
Descriptions
Chemical Name: Polyisobutylene
CAS #: 9003-27-4
Average Molecular Weight (Mn)
Kemulene 1300: 1,150~1,450
Kemulene 2400: 2,150~2,650
Features
Kemulene low molecular weight polyisobutylene (LMW PIB) typically refers to polyisobutylene with a number average molecular weight (Mn) ranging from a few hundred to around 10,000 g/mol. This lower molecular weight range gives LMW PIB distinct properties compared to its medium and high molecular weight counterparts.
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Viscous Liquid or Semi-Solid: At room temperature, LMW PIB generally exists as a colorless to yellowish, transparent viscous liquid or a semi-solid material, depending on the specific molecular weight.
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Tackiness (Stickiness): LMW PIB exhibits significant tackiness, making it useful in adhesives and sealants. The degree of tackiness increases with molecular weight within the low range.
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Low Viscosity: Compared to higher molecular weight PIBs, LMW PIB has a lower viscosity, making it easier to handle and process in liquid formulations.
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Good Solubility: It is soluble in nonpolar organic solvents like gasoline and benzene but insoluble in water and alcohols.
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Excellent Shear Stability: LMW PIB maintains its viscosity even under high shear forces, which is crucial in lubricant applications.
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Thermal and Oxidative Stability: It possesses good resistance to heat and oxidation, contributing to its long-term performance.
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Chemical Resistance: LMW PIB shows good resistance to acids, alkalis, and ozone.
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Low Glass Transition Temperature (Tg): This property ensures flexibility and performance even at low temperatures.
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Gas Impermeability: While higher molecular weight PIB has superior gas barrier properties, LMW PIB still offers reasonable resistance to gas permeation.
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Clean Burn-off: In some applications like two-stroke engine oils, LMW PIB can burn cleanly with minimal residue.
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Non-Toxic and Odorless: Generally considered non-toxic and odorless, making it suitable for a wider range of applications, including some cosmetic and food-related uses.
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Hydrophobicity: It repels water, providing moisture resistance in sealants and other applications.
Applications
Kemulene low molecular weight polyisobutylene is a versatile polymer with a unique combination of properties, making it essential in a wide array of industrial and consumer applications, particularly in lubricants, adhesives, sealants, and personal care products.
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Lubricant and Fuel Additives:
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Viscosity Modifier: Used to improve the viscosity index of lubricating oils, ensuring stable viscosity across a wide temperature range. It can be an economical alternative to high-viscosity base oils.
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Dispersant Intermediate: A key raw material in the production of ashless dispersants (like PIB succinimide), which prevent sludge and deposit formation in engines.
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Thickener: Can act as a thickener in certain lubricant formulations.
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Fuel Detergent: Helps keep fuel systems clean and reduces deposits.
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Two-Stroke Engine Oil: Formulated into two-stroke oils for lubrication and to reduce smoke emissions.
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Gear Oils, Hydraulic Oils, Metalworking Fluids: Improves the performance and stability of these industrial lubricants.
Adhesives, Sealants, and Coatings:
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Pressure Sensitive Adhesives (PSA): Its inherent tackiness makes it a valuable component in various PSAs like tapes and labels.
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Hot Melt Adhesives: Used as a base polymer or modifier in hot melt adhesive formulations.
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Sealants: Employed in caulks, sealants for insulating glass, automotive sealants, and waterproofing materials due to its flexibility, moisture resistance, and adhesion.
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Coatings: Acts as a viscosity modifier and improves the flexibility and durability of certain coatings.
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Tackifier: Added to other polymers and rubber compounds to increase their tack.
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Cable Filling Compounds: Used as a water-blocking agent in telecommunication cables.
Polymer Modification:
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Impact Modifier: Can be blended with other polymers like polyethylene to improve impact strength and flexibility, particularly at low temperatures.
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Cling Film: Improves the cling properties of polyethylene films used for food packaging.
Cosmetics and Personal Care:
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Emollient: Provides a soft and smooth feel to the skin.
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Viscosity Control Agent: Helps to adjust the thickness and consistency of cosmetic formulations like lipsticks, lotions, and creams.
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Gloss Enhancer: Adds shine to products like lip glosses.
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Film Former: Can create a water-resistant film on the skin or lips.
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Pigment Dispersion Stabilizer: Helps to evenly distribute pigments in makeup products.
Other Applications:
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Chewing Gum Base: A component in some chewing gum formulations.
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Explosives: Used as a binder in certain explosive compositions.
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Food Packaging: Used in some films and coatings for its moisture barrier properties and non-toxic nature.
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Electrical Insulation: Its good dielectric properties make it suitable for some electrical insulation applications.