Products Tested

The elastomer compatibility of various polyalkylene glycols (PAGs) was determined. The polymers tested in this study are listed below:

WATER SOLUBLE

UCON Lubricant 50-HB-170

UCON Lubricant 50-HB-660

UCON Lubricant 50-HB-5100

UCON Lubricant 75-HB-1400

WATER INSOLUBLE

UCON Lubricant LB-135

UCON Lubricant LB-625

UCON Lubricant LB-1715

Elastomers Identification

Each of the elastomers tested was immersed in each of the PAG fluids for 95 days at 100℃. The elastomers are identified below:

Aflas

Butyl

Buna N

Buna S

EPDM

Fluorosilicone

Fluoraz

Gum Rubber

Kalrez 4097

Neoprene

Silicone

Viton A

Tetrafluoroethylene and Propylene Copolymer

Isobutylene Isoprene Polymer

Butadiene-Acrylonitrile Copolymer

Butadiene-Styrene Copolymer

Ethylene Propylene Copolymer

Fluorinated Silicone Polymer

Modified Tetrafluoroethylene and Propylene Copolymer

Natural Isoprene Polymer

Perfluorocarbon Polymer

Chloroprene Polymer

Organic Silicone Polymer

Fluorocarbon Polymer

Water-Soluble PAGs – Test Data

Tables 1-5 contain the test data from which the following general conclusions may be drawn:

1. According to the test data, all of the elastomers will provide fair-to-excellent service in all of the PAG fluids tested in this study.

2. Viton, EPDM, silicone, and butyl elastomers were sufficiently resistant to all of the PAG fluids to be resistance-rated 1 or 2, meaning these elastomers showed good resistance to the fluids under the test conditions. Viton, EPDM, silicone and butyl elastomers are commonly used and stocked materials. The Fluoraz, Kalrez, fluorosilicone and Aflas elastomers were also resistant with 1 or 2 ratings, but these fluoropolymers are specialty products and are not always available.

3. All of the test elastomers were compatible with 50-HB-170 and given a 1 or 2 rating.

4. The poorest performing elastomers were the nitrile compounds, Buna N and Buna S. Viton and EPDM elastomers both performed well in all of the fluids. Silicone and butyl are the next preference.

Due to the wide variability in compositions and specifications for elastomers with the same general name (e.g., Buna-N), customers should test the actual elastomers in their system to determine compatibility.