structure often limits traditional recycling methods. Newer methods focus on breaking down PDMS into its monomers for reuse.
Environmental Concerns: The production and disposal of PDMS can have environmental impacts, particularly regarding the persistence of waste in landfills. Sustainable manufacturing processes are being researched to reduce these impacts.
Recycling Innovations: Some advancements in recycling PDMS involve chemical degradation processes, where the polymer is broken down into its constituent parts and can be reprocessed or used for other applications.
Sustainable Sourcing: Sustainable production practices focus on minimizing the use of toxic catalysts and reducing the carbon footprint of the manufacturing process.
Future Trends and Research Directions
Innovations in PDMS Formulation: Researchers are continuously exploring new ways to modify PDMS, such as creating more temperature- or light-responsive versions of the material that can be used in smart devices and sensors.
Smart Materials: PDMS is being integrated into smart materials that can change their properties in response to external stimuli (e.g., temperature, pressure, or light), opening new possibilities in fields like wearable sensors and biomedical devices.
Wearable Electronics: PDMS 350 cSt is ideal for flexible, wearable electronics that require both durability and comfort.
Its ability to conform to the skin makes it particularly well-suited for health-monitoring devices.
Renewable Energy Applications: PDMS is being explored for use in renewable energy, such as solar cells and energy storage devices, where its properties help improve performance and efficiency.
Challenges in Material Science: As demand for PDMS in emerging fields grows, ongoing research will address challenges in scalability, cost reduction, and environmental impact.
Polydimethylsiloxane 350 cSt remains a crucial material across multiple industries, from biomedical devices to electronics and consumer products.
Its unique combination of properties, such as flexibility, stability, and biocompatibility, has led to its widespread use. With ongoing research and development, PDMS 350 cSt will continue to evolve, paving the way for innovations in many fields.
The challenges related to its environmental impact are being actively addressed, and future applications will likely expand into new, high-tech areas.
PDMS 350 cSt represents a key material in the advancement of materials science and industrial applications.
SAFETY INFORMATION ABOUT POLYDIMETHYLSILOXANE 350 CST
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product.
