Technical Library

These include lower molecular weight siloxanes with discrete structures and higher molecular weight silicones with either pendant or terminal epoxy functionalization. Depending on specific structures and formulations, they selectively impart a wide range of properties associated with silicones⁠—low-stress, low temperature properties, dielectric properties, and release. Properties of cured silicone-modified epoxies vary from hydrophilic to hydrophobic depending on the epoxy content, degree of substitution, and ring-opening of epoxides to form diols. The ring-strained epoxycyclohexyl group is more reactive than the epoxypropoxy group and undergoes thermally- or chemically-induced reactions with nucleophiles including protic surfaces such as cellulosics of polyacrylate resins.

The compatibility of epoxy-functional silicones with conventional epoxies varies. In simple unfilled systems, total solubility is required. For filled systems, it is often desirable to consider systems that are miscible but have only limited solubility since microphase separation can allow a mechanism for stress-relief. Epoxysilicones with methoxy groups can be used to improve adhesion to substrates such as titanium, glass, or silicon. They also can improve chemical resistance of coatings by forming siloxane crosslinks upon exposure to moisture.

A UV initiator for cycloaliphatic epoxides is OMBO037 described in the photoinitiators section. Epoxy-functional siloxane copolymers with polyalkyleneoxide functionality provide hydrophilic textile finishes.

Silicone-Epoxy Compatiblity

Gelest ProductEpoxy Type - BisphenolEpoxy Type - PolyglycolEpoxy Type - Cycloaliphatic
SIB1092.0misciblesolublesoluble
SIB1110.0solublesolublesoluble
SIB1115.0solublesolublesoluble
SIG5820.0insolubleinsolublesoluble
MCR-E11insolubleinsolubleinsoluble
MCS-E15insolubleinsolubleinsoluble
DMS-E09solublesolublesoluble
DMS-E11insolublemisciblemiscible
PMS-E11solublesolublesoluble
ECMS-127insolubleinsolubleinsoluble
EMS-622insolublemiscibleinsoluble
10% silicone, 90% epoxy

Difunctional Low MW Siloxanes

Product CodeStructureNameMolecular WeightBP/mm (MP) (°C)Density
D420
Refractive Index
nD20
CommentsCAS
SIB1092.0bis[2-(3,4-epoxycyclohexyl)ethyl]-tetramethyldisiloxane, 90%382.69(-34)0.9981.4758flashpoint: 200 °C
viscosity: 40 cSt
UV-initiated polymerization with weak acid donors
[18724-32-8]
TSCA
SIB1110.01,5-bis(glycidoxypropyl)-3-phenyl-1,1,3,5,5-pentamethyltrisiloxane498.84--1.1061.4763monomer for silicone-modified epoxy resins--
SIB1115.01,3-bis(glycidoxypropyl)tetramethyl-disiloxane362.61184-187/2
(-46 to -50)
0.9961.452flashpoint: 110°C
viscosity: 10-12 cSt
monomer for silicone-modified epoxy resins
end-capper for epoxy-terminated silicones
[126-80-7]
TSCA

Epoxypropoxypropyl-Terminated Polydimethylsiloxanes, CAS: [102782-97-8], TSCA

Product CodeViscosity (cSt)Molecular WeightEpoxy (eq/kg)Refractive IndexDensity
DMS-E098-113635.51.4460.99
DMS-E1112-18500-6001.9-2.21.4190.98
DMS-E1220-351,000-1,4001.6-1.91.4170.98
DMS-E21100-1404,500-5,5000.35-0.451.4080.98
Used in preparation of photocurable silicone for soft lithography. Used in preparation of photocurable silicone for soft lithography. (Choi, D. et al, JACS, 2003, 125, 4060)

Epoxycyclohexylethyl-Terminated Polydimethylsiloxanes, CAS: [102782-98-9], TSCA

Product CodeViscosity (cSt)Molecular WeightEpoxy (eq/kg)Refractive IndexDensity
DMS-EC1325-35900-1,0001.9-2.01.4330.99
DMS-EC1760-803,200-3,6000.5-0.71.4120.98
DMS-EC31800-1,20040,0000.04-0.061.4100.98
see also [button skus="SIB1092.0"]SIB1092.0[/button]

Epoxypropoxypropyl-Terminated Polyphenylmethylsiloxanes, CAS: [102782-98-9], TSCA

Product CodeViscosity (cSt)Molecular WeightEpoxy (eq/kg)Refractive IndexDensity
PMS-E1115-30500-6003.0-3.61.4751.01
PMS-E1530-501,200-1,5001.0-1.71.4901.01

(Epoxypropoxypropyl)dimethoxysilyl-Terminated Polydimethylsiloxane, CAS: [188958-73-8], TSCA

Product CodeViscosity (cSt)Molecular WeightEpoxy (eq/kg)Refractive IndexDensity
DMS-EX2180-1203,500-4,0000.48-0.51.4080.98

Multifunctional Low MW Siloxanes

Product CodeStructureNameMolecular WeightBP/mm (MP) (°C)Density
D420
Refractive Index
nD20
CommentsCAS
SIT8715.6tris(glycidoxypropyldimethylsiloxy)-phenylsilane, 95%673.11(-73)1.051.474225viscosity: 30-35 cSt
amber liquid
[90393-83-2]
SIT7281.5tetrakis[(epoxycyclohexyl)ethyl]tetramethyl-cyclotetrasiloxane, tech-95737.23--1.141.487viscosity: 300 cSt.
polymerized by cationic photoinitiators or anhydrides
[121225-98-7]

(Epoxycyclohexylethylmethylsiloxane)-Dimethylsiloxane Copolymers, CAS: [67762-95-2], TSCA

Product CodeViscosity (cSt)Molecular WeightEpoxy (eq/kg)Refractive IndexDensity
MCR-E11500-1,20012,000-15,0001-21.4070.98
MCR-E11650-80018,000-20,0002-31.4070.98
MCR-E11350-85018,000-20,0003-41.4090.99
MCR-E11300-45010,000-12,0008-101.4210.97

(Epoxypropoxypropylmethylsiloxane)-(Dimethylsiloxane) Copolymer, CAS: [68440-71-7], TSCA

Product CodeViscosity (cSt)Molecular WeightEpoxy (eq/kg)Refractive IndexDensity
EMS-622200-3007,000-9,0005-71.4120.99

(2-3% Epoxycyclohexylethylmethylsiloxane)(10-15% Methoxypolyalkyleneoxymethylsiloxane)-(Dimethylsiloxane) Terpolymer, CAS: [69669-36-9], TSCA

Product CodeViscosity (cSt)Molecular WeightEpoxy (eq/kg)Refractive IndexDensity
EBP-2344,000-5,00025,000-36,0000.75-0.801.4451.03