Nanjing SiSiB Silicones Co., Ltd.
Nanjing SiSiB Silicones Co., Ltd.
OH Silicone Polymer

OH Silicone Polymer

The fundamental building block of a silicone sealant is cyclic and polymeric siloxane. This is often represented by Silanol end-capped Polydimethylsiloxane.


The silanol (-OH) terminated silicone based polymer is the basis for the formulation of one component, moisture curing RTV structural silicone sealant, and two-component, condensation curing RTV silicone compounds.


These organosilicon siloxane polymers are available in a wide range of viscosities.


OH Silicone Polymer


SiSiB® PF1070 OH polymer is intermediate and high viscosity silanol terminated fluids, 750~100,000 CST. The silicon containing polymers are recommended for formulating silicone RTV systems that incorporate reinforcing and extending fillers.


OH Silicone Polymer PF1070 can be cured with usual condensation crosslinkers such as alkoxy silanes, acetoxy silanes, oxime silanes and enoxy silanes in connection with catalysts. Other properties of silicone polymers are listed as follows:  


Product

Appearance

Viscosity (25°C)

Volatile (%)

SiSiB® PF1070-750

Transparent liquid

750 CST

Max. 1.5

SiSiB® PF1070-1500

Transparent liquid

1,500 CST

Max. 1.5

SiSiB® PF1070-2000

Transparent liquid

2,000 CST

Max. 1.5

SiSiB® PF1070-3500

Transparent liquid

3,500 CST

Max. 1.5

SiSiB® PF1070-5000

Transparent liquid

5,000 CST

Max. 1.5

SiSiB® PF1070-10000

Transparent liquid

10,000 CST

Max. 1.5

SiSiB® PF1070-20000

Transparent liquid

20,000 CST

Max. 1.5

SiSiB® PF1070-50000

Transparent liquid

50,000 CST

Max. 1.5

SiSiB® PF1070-80000

Transparent liquid

80,000 CST

Max. 1.5

SiSiB® PF1070-100K

Transparent liquid

100,000 CST

Max. 1.5

SiSiB® PF1070-150K

Transparent liquid

150,000 CST

Max. 1.5

SiSiB® PF1070-300K

Transparent liquid

300,000 CST

Max. 1.5

SiSiB® PF1070-1000K

Transparent liquid

1,000,000 CST

Max. 1.5

RTV silicone sealants are often defined and characterized by their modulus - high, medium, and low. The following guidelines are generally employed in the formulation of each type.

High modulus

Use low viscosity silanol polymer, high fumed silica or treated fumed silica, and tetra- or greater functionality crosslinker.

Medium modulus

Use medium to high viscosity silanol polymer, medium to high silica levels, calcium carbonate and silicone plasticizer.

Low modulus

Use high viscosity silanol polymer, polymer chain extenders (the silanol polymer is chain extended which decreases the crosslinking density), zero to low silica levels, high calcium carbonate level, and silicone plasticizer.