Technical Library

Hybrid fluids combine the properties of organic materials with siloxanes in order to create structures that:

  • Achieve unique skin feel
  • Improve wear properties
  • Improve solubility
  • Lower surface tension
  • Introduce a dimethicone slip with a light natural feel
  • Allow greater formulation latitude
  • Improve perfume retention
  • Enhance dispersion of pigments and fillers
  • Offer compatibility with natural cosmetic ingredients

Gelest offers two classes of hybrid fluids:

  • SiBrid® Fluids: Hydrocarbon Hybrids. Organic modified siloxanes that cross the boundaries between organics and silicones. SiBrid® fuids are soluble in most organics and silicones.
  • Vertasil® Fluids: Naturalized Hybrids. High natural product content derived silicones. Vertasil® fuids are natural products modified by incorporation of oligomeric siloxanes that offer reduced surface tension, increased spreadability, and enhanced compatibility.

Gelest Specialty Silicone Fluids Summary

ProductRefractive IndexViscosity (cSt)INCI NameGlobalClaims/CertificationsFeatures:
Reduced Tack
Water Resistance
Skin Care
Sun Care
Hair Care
Bath and Body
SiBrid® Diethicone DE-121.43815-20PolydiethylsiloxaneGReduces tack,
Slip enhancer,
Good solubilizer
• • •• • •• • •• •
SiBrid® Diethicone DE-151.44240-50PolydiethylsiloxaneGReduces tack,
Slip enhancer
• • •• • •• •• •
SiBrid® Diethicone DE-231.447250-350PolydiethylsiloxaneGEmollient• •• •• • •• •
SiBrid® Polyethylene Dimethicone Block Polymer--45Polyethylene Dimethicone--Reduces tack,
Slip enhancer,
Improves skin feel
• •• •
SiBrid® Bispolyethylene/Dimethicone--65Bispolyethylene Dimethicone--Reduces tack,
Slip enhancer,
Improves skin feel
• •• •
SiBrid® Ethylene/Dimethicone Copolymer1.431100Ethylene Polydimethylsiloxane Copolymer (proposed)--Compatibilizer and stabilizer for silicone organic formulations• •• •
SiBrid® Lauryl Phenylpropylmethicone 1.4641,500Lauryl Phenylpropyl Methicone--High refractive index,
Shine enhancer,
Improves wear and skin adhesion
SiBrid® Propyltrisiloxane1.3991-2Propyl Trisiloxane--D5 alternate solubilizer• • •• • •
SiBrid® Caprylyl Methicone1.4133Caprylyl MethiconeGSlip enhancer,
• • •• • •• • •• • •
SiBrid® Lauryl Methicone1.4315-6Lauryl Methicone--Emollient,
Slip enhancer
• •• •• •• •
SiBrid® Stearyl Methicone1.43312-13Stearyl Methicone--Emollient,
Slip enhancer
• • •
Vertasil® Anisyl Dimethicone1.437-8Bis(methoxyphenyl propyl/butyl) Dimethicone--Slip enhancer,
Improves shine
• •
Vertasil® omega-Limonenyl Dimethicone1.4247-8Bis(methylcyclohexenyl isopropyl/butyl) Dimethicone--Cleansing,
• •
Vertasil® Limonenyltrisiloxane1.4264-5Methylcyclohexenyl Isopropyl Trisiloxane--Cleansing,
• • •• • •• • •
Vertasil® Tocopheryloxypropyltrisiloxane1.472700Tocopheryloxypropyl
Film Former
• • •• • •• •

A variety of technologies are employed by Gelest to combine natural and organic functionality with siloxane structures to form new hybrid polymer architectures.

The introduction of natural or organic components into siloxanes usually constitutes initiation, termination, graft copolymer and block polymerization methods. The natural and organic hybrids discussed throughout this page represent materials with both utility and impact in cosmetic formulations. In another sense, these materials are simply examples of the possibilities this technology platform offers for innovation.

Hybrid fluids extend the range of organic and natural products by introducing alternating silicon and oxygen bond segments into their structure. The alternating silicon-oxygen segments have exceptionally low barriers to rotation leading to molecular flexibility. The result is that the desirable characteristics of organic and natural products are extended—greater emolliency, wider ranges of liquid behavior, and broader formulation options. The ability of hybrid fluids to cross compatibility barriers not only allows them direct applicability in both organic and silicone formulations but allows them to act as co-compatibilizing additives.

A useful illustration to distinguish the difference of pure organic systems with siloxane systems is to consider the differences between polyisobutylene and polydimethylsiloxane. The molecular scaffold of polyisobutylene is constrained by the rotational barrier of the carbon-carbon bond (3.3 kcal/mole) while the molecular scaffold of polydimethylsiloxane is essentially unconstrained since the rotational barrier of the silicon oxygen bond is essentially zero. The carbon-carbon bond is also shorter than the silicon-oxygen bond, resulting in more tightly packed molecular structures for pure organics. Among other effects, siloxanes allow permeation of moisture and oxygen. At the same time, the strength of the silicon-oxygen bond is greater than the strength of the carbon-carbon bond.



Properties of Hydrocarbons vs Siloxanes

Glass Transition, Tg-70 °C-123 °C
Viscosity, n=10570 cSt5 cSt
Viscosity, n=1005,000,000 cSt140 cSt
Surface Tension33 mN/m22 mN/m
Oxygen Permeability0.81 cm3-cm/cm2 •s•cmHg60 cm3-cm/cm2 •s•cmHg

These fundamental differences in properties of siloxanes compared to hydrocarbons offer advantages in product formulations due to:

  • Low surface energy
  • Wide viscosity range
  • Spreading behavior
  • Lower reactivity
  • Biocompatibility
  • UV-resistance
  • Modified hydrophilic-lipophilic balance