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Recommended products

Recommended products for thickening and thixotropy in liquid resins

Unsaturated polyester resins are relatively non polar, as in most cases the reactive diluent styrene is used. For this reason, hydrophilic AEROSIL® fumed silica is the thickening agent of choice. AEROSIL® 200 is widely used for laminating resins and gel coats. Nowadays the more efficient product AEROSIL® 200 HV is recommended.

Some specialty polyester resins and vinyl ester resins, which have more polar character, require hydrophobic AEROSIL® products. AEROSIL® R 202 performs excellent in such formulation, while hydrophilic AEROSIL® fumed silica will not give sufficient thickening efficiency.

The following table shows the typical applications and effects for the use of AEROSIL® and SIPERNAT® products in UP resins and gives recommendations for grades and dosage.

Gel coat

Application

Effect

Product

Dosage
[wt.%]

Remark

Clear

Rheology

AEROSIL®

200 /

AEROSIL®

200 HV

1.0-2.0

 

Filled/ colored
w/talc, TiO2 etc.

Rheology
Porosity

AEROSIL®

200 /

AEROSIL®

200 HV

SIPERNAT®

22 LS

2.5-4.5

Ratio 40 percent

(AEROSIL®

200) with 60 percent (SIPERNAT®

22 LS) to start. Similar usage in putties and pastes

Dark colored
non-white

Rheology
Blush Resistance

AEROSIL®

200 /

AEROSIL®

200 HV

SIPERNAT®

FPS-5

2.5-4.5

For marine gel coat
High purity ppt. silica

General

Rheology control
Mechanical properties

AEROSIL®

R 202, AEROSIL®

R 208

6.0-10.0

In most cases based on VE and EP resin. When UP resin is used AEROSIL®

200 HV is recommended

Laminating resin

Application

Effect

Product

Dosage
[wt.%]

Remark

General

Rheology control

AEROSIL®

200 /

AEROSIL®

200 HV

0.8-1.3

 

Low styrene

Rheology control

AEROSIL®

200 /

AEROSIL®

200 HV

SIPERNAT®

22 LS

0.8-2.5

For environmental resins
Rising viscosity with less solvent

General

Rheology control
Mechanical properties

AEROSIL®

R 202, AEROSIL®

R 208

6.0-10.0

In most cases based on VE and EP resin. When UP resin is used AEROSIL®

200 HV is recommended

Bonding paste

Application

Effect

Product

Dosage
[wt.%]

Remark

General

Rheology control
Mechanical properties

AEROSIL®

R 202, AEROSIL®

R 208

6.0-10.0

In most cases based on VE and EP resin. When UP resin is used AEROSIL®

200 HV is recommended

The data represents typical values